Sotalol: Difference between revisions

Jump to navigation Jump to search
mNo edit summary
m (Protected "Sotalol": Bot: Protecting all pages from category Drug ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite)))
 
(19 intermediate revisions by 4 users not shown)
Line 1: Line 1:
{{Sotalol}}
{{DrugProjectFormSinglePage
{{drugbox |
|authorTag={{Alonso}}, {{SS}}, {{RB}}
| IUPAC_name = ''N''-[4-(1-hydroxy-2-isopropylamino-<br>ethyl)-phenyl]-methanesulfonamide
|genericName=Sotalol
| image = Sotalol.png
|aOrAn=a
| CAS_number = 3930-20-9
|drugClass={{beta-adrenergic blocker}}, {{antiarrhythmic}}
| ATC_prefix=C07
|indicationType=treatment
| ATC_suffix=AA07
|indication=[[ventricular arrhythmias]], symptomatic [[atrial fibtillation]], symptomatic [[atriall flutter]]
| PubChem=5253
|hasBlackBoxWarning=Yes
| DrugBank=
|adverseReactions=[[bradyarrhythmia]], [[chest pain]], [[lightheadedness]], [[palpitations]], [[rash]], [[nausea]], [[dizziness]], [[headache]], [[dyspnea]], [[fatigue]]
| C=12 | H=20 | N=2 | O=3 | S=1
|blackBoxWarningTitle=WARNING
| molecular_weight = 272.3624 g/mol
|blackBoxWarningBody=<i><span style="color:#FF0000;">INDUCED ARRHYTHMIA:</span></i> To minimize the risk of induced arrhythmia, patients initiated or re-initiated on sotalol hydrochloride tablets (AF) should be placed for a minimum of three days (on their maintenance dose) in a facility that can provide cardiac resuscitation, continuous electrocardiographic monitoring and calculations of creatinine clearance. For detailed instructions regarding dose selection and special cautions for people with renal impairment. Sotalol is also indicated for the treatment of documented life-threatening ventricular arrhythmias and is marketed under the brand name Betapace (sotalol hydrochloride). Sotalol hydrochloride tablets, however, must not be substituted for Betapace AF (sotalol hydrochloride tablets, USP (AF)) because of significant differences in labeling (i.e. patient package insert, dosing administration and safety information).
| bioavailability = >95%
|fdaLIADAdult====Oral Tharapy===
| metabolism = Not metabolised
* Therapy with sotalol hydrochloride tablets (AF) must be initiated (and, if necessary, titrated) in a setting that provides continuous [[electrocardiographic]] (ECG) monitoring and in the presence of personnel trained in the management of serious [[ventricular arrhythmias]]. Patients should continue to be monitored in this way for a minimum of 3 days on the maintenance dose. In addition, patients should not be discharged within 12 hours of electrical or pharmacological conversion to normal [[sinus rhythm]].
| elimination_half-life = 12 hours
* The [[QT interval]] is used to determine patient eligibility for sotalol hydrochloride tablets (AF) treatment and for monitoring safety during treatment. The baseline [[QT interval]] must be ≤450 msec in order for a patient to be started on sotalol hydrochloride tablets (AF) therapy. During initiation and titration, the QT interval should be monitored 2 to 4 hours after each dose. If the QT interval prolongs to 500 msec or greater, the dose must be reduced or the drug discontinued.
| excretion = [[Kidney|Renal]] <br> [[Mammary gland|Lactic]] (In lactating females)
* The dose of sotalol hydrochloride tablets, USP (AF) must be individualized according to calculated [[creatinine clearance]]. In patients with a [[creatinine clearance]] >60 mL/min sotalol hydrochloride tablets (AF) are administered twice daily (BID) while in those with a [[creatinine clearance]] between 40 and 60 mL/min, the dose is administered once daily (QD) or half the dose is administered twice daily (BID). In patients with a [[creatinine clearance]] less than 40 mL/min sotalol hydrochloride tablets (AF) are contraindicated. The recommended initial dose of sotalol hydrochloride tablets (AF) is 80 mg and is initiated as shown in the dosing algorithm described below. The 80 mg dose can be titrated upward to 100 mg or 120 mg during initial hospitalization or after discharge on 80 mg in the event of recurrence, by rehospitalization and repeating the same steps used during the initiation of therapy.
| pregnancy_AU =
* Patients with atrial fibrillation should be anticoagulated according to usual medical practice. [[Hypokalemia]] should be corrected before initiation of sotalol hydrochloride tablets (AF) therapy.
* Patients to be discharged on sotalol hydrochloride tablets (AF) therapy from an in-patient setting should have an adequate supply of sotalol hydrochloride tablets (AF), to allow uninterrupted therapy until the patient can fill a sotalol hydrochloride tablets (AF) prescription.
 
=====Initiation of Sotalol Hydrochloride Tablets, USP (AF) Therapy=====
* '''Step 1.''' [[Electrocardiographic]] assessment: Prior to administration of the first dose, the [[QT interval]] must be determined using an average of 5 beats. If the baseline QT is greater than 450 msec (JT ≥330 msec if QRS over 100 msec), sotalol hydrochloride tablets (AF) are contraindicated.
* '''Step 2.''' Calculation of [[creatinine clearance]]: Prior to the administration of the first dose, the patient's [[creatinine clearance]] should be calculated using the following formula:
 
[[File:SotalolDosingFormula.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
When serum [[creatinine]] is given in μmol/L, divide the value by 88.4 (1 mg/dL = 88.4 mcmol/L).
 
* '''Step 3.''' Starting Dose: The starting dose of sotalol hydrochloride tablets (AF) is 80 mg twice daily (BID) if the [[creatinine clearance]] is >60 mL/min, and 80 mg once daily (QD) if the [[creatinine clearance]] is 40 to 60 mL/min. If the [[creatinine clearance]] is <40 mL/min sotalol hydrochloride tablets (AF) are contraindicated.
* '''Step 4.''' Administer the appropriate daily dose of sotalol hydrochloride tablets (AF) and begin continuous [[ECG]] monitoring with [[QT]] interval measurements 2 to 4 hours after each dose.
* '''Step 5.''' In patients with a [[creatinine clearance]] >60 mL/min, if the 80 mg dose level is tolerated and the [[QT interval]] remains <500 msec after at least 3 days (after 5 or 6 doses if patient receiving QD dosing), the patient can be discharged. Alternatively, during hospitalization, the dose can be increased to 100 mg or 120 mg BID and the patient followed for 3 days on this dose (followed for 5 or 6 doses if patient receiving QD doses).
 
'''''The steps described above are summarized in the following diagram:'''''
* Place Patient on [[Telemetry]]
* Check Baseline QT
* If QT >450 msec sotalol hydrochloride tablets (AF) are CONTRAINDICATED
* If QT ≤450 msec, proceed
* Calculate [[Creatine Clearance]] (Clcr)
* If Clcr is <40 mL/min sotalol hydrochloride tablets (AF) are CONTRAINDICATED
* If Clcr is 40-60 mL/min start sotalol hydrochloride tablets (AF) 80 mg QD
* If Clcr is >60 mL/min start sotalol hydrochloride tablets (AF) 80 mg BID
* Monitor QT 2 to 4 hours after each dose.
* If QT ≥500 msec discontinue sotalol hydrochloride tablets (AF)
* If QT <500 msec after 3 days (after 5th or 6th dose if patient receiving QD dosing) discharge patient on current treatment. Alternatively, during hospitalization, the dose can be increased to 120 mg BID and the patient followed for 3 days on this dose (followed for 5 or 6 doses if patient receiving QD doses).
 
=====Upward Titration of Dose=====
* If the 80 mg dose level (given BID or QD depending upon the [[creatinine clearance]]) does not reduce the frequency of relapses of [[AFIB]]/[[AFL]] and is tolerated without excessive [[QT interval]] prolongation (i.e., ≥520 msec), the dose level may be increased to 120 mg (BID or QD depending upon the [[creatinine clearance]]).  As proarrhythmic events can occur not only at initiation of therapy, but also with each upward dosage adjustment, Steps 2 through 5 used during initiation of sotalol hydrochloride tablet (AF) therapy should be followed when increasing the dose level. In the U.S. multicenter dose-response study, the 120 mg dose (BID or QD) was found to be the most effective in prolonging the time to [[ECG]] documented symptomatic recurrence of [[AFIB]]/[[AFL]]. If the 120 mg dose does not reduce the frequency of early relapse of [[AFIB]]/[[AFL]] and is tolerated without excessive [[QT interval]] prolongation (≥520 msec), an increase to 160 mg (BID or QD depending upon the [[creatinine clearance]]), can be considered. Steps 2 through 5 used during the initiation of therapy should be used again to introduce such an increase.
 
=====Maintenance of Sotalol Hydrochloride Tablets, USP (AF) Therapy=====
* Renal function and QT should be re-evaluated regularly if medically warranted. If QT is 520 msec or greater (JT 430 msec or greater if QRS is > 100 msec), the dose of sotalol hydrochloride tablets (AF) therapy should be reduced and patients should be carefully monitored until QT returns to less than 520 msec. If the QT interval is ≥520 msec while on the lowest maintenance dose level (80 mg) the drug should be discontinued. If renal function deteriorates, reduce the daily dose in half by administering the drug once daily as described in Initiation of sotalol hydrochloride tablets (AF) Therapy, Step 3.
 
=====Special Considerations=====
* The maximum recommended dose in patients with a [[calculated creatinine]] clearance greater than 60 mL/min is 160 mg BID, doses greater than 160 mg BID have been associated with an increased incidence of [[Torsade de Pointes]] and are not recommended.
 
* A patient who misses a dose should NOT double the next dose. The next dose should be taken at the usual time.
 
===IV Therapy===
=====General Rules and Safety Measures of Intravenous Sotalol Therapy=====
* For the safety of the patient, the safety measures required of oral sotalol administration must also be applied for intravenous route. To minimize the risk of induced [[arrhythmia]], patients initiated or re-initiated on sotalol should be hospitalized for at least three days or until steady state drug levels are achieved, in a facility that can provide cardiac resuscitation and continuous [[electrocardiographic]] monitoring. Initiate intravenous sotalol therapy in the presence of personnel trained in the management of serious [[ventricular arrhythmias]]. Perform a baseline [[ECG]] to determine the [[QT interval]] and measure and normalize serum [[potassium]] and [[magnesium]] levels before initiating therapy with starting sotalol injection. Measure serum [[creatinine]] and calculate an estimated [[creatinine clearance]] in order to establish the appropriate dosing interval for sotalol.
* If the baseline QT is greater than 450 ms (JT >330 ms if QRS over 100 ms), sotalol is not recommended.
* The patient's [[creatinine clearance]] should be calculated using the one of several formulas. The Cockcroft-Gault formula to determine creatinine clearance is:
 
[[File:SotalolDosingIVFormula1.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
* When serum [[creatinine]] is given in µmol/L, divide the value by 88.4 (1 mg/dL = 88.4 µmol/L).
* Start sotalol therapy only if the baseline [[QT interval]] is <450 ms. During initiation and titration, monitor the [[QT interval]] after the completion of each infusion If the [[QT interval]] prolongs to 500 ms or greater, reduce the dose, decrease the infusion rate, or discontinue the drug.
* Administer sotalol twice daily in patients with a [[creatinine clearance]] >60 mL/min or once daily) in patients with a [[creatinine clearance]] between 40 and 60 mL/min. Sotalol is not recommended in patients with a [[creatinine clearance]] <40 mL/min. The recommended initial IV dose of sotalol is 75 mg (once or twice daily) and is initiated as shown in the dosing algorithm described below. The 75 mg dose can be titrated upward to 112.5 or 150 mg after at least 3 days.
 
=====Dose of Intravenous Sotalol=====
* The bioavailability of oral sotalol is between 90% and 100%. The corresponding dose of intravenous sotalol is, therefore, slightly less than that of the oral dose. The effects of the initial intravenous dose must be monitored and the dose titrated either upward or downward, if needed, based on clinical effect, QT interval, or adverse reactions.
 
[[File:SotalolDosingIVFormula2.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
=====Preparation of Sotalol Infusion=====
* Intravenous sotalol must be diluted for infusion. Appropriate diluents are saline, 5% dextrose in water (D5W), or [[Ringer's lactate]]. Usually, prepare in a volume of 100-250 mL. Use a volumetric infusion pump to infuse intravenous sotalol at a constant rate. The following table compensates for dead space in the infusion set.
 
[[File:SotalolInfusionPreparationTable.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
=====Initiation of Intravenous Sotalol Therapy=====
* The starting dose of intravenous sotalol is 75 mg infused over 5 hours once or twice daily based on the [[creatinine clearance]]. Monitor [[ECG]] for excessive increase in QTc.
 
=====Upward Titration of Dose=====
* If the 75 mg dose of intravenous sotalol does not reduce the frequency of relapses of life threatening [[ventricular arrhythmias]] or symptomatic [[AFIB]]/[[AFL]] and is tolerated without excessive (i.e., to >500 ms) QTc prolongation, increase the dose to 112.5 mg infused over 5 hours, once or twice daily depending upon the [[creatinine clearance]]. Continue to monitor QTc during dose escalations.
 
=====Dose for Ventricular Arrhythmias=====
* The recommended initial dose of intravenous sotalol is 75 mg infused over 5 hours, once or twice daily based on [[creatinine clearance]]. The dose may be increased in increments of 75 mg/day every 3 days. The usual therapeutic effect is observed with oral doses of 80 to 160 mg once or twice a day (corresponding to 75 to 150 mg intravenous sotalol). Oral doses as high as 240-320 mg once or twice a day (corresponding to 225 to 300 mg intravenous sotalol) have been utilized in patients with refractory life-threatening [[arrhythmias]].
 
=====Dose for Symptomatic AFIB/AFL=====
* In the U.S. multicenter dose-response study, 120 mg orally once or twice a day (corresponding to 112.5 mg intravenous sotalol) was found to be the most effective dose in prolonging the time to [[ECG]]-documented symptomatic recurrence of [[AFIB]]/[[AFL]]. If that dose level, at steady state, does not reduce the frequency of early relapse of arrhythmia and is tolerated without excessive QTc prolongation (>520 ms), increase the dose to 160 mg orally once or twice a day (corresponding to 150 mg intravenous sotalol).
|offLabelAdultGuideSupport=There is limited information regarding <i>Off-Label Guideline-Supported Use</i> of Sotalol in adult patients.
|offLabelAdultNoGuideSupport======Angina Pectoris=====
 
* Dosing Information
 
:* 120 to 480 mg PO q24h.<ref name="pmid4157126">{{cite journal| author=Gooding PG, Berman E| title=An evaluation of sotalol, a beta-blocking agent, in patients with angina pectoris. | journal=Postgrad Med J | year= 1974 | volume= 50 | issue= 590 | pages= 734-6 | pmid=4157126 | doi= | pmc=PMC2496011 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4157126  }} </ref>
:* 20 mg IV as single dose.<ref name="pmid1233240">{{cite journal| author=Areskog NH, Cullhed I, Ringqvist I, Ström G| title=Cardiovascular and respiratory effects of the beta-adrenoceptive antagonist sotalol: studies in health, angina pectoris and obstructive lung disease. | journal=Eur J Clin Pharmacol | year= 1975 | volume= 8 | issue= 6 | pages= 403-8 | pmid=1233240 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1233240  }} </ref>
 
=====Hypertension=====
 
* Dosing Information
 
:* 80 to 320 mg PO q24h.<ref name="pmid489772">{{cite journal| author=Parvinen I, Paukkala E| title=Thrice-daily blood pressure readings on sotalol in the treatment of hypertension: once- versus twice-daily regimen. | journal=J Clin Pharmacol | year= 1979 | volume= 19 | issue= 8-9 Pt 2 | pages= 533-9 | pmid=489772 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=489772  }} </ref>
|fdaLIADPed====Oral Therapy===
* As in adults the following precautionary measures should be considered when initiating sotalol treatment in children: initiation of treatment in the hospital after appropriate clinical assessment; individualized regimen as appropriate; gradual increase of doses if required; careful assessment of therapeutic response and tolerability; and frequent monitoring of the [[QTc interval]] and heart rate.
 
=====For children aged about 2 years and greater=====
* For children aged about 2 years and greater, with normal renal function, doses normalized for body surface area are appropriate for both initial and incremental dosing. Since the Class III potency in children is not very different from that in adults, reaching plasma concentrations that occur within the adult dose range is an appropriate guide. From pediatric pharmacokinetic data the following is recommended.
 
* For initiation of treatment, 30 mg/m2 three times a day (90 mg/m2 total daily dose) is approximately equivalent to the initial 160 mg total daily dose for adults. Subsequent titration to a maximum of 60 mg/m2 (approximately equivalent to the 360 mg total daily dose for adults) can then occur. Titration should be guided by clinical response, heart rate and QTc, with increased dosing being preferably carried out in-hospital. At least 36 hours should be allowed between dose increments to attain steady-state plasma concentrations of sotalol in patients with age-adjusted normal renal function.
 
=====For children aged about 2 years or younger=====
* For children aged about 2 years or younger the above pediatric dosage should be reduced by a factor that depends heavily upon age, as shown in the following graph, age plotted on a logarithmic scale in months.
 
[[File:SotalolFigure3.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
* For a child aged 20 months, the dosing suggested for children with normal renal function aged 2 years or greater should be multiplied by about 0.97; the initial starting dose would be (30 X 0.97)=29.1 mg/m2, administered three times daily. For a child aged 1 month, the starting dose should be multiplied by 0.68; the initial starting dose would be (30 X 0.68)=20 mg/m2, administered three times daily. For a child aged about 1 week, the initial starting dose should be multiplied by 0.3; the starting dose would be (30 X 0.3)=9 mg/m2. Similar calculations should be made for increased doses as titration proceeds. Since the half-life of sotalol decreases with decreasing age (below about 2 years), time to steady-state will also increase. Thus, in neonates the time to steady-state may be as long as a week or longer.
 
* In all children, individualization of dosage is required. As in adults sotalol hydrochloride tablets (AF) should be used with particular caution in children if the QTc is greater than 500 msec on therapy and serious consideration should be given to reducing the dose or discontinuing therapy when QTc exceeds 550 msec.
 
The use of sotalol hydrochloride tablets (AF) in children with [[renal impairment]] has not been investigated. Sotalol elimination is predominantly via the [[kidney]] in the unchanged form. Use of sotalol in any age group with decreased [[renal function]] should be at lower doses or at increased intervals between doses. Monitoring of heart rate and QTc is more important and it will take much longer to reach steady-state with any dose and/or frequency of administration.
 
=====Transfer to Sotalol Hydrochloride Tablets (AF) from Sotalol Hydrochloride Tablets=====
* Patients with a history of symptomatic [[AFIB]]/[[AFL]] who are currently receiving sotalol hydrochloride for the maintenance of normal sinus should be transferred to sotalol hydrochloride tablets (AF) because of the significant differences in labeling (i.e., patient package insert, dosing administration, and safety information).
 
=====Transfer to Sotalol Hydrochloride Tablets (AF) from Other Antiarrhythmic Agents=====
* Before starting sotalol hydrochloride tablets (AF), previous [[antiarrhythmic]] therapy should generally be withdrawn under careful monitoring for a minimum of 2 to 3 plasma half-lives if the patient's clinical condition permits. Treatment has been initiated in some patients receiving I.V. [[lidocaine]] without ill effect. After discontinuation of [[amiodarone]], sotalol hydrochloride tablets (AF) should not be initiated until the QT interval is normalized.
 
'''Preparation of Extemporaneous Oral Solution'''
* Sotalol hydrochloride (AF) Syrup 5 mg/mL can be compounded using Simple Syrup containing 0.1% sodium benzoate (Syrup, NF) available from Humco Laboratories as follows:
# Measure 120 mL of Simple Syrup
# Transfer the syrup to a 6-ounce amber plastic (polyethylene terephthalate [PET]) prescription bottle. NOTE: An oversized bottle is used to allow for a headspace, so that there will be more effective mixing during shaking of the bottle.
# Add five (5) sotalol hydrochloride (AF) 120 mg tablets to the bottle. These tablets are added intact; it is not necessary to crush the tablets. NOTE: The addition of the tablets can also be done first. The tablets can also be crushed if preferred. If the tablets are crushed, care should be taken to transfer the entire quantity of tablet powder into the bottle containing the syrup.
# Shake the bottle to wet the entire surface of the tablets. If the tablets have been crushed, shake the bottle until the endpoint is achieved.
# Allow the tablets to hydrate for approximately two hours.
# After at least two hours have elapsed, shake the bottle intermittently over the course of at least another two hours until the tablets are completely disintegrated. NOTE: The tablets can be allowed to hydrate overnight to simplify the disintegration process.
 
* The endpoint is achieved when a dispersion of fine particles in the syrup is obtained.
 
* This compounding procedure results in a solution containing 5 mg/mL of sotalol HCl. The fine solid particles are the water-insoluble inactive ingredients of the tablets.
 
* This extemporaneously prepared oral solution of sotalol HCl (with suspended inactive particles) must be shaken well prior to administration. This is to ensure that the amount of inactive solid particles per dose remains constant throughout the duration of use.
 
* Stability studies indicate that the suspension is stable when stored at controlled room temperature (15° to 30°C/59° to 86°F) and ambient humidity for three (3) months.
 
===IV Therapy===
* Intravenous sotalol has not been studied in children. As in adults the following precautionary measures should be considered when initiating sotalol treatment in children: initiation of treatment in the hospital after appropriate clinical assessment; individualized regimen as appropriate; gradual increase of doses if required; careful assessment of therapeutic response and tolerability; and frequent monitoring of the [[QTc interval]] and heart rate.
 
=====For children aged about 2 years and greater=====
* For children aged about 2 years and greater, with normal [[renal function]], doses normalized for body surface area are appropriate for both initial and incremental dosing. Since the Class III potency in children is not very different from that in adults, reaching plasma concentrations that occur within the adult dose range is an appropriate guide. From pediatric pharmacokinetic data the following is recommended. For initiation of treatment, 30 mg/m2 three times a day (90 mg/m2 total daily dose) is approximately equivalent to the initial 160 mg total oral daily dose for adults. Subsequent titration to a maximum of 60 mg/m2 (approximately equivalent to the 360 mg total daily dose for adults) can then occur. Titration should be guided by clinical response, heart rate and QTc, with increased dosing being carried out in-hospital. At least 36 hours should be allowed between dose increments to attain steady-state plasma concentrations of sotalol in patients with age-adjusted normal [[renal function]].
 
=====For children aged about 2 years or younger=====
* For children about 2 years or younger the above pediatric dosage should be reduced by a factor that depends heavily upon age, as shown in the following graph which shows age plotted on a logarithmic scale in months.
 
[[File:SotalolFigure3.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
* For a child aged 20 months, the dosing suggested for children with normal renal function aged 2 years or greater should be multiplied by about 0.97; the initial starting dose would be (30 × 0.97) = 29.1 mg/m2, administered orally three times daily. For a child aged 1 month, the starting dose should be multiplied by 0.68; the initial starting dose would be (30 × 0.68) = 20 mg/m2, administered orally three times daily. For a child aged 1 week, the initial starting oral dose should be multiplied by 0.3; the starting dose would be (30 × 0.3) = 9 mg/m2. Similar calculations should be made for increased doses as titration proceeds. Since the half-life of sotalol decreases with decreasing age (below about 2 years), time to steady-state will also increase. Thus, in neonates the time to steady-state may be as long as a week or longer.
 
* In all children, individualization of dosage is required. As in adults sotalol should be used with particular caution in children if the QTc is greater than 500 ms on therapy and serious consideration should be given to reducing the dose or discontinuing therapy when QTc exceeds 550 ms.
 
* The use of oral sotalol in children with renal impairment has not been investigated. Sotalol elimination is predominantly via the [[kidney]] in the unchanged form. Use of sotalol in any age group with decreased renal function should be at lower doses or at increased intervals between doses. Monitoring of heart rate and QTc is most important. It will take much longer to reach steady-state with any dose and/or frequency of administration in these children.
|offLabelPedGuideSupport=There is limited information regarding <i>Off-Label Guideline-Supported Use</i> of Sotalol in pediatric patients.
|offLabelPedNoGuideSupport=There is limited information regarding <i>Off-Label Non–Guideline-Supported Use</i> of Sotalol in pediatric patients.
|contraindications=* [[Bronchial asthma]].
* [[Sinus bradycardia]].
* [[Second degree AV block]] and [[third degree AV block]], unless a functioning pacemaker is present.
* Congenital or acquired [[long QT syndromes]].
* [[Cardiogenic shock]].
* Uncontrolled [[congestive heart failure]].
* [[Hypersensitivity]] to Betapace.
|warnings======Ventricular Arrhythmia=====
* Sotalol (AF) can cause serious [[ventricular arrhythmias]], primarily [[Torsade de Pointes]] (TdP) type [[ventricular tachycardia]], a [[polymorphic ventricular tachycardia]] associated with [[QT interval prolongation]]. [[QT interval prolongation]] is directly related to the dose of sotalol (AF). Factors such as reduced [[creatinine clearance]], gender (female) and larger doses increase the risk of TdP. The risk of TdP can be reduced by adjustment of the sotalol (AF) dose according to [[creatinine clearance]] and by monitoring the ECG for excessive increases in the [[QT interval]].
 
* Treatment with sotalol (AF) must therefore be started only in patients observed for a minimum of three days on their maintenance dose in a facility that can provide electrocardiographic monitoring and in the presence of personnel trained in the management of serious [[ventricular arrhythmias]]. Calculation of the creatinine clearance must precede administration of the first dose of sotalol (AF). For detailed instructions regarding dose selection.
 
=====Proarrhythmia in Atrial Fibrillation/Atrial Flutter Patients=====
* In eight controlled trials of patients with [[AFIB]]/[[AFL]] and other [[supraventricular arrhythmias]] (N=659) there were four cases of [[Torsade de Pointes reported]] (0.6%) during the controlled phase of treatment with sotalol (AF). The incidence of [[Torsade de Pointes]] was significantly lower in those patients receiving total daily doses of 320 mg or less (0.3%), as summarized in Table 5 below. Both patients who had [[Torsade de Pointes]] in the group receiving >320 mg/day were receiving 640 mg/day. In the group receiving ≤320 mg daily, one case of TdP occurred at a daily dose of 320 mg on day 4 of treatment and one case occurred on a daily dose of 160 mg on day 1 of treatment.
 
[[File:SotalolTable6.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
* The table below relates the incidence of [[Torsade de Pointes]] to on-therapy QTc and change in QTc from baseline. It should be noted, however, that the highest on therapy QTc was in many cases the one obtained at the time of the [[Torsade de Pointes]] event, so that the table overstates the predictive value of a high QTc.
 
[[File:SotalolTable7.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
* In addition to dose and presence of sustained [[VT]], other risk factors for [[Torsade de Pointes]] were gender (females had a higher incidence), excessive prolongation of the [[QTc interval]] and history of [[cardiomegaly]] or [[congestive heart failure]]. Patients with sustained [[ventricular tachycardia]] and a history of [[congestive heart failure]] appear to have the highest risk for serious proarrhythmia (7%). Of the [[ventricular arrhythmia]] patients experiencing [[Torsade de Pointes]], approximately two-thirds spontaneously reverted to their baseline rhythm. The others were either converted electrically (D/C cardioversion or overdrive pacing) or treated with other drugs. It is not possible to determine whether some sudden deaths represented episodes of [[Torsade de Pointes]], but in some instances sudden death did follow a documented episode of [[Torsade de Pointes]]. Although sotalol therapy was discontinued in most patients experiencing [[Torsade de Pointes]], 17% were continued on a lower dose.
 
=====Use with Drugs that Prolong QT Interval and Antiarrhythmic Agents=====
* The use of sotalo (AF) in conjunction with other drugs that prolong the QT interval has not been studied and is not recommended. Such drugs include many [[antiarrhythmics]], some [[phenothiazines]], bepridil, [[tricyclic antidepressants]], and certain oral [[macrolides]]. Class I or Class III [[antiarrhythmic agents]] should be withheld for at least three half-lives prior to dosing with sotalol (AF). In clinical trials, sotalots (AF) was not administered to patients previously treated with oral [[amiodarone]] for >1 month in the previous three months. Class Ia [[antiarrhythmic]] drugs, such as [[disopyramide]], [[quinidine]] and [[procainamide]] and other Class III drugs (e.g., amiodarone) are not recommended as concomitant therapy with sotalots (AF), because of their potential to prolong refractoriness. There is only limited experience with the concomitant use of Class Ib or Ic [[antiarrhythmics]].
 
=====Congestive Heart Failure=====
* Sympathetic stimulation is necessary in supporting circulatory function in [[congestive heart failure]], and [[beta-block]]ade carries the potential hazard of further depressing [[myocardial contractility]] and precipitating more severe failure. In patients who have [[heart failure]] controlled by [[digitalis]] and/or [[diuretics]], sotalol (AF) should be administered cautiously. Both digitalis and sotalol slow [[AV conduction]]. As with all [[beta-blockers]], caution is advised when initiating therapy in patients with any evidence of left ventricular dysfunction. In a pooled data base of four placebo-controlled [[AFIB]]/[[AFL]] and [[PSVT]] studies, new or worsening CHF occurred during therapy with sotalol (AF) in 5 (1.2%) of 415 patients. In these studies patients with uncontrolled heart failure were excluded (i.e., NYHA Functional Classes III or IV). In other premarketing sotalol studies, new or worsened [[congestive heart failure]] (CHF) occurred in 3.3% (n=3257) of patients and led to discontinuation in approximately 1% of patients receiving sotalol. The incidence was higher in patients presenting with [[sustained ventricular tachycardia]]/[[ventricular fibrillation]] (4.6%, n=1363), or a prior history of [[heart failure]] (7.3%, n=696). Based on a life-table analysis, the one-year incidence of new or worsened CHF was 3% in patients without a prior history and 10% in patients with a prior history of CHF. NYHA Classification was also closely associated to the incidence of new or worsened [[heart failure]] while receiving sotalol (1.8% in 1395 Class I patients, 4.9% in 1254 Class II patients and 6.1% in 278 Class III or IV patients).
 
=====Electrolyte Disturbances=====
* Sotalol (AF) should not be used in patients with [[hypokalemia]] or [[hypomagnesemia]] prior to correction of imbalance, as these conditions can exaggerate the degree of [[QT prolongation]], and increase the potential for [[Torsade de Pointes]]. Special attention should be given to electrolyte and acid-base balance in patients experiencing severe or prolonged [[diarrhea]] or patients receiving concomitant diuretic drugs.
 
=====Bradycardia/Heart Block=====
* The incidence of [[bradycardia]] (as determined by the investigators) in the supraventricular [[arrhythmia]] population treated with sotalol (AF) (N = 415) was 13%, and led to discontinuation in 2.4% of patients. [[Bradycardia]] itself increases the risk of [[Torsade de Pointes]].
 
=====Recent Acute MI=====
* Sotalol has been used in a controlled trial following an [[acute myocardial infarction]] without evidence of increased mortality (see Safety in Patients with Structural Heart Disease). Although specific studies of its use in treating atrial arrhythmias after infarction have not been conducted, the usual precautions regarding heart failure, avoidance of [[hypokalemia]], [[bradycardia]] or prolonged [[QT interval]] apply.
 
=====Warnings related to the beta-blocking activity of sotalol AF=====
======Abrupt Withdrawal======
* [[Hypersensitivity]] to [[catecholamines]] has been observed in patients withdrawn from [[beta-blocker]] therapy. Occasional cases of exacerbation of [[angina pectoris]], [[arrhythmias]] and, in some cases, [[myocardial infarction]] have been reported after abrupt discontinuation of [[beta-blocker]] therapy. Therefore, it is prudent when discontinuing chronically administered sotalol (AF), particularly in patients with [[ischemic heart disease]], to carefully monitor the patient and consider the temporary use of an alternate [[beta-blocker]] if appropriate. If possible, the dosage of sotalol (AF) should be gradually reduced over a period of one to two weeks. If [[angina]] or [[acute coronary insufficiency]] develops, appropriate therapy should be instituted promptly. Patients should be warned against interruption or discontinuation of therapy without the physician's advice. Because coronary artery disease is common and may be unrecognized in patients receiving sotalols (AF), abrupt discontinuation in patients with [[arrhythmias]] may unmask latent [[coronary insufficiency]].
 
======Non-Allergic Bronchospasm (e.g., chronic bronchitis and emphysema)======
* PATIENTS WITH [[BRONCHOSPASTIC DISEASES]] SHOULD IN GENERAL NOT RECEIVE [[BETA-BLOCKERS]]. It is prudent, if sotalol hydrochloride (AF) is to be administered, to use the smallest effective dose, so that inhibition of bronchodilation produced by endogenous or exogenous catecholamine stimulation of beta2 receptors may be minimized.
 
======Anaphylaxis======
* While taking [[beta-blockers]], patients with a history of [[anaphylactic]] reaction to a variety of [[allergens]] may have a more severe reaction on repeated challenge, either accidental, diagnostic or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat the [[allergic reaction]].
 
======Major Surgery======
* Chronically administered [[Beta blocker|beta-blocking]] therapy should not be routinely withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures.
 
======Diabetes======
* In patients with [[diabetes]] (especially labile diabetes) or with a history of episodes of spontaneous [[hypoglycemia]], sotalol (AF) should be given with caution since [[Beta blocker|beta-blockade]] may mask some important premonitory signs of acute [[hypoglycemia]]; e.g., [[tachycardia]].
 
======Sick Sinus Syndrome======
* Sotalol (AF) should be used only with extreme caution in patients with [[sick sinus syndrome]] associated with symptomatic [[arrhythmias]], because it may cause [[sinus bradycardia]], sinus pauses or sinus arrest. In patients with [[AFIB]] and sinus node dysfunction, the risk of [[Torsade de Pointes]] with sotalol (AF) therapy is increased, especially after [[cardioversion]]. [[Bradycardia]] following cardioversion in these patients is associated with QTc interval prolongation which is augmented due to the reverse use dependence of the Class III effects of sotalol (AF). Patients with [[AFIB]]/[[AFL]] associated with the sick sinus syndrome may be treated with sotalol (AF) if they have an implanted pacemaker for control of [[bradycardia]] symptoms.
 
======Thyrotoxicosis======
* [[Beta-block]]ade may mask certain clinical signs (e.g., [[tachycardia]]) of [[hyperthyroidism]]. Patients suspected of developing [[thyrotoxicosis]] should be managed carefully to avoid abrupt withdrawal of [[beta-block]]ade which might be followed by an exacerbation of symptoms of [[hyperthyroidism]], including [[thyroid storm]]. The [[beta-block]]ing effects of sotalol (AF) may be useful in controlling heart rate in [[AFIB]] associated with [[thyrotoxicosis]] but no study has been conducted to evaluate this.
|clinicalTrials=* Adverse events that are clearly related to sotalol AF are those which are typical of its Class II ([[Beta blocker|beta-blocking]]) and Class III (cardiac action potential duration prolongation) effects. The common documented beta-blocking adverse events ([[bradycardia]], [[dyspnea]], and [[fatigue]]) and Class III effects ([[QT interval]] prolongation) are dose related.
 
* In a pooled clinical trial population consisting of four placebo-controlled studies with 275 patients with [[AFIB]]/[[AFL]] treated with 160 to 320 mg doses of sotalol hydrochloride (AF), the following adverse events were reported at a rate of 2% or more in the 160-240 mg treated patients and greater than the rate in placebo patients (See Table 8). The data are presented by incidence of events in the sotalol (AF) and placebo groups by body system and daily dose. No significant irreversible non-cardiac end-organ toxicity was observed.
 
[[File:SotalolTable8.png|600px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
 
* Overall, discontinuation because of unacceptable adverse events was necessary in 17% of the patients, and occurred in 10% of patients less than two weeks after starting treatment. The most common adverse events leading to discontinuation of sotalol hydrochloride (AF) were: fatigue 4.6%, [[bradycardia]] 2.4%, [[proarrhythmia]] 2.2%, [[dyspnea]] 2%, and [[QT interval]] prolongation 1.4%.
 
* In clinical trials involving 1292 patients with sustained [[VT]]/[[VF]], the common adverse events (occurring in ≥2% of patients) were similar to those described for the [[AFIB]]/[[AFL]] population.
 
* Occasional reports of elevated serum [[liver enzymes]] have occurred with sotalol therapy but no cause and effect relationship has been established. One case of [[peripheral neuropathy]] which resolved on discontinuation of sotalol and recurred when the patient was rechallenged with the drug was reported in an early dose tolerance study. Elevated [[blood glucose]] levels and increased insulin requirements can occur in [[diabetic]] patients.
 
* In an unblinded multicenter trial of 25 patients with [[SVT]] and/or [[VT]] receiving daily doses of 30, 90 and 210 mg/m2 with dosing every 8 hours for a total of 9 doses, no [[Torsades de Pointes]] or other serious new [[arrhythmias]] were observed. One (1) patient, receiving 30 mg/m2 daily, was discontinued because of increased frequency of [[sinus pauses]]/[[bradycardia]]. Additional cardiovascular AEs were seen at the 90 and 210 mg/m2 daily dose levels. They included QT prolongations (2 patients), [[sinus pauses]]/[[bradycardia]] (1 patient), increased severity of atrial flutter and reported chest pain (1 patient). Values for QTc ≥525 msec were seen in 2 patients at the 210 mg/m2 daily dose level. Serious adverse events including death, [[Torsades de Pointes]], other proarrhythmias, high-degree [[AV blocks]] and [[bradycardia]] have been reported in infants and/or children.
 
=====Potential Adverse Effects=====
* Foreign marketing experience with sotalol hydrochloride shows an adverse experience profile similar to that described above from clinical trials. Voluntary reports since introduction also include rare reports of: [[emotional liability]], slightly clouded [[sensorium]], [[incoordination]], [[vertigo]], [[paralysis]], [[thrombocytopenia]], [[eosinophilia]], [[leukopenia]], photosensitivity reaction, [[fever]], [[pulmonary edema]], [[hyperlipidemia]], [[myalgia]], [[pruritis]], [[alopecia]].
 
* The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been associated with sotalol (AF) during investigational use and foreign marketing experience.
|drugInteractions=* '''''Drugs undergoing CYP450 metabolism:''''' Sotalol is primarily eliminated by renal excretion; therefore, drugs that are metabolized by [[CYP450]] are not expected to alter the pharmacokinetics of sotalol.
* '''''Digoxin:''''' Proarrhythmic events were more common in sotalol treated patients also receiving [[digoxin]]; it is not clear whether this represents an interaction or is related to the presence of [[CHF]], a known risk factor for [[proarrhythmia]], in the patients receiving [[digoxin]]. Both [[digitalis glycosides]] and [[beta-blockers]] slow [[atrioventricular conduction]] and decrease [[heart rate]]. Concomitant use can increase the risk of [[bradycardia]].
* '''''Calcium blocking drugs:''''' Sotalol (AF) should be administered with caution in conjunction with calcium blocking drugs because of possible additive effects on [[atrioventricular conduction]] or ventricular function. Additionally, concomitant use of these drugs may have additive effects on [[blood pressure]], possibly leading to [[hypotension]].
* '''''Catecholamine-depleting agents:''''' Concomitant use of catecholamine-depleting drugs, such as [[reserpine]] and [[guanethidine]], with a [[beta-blocker]] may produce an excessive reduction of resting sympathetic nervous tone. Patients treated with sotalol (AF) plus a [[catecholamine]] depletor should therefore be closely monitored for evidence of [[hypotension]] and/or marked [[bradycardia]] which may produce [[syncope]].
* '''''Insulin and oral antidiabetics:''''' [[Hyperglycemia]] may occur, and the dosage of [[insulin]] or [[antidiabetic drugs]] may require adjustment. Symptoms of [[hypoglycemia]] may be masked.
* '''''Beta-2-receptor stimulants:''''' [[Beta-agonists]] such as [[salbutamol]], [[terbutaline]] and [[isoprenaline]] may have to be administered in increased dosages when used concomitantly with sotalol (AF).
* '''''Clonidine:''''' [[Beta-block]]ing drugs may potentiate the rebound [[hypertension]] sometimes observed after discontinuation of [[clonidine]]; therefore, caution is advised when discontinuing [[clonidine]] in patients receiving sotalol (AF).
* '''''Other:''''' No pharmacokinetic interactions were observed with [[hydrochlorothiazide]] or [[warfarin]].
* '''''Antacids:''''' Administration of sotalol (AF) within 2 hours of antacids containing aluminum oxide and magnesium hydroxide should be avoided because it may result in a reduction in [[Cmax]] and [[AUC]] of 26% and 20%, respectively and consequently in a 25% reduction in the bradycardic effect at rest. Administration of the antacid two hours after sotalol (AF) has no effect on the pharmacokinetics or pharmacodynamics of sotalol.
* '''''Drug/Laboratory Test Interactions:''''' The presence of sotalol in the urine may result in falsely elevated levels of urinary [[metanephrine]] when measured by fluorimetric or photometric methods. In screening patients suspected of having a [[pheochromocytoma]] and being treated with sotalol, a specific method, such as a high performance liquid chromatographic assay with solid phase extraction (e.g., J. Chromatogr. 385:241, 1987) should be employed in determining levels of catecholamines.
|FDAPregCat=B
|useInPregnancyFDA=* Reproduction studies in rats and rabbits during organogenesis at 100 and 22 times the MRHD as mg/kg (9 and 7 times the MRHD as mg/m2), respectively, did not reveal any teratogenic potential associated with sotalol HCl. In rabbits, a high dose of sotalol HCl (160 mg/kg/day) at 16 times the MRHD as mg/kg (6 times the MRHD as mg/m2) produced a slight increase in fetal death likely due to maternal toxicity. Eight times the maximum dose (80 mg/kg/day or 3 times the MRHD as mg/m2) did not result in an increased incidence of fetal deaths. In rats, 1000 mg/kg/day sotalol HCl, 100 times the MRHD (18 times the MRHD as mg/m2), increased the number of early resorptions, while at 14 times the maximum dose (2.5 times the MRHD as mg/m2), no increase in early resorptions was noted. However, animal reproduction studies are not always predictive of human response.
 
* Although there are no adequate and well-controlled studies in pregnant women, sotalol HCl has been shown to cross the placenta, and is found in amniotic fluid. There has been a report of subnormal birth weight with sotalol. Therefore, sotalol (AF) should be used during pregnancy only if the potential benefit outweighs the potential risk.
|useInNursing=* Sotalol is excreted in the milk of laboratory animals and has been reported to be present in human milk. Because of the potential for adverse reactions in nursing infants from sotalol (AF), a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
|useInPed=* The safety and effectiveness of sotalol (AF) in children have not been established. However, the Class III electrophysiologic and beta-blocking effects, the pharmacokinetics, and the relationship between the effects ([[QTc interval]] and resting [[heart rate]]) and drug concentrations have been evaluated in children aged between 3 days and 12 years old.
|useInRenalImpair=* Sotalol hydrochloride (AF) is eliminated principally via the kidneys through glomerular filtration and to a small degree by tubular secretion. There is a direct relationship between renal function, as measured by serum [[creatinine]] or [[creatinine clearance]], and the elimination rate of sotalol hydrochloride (AF).
|administration=Oral/Intravenous
|monitoring======Ventricular Arrhythmias=====
 
* Administer the appropriate daily dose of sotalol hydrochloride tablets (AF) and begin continuous [[ECG]] monitoring with [[QT]] interval measurements 2 to 4 hours after each dose.
|overdose=Intentional or accidental overdosage with sotalol has rarely resulted in death.
 
=====Symptoms and Treatment of Overdosage=====
* The most common signs to be expected are [[bradycardia]], [[congestive heart failure]], [[hypotension]], [[bronchospasm]] and [[hypoglycemia]]. In cases of massive intentional overdosage (2 to 16 grams) of sotalol the following clinical findings were seen: [[hypotension]], [[bradycardia]], cardiac [[asystole]], prolongation of [[QT interval]], [[Torsade de Pointes]], [[ventricular tachycardia]], and [[premature ventricular complexes]]. If overdosage occurs, therapy with sotalol (AF) should be discontinued and the patient observed closely. Because of the lack of protein binding, [[hemodialysis]] is useful for reducing sotalol plasma concentrations. Patients should be carefully observed until [[QT intervals]] are normalized and the [[heart rate]] returns to levels >50 bpm. The occurrence of [[hypotension]] following an overdose may be associated with an initial slow drug elimination phase (half life of 30 hours) thought to be due to a temporary reduction of renal function caused by the [[hypotension]]. In addition, if required, the following therapeutic measures are suggested:
* '''''Bradycardia or Cardiac Asystole:''''' [[Atropine]], another [[anticholinergic]] drug, a [[beta-agonist]] or transvenous cardiac pacing.
* '''''Heart Block:''''' [[Second degree AV block]] and [[third degree AV block]] transvenous cardiac pacemaker.
* '''''Hypotension:''''' (depending on associated factors) [[epinephrine]] rather than [[isoproterenol]] or [[norepinephrine]] may be useful.
* '''''Bronchospasm:''''' [[Aminophylline]] or aerosol [[beta2-stimulant]].
* '''''Torsade de Pointes:''''' DC [[cardioversion]], transvenous cardiac pacing, [[epinephrine]], [[magnesium sulfate]].
|drugBox={{Drugbox2
| verifiedrevid = 420038718
| IUPAC_name = (''RS'')-''N''-{4-[1-hydroxy-2-(propan-2-ylamino)ethyl]phenyl}methanesulfonamide
| image = SotalolStructure.png
| imagename = 1 : 1 mixture (racemate)
| drug_name = Sotalol
 
<!--Clinical data-->
| tradename = Betapace
| Drugs.com = {{drugs.com|monograph|sotalol-hydrochloride}}
| MedlinePlus = a693010
| pregnancy_AU =  
| pregnancy_US = B
| pregnancy_US = B
| pregnancy_category =
| pregnancy_category =  
| legal_status = Rx-only
| legal_status = Rx-only
| routes_of_administration = oral
| routes_of_administration = oral
}}
__NOTOC__
{{CMG}}


'''''For patient information about Sotalol, click [[Sotalol (patient information)|here]].'''''
<!--Pharmacokinetic data-->
| bioavailability = >95%
| metabolism = Not metabolized{{Citation needed|date=May 2010}}
| elimination_half-life = 12 hours
| excretion = [[Kidney|Renal]] <br />[[Mammary gland|Lactic]] (In lactating females)


{{SB}} BETAPACE, SOTALOL HYDROCHLORIDE
<!--Identifiers-->
| CASNo_Ref = {{cascite|correct|CAS}}
| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 3930-20-9
| ATC_prefix = C07
| ATC_suffix = AA07
| PubChem = 5253
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB00489
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 5063
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = A6D97U294I
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D08525
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 471


==Overview==
<!--Chemical data-->
| C=12 | H=20 | N=2 | O=3 | S=1
| molecular_weight = 272.3624 g/mol
| smiles = O=S(=O)(Nc1ccc(cc1)C(O)CNC(C)C)C
| InChI = 1/C12H20N2O3S/c1-9(2)13-8-12(15)10-4-6-11(7-5-10)14-18(3,16)17/h4-7,9,12-15H,8H2,1-3H3
| InChIKey = ZBMZVLHSJCTVON-UHFFFAOYAR
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C12H20N2O3S/c1-9(2)13-8-12(15)10-4-6-11(7-5-10)14-18(3,16)17/h4-7,9,12-15H,8H2,1-3H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = ZBMZVLHSJCTVON-UHFFFAOYSA-N
}}
|mechAction=* Sotalol hydrochloride has both [[beta-blocker]] (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) [[antiarrhythmic]] properties. Sotalol hydrochloride is a racemic mixture of d- and l-sotalol. Both isomers have similar [[Class III antiarrhythmic]] effects, while the l-isomer is responsible for virtually all of the [[Beta blocker|beta-blocking]] activity. The [[Beta blocker|beta-blocking]] effect of sotalol is non-cardioselective, half maximal at about 80 mg/day and maximal at doses between 320 and 640 mg/day. Sotalol does not have partial agonist or membrane stabilizing activity. Although significant [[Beta blocker|beta-blockade]] occurs at oral doses as low as 25 mg, significant Class III effects are seen only at daily doses of 160 mg and above.


'''Sotalol''' (trade names '''Betapace''' and '''Betapace AF''', [[Berlex Laboratories]]) is a [[medication|drug]] used in individuals with rhythm disturbances ([[cardiac arrhythmia]]s) of the [[heart]], and to treat [[hypertension]] in some individuals.
* In children, a Class III electrophysiologic effect can be seen at daily doses of 210 mg/m2 body surface area (BSA). A reduction of the resting heart rate due to the beta-blocking effect of sotalol is observed at daily doses ≥ 90 mg/m2 in children.
|structure=* Sotalol hydrochloride is an [[antiarrhythmic]] drug with Class II ([[beta-blocker]]) and Class III (cardiac action potential duration prolongation) properties. It is supplied as a light-blue, capsule-shaped tablet for oral administration. Sotalol hydrochloride is a white, crystalline solid with a molecular weight of 308.8. It is hydrophilic, soluble in water, propylene glycol and ethanol, but is only slightly soluble in chloroform. Chemically, sotalol hydrochloride is d,l-N -[4-[1-hydroxy-2-[(1-methylethyl) amino]ethyl]phenyl]methane-sulfonamide monohydrochloride. The molecular formula is C12H20N2O3 S·HCl and is represented by the following structural formula:


==Category==
[[File:SotalolStructure.png|600px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}


Beta Blockers
* Satolol tablets contain the following inactive ingredients: microcrystalline cellulose, lactose, starch, stearic acid, magnesium stearate, colloidal silicon dioxide, and FD&C blue color #2 (aluminum lake, conc.).
|PD=* Sotalol hydrochloride prolongs the plateau phase of the cardiac action potential in the isolated myocyte, as well as in isolated tissue preparations of ventricular or atrial muscle (Class III activity). In intact animals it slows [[heart rate]], decreases [[AV nodal conduction]] and increases the refractory periods of atrial and ventricular muscle and conduction tissue.


==FDA Package Insert==
* In man, the Class II ([[beta-block]]ade) electrophysiological effects of sotalol are manifested by increased sinus cycle length (slowed [[heart rate]]]), decreased [[AV nodal conduction]] and increased AV nodal refractoriness. The Class III electrophysiological effects in man include prolongation of the atrial and ventricular monophasic action potentials, and effective refractory period prolongation of atrial muscle, ventricular muscle, and atrio-ventricular [[accessory pathways]] (where present) in both the anterograde and retrograde directions. With oral doses of 160 to 640 mg/day, the surface [[ECG]] shows dose-related mean increases of 40-100 msec in QT and 10-40 msec in QTc. No significant alteration in [[QRS]] interval is observed.


====BETAPACE (sotalol hydrochloride) tablet====
* In a small study (n=25) of patients with implanted defibrillators treated concurrently with sotalol, the average defibrillatory threshold was 6 joules (range 2-15 joules) compared to a mean of 16 joules for a nonrandomized comparative group primarily receiving [[amiodarone]].


'''  [[Sotalol tablet indications and usage|Indications and Usage]]'''
* Twenty-five children in an unblinded, multicenter trial with [[supraventricular tachycardias]] ([[SVT]]) and/or [[ventricular tachyarrhythmias]] ([[VT]]), aged between 3 days and 12 years (mostly neonates and infants), received an ascending titration regimen with daily doses of 30, 90 and 210 mg/m2 with dosing every 8 hours for a total 9 doses. During steady-state, the respective average increases above baseline of the [[QTc interval]], in msec (%), were 2(+1%), 14(+4%) and 29(+7%) msec at the 3 dose levels. The respective mean maximum increases above baseline of the [[QTc interval]], in msec (%), were 23(+6%), 36(+9%) and 55(+14%) msec at the 3 dose levels. The steadystate percent increases in the RR interval were 3, 9 and 12%. The smallest children (BSA<0.33m2) showed a tendency for larger Class III effects (ΔQTc) and an increased frequency of prolongations of the QTc interval as compared with larger children (BSA≥0.33m2). The [[beta-block]]ing effects also tended to be greater in the smaller children (BSA<0.33m2). Both the Class III and [[Beta blocker|beta-blocking]] effects of sotalol were linearly related with the plasma concentrations.
'''| [[Sotalol tablet dosage and administration|Dosage and Administration]]'''
|PK=* In healthy subjects, the oral bioavailability of sotalol hydrochloride is 90-100%. After oral administration, peak plasma concentrations are reached in 2.5 to 4 hours, and steady-state plasma concentrations are attained within 2-3 days (i.e., after 5-6 doses when administered twice daily). Over the dosage range 160-640 mg/day sotalol hydrochloride displays dose proportionality with respect to plasma concentrations. Distribution occurs to a central (plasma) and to a peripheral compartment, with a mean elimination half-life of 12 hours. Dosing every 12 hours results in trough plasma concentrations which are approximately one-half of those at peak.
'''| [[Sotalol tablet contraindications|Contraindications]]'''
'''| [[Sotalol tablet warnings and precautions|Warnings and Precautions]]'''
'''| [[Sotalol tablet adverse reactions|Adverse Reactions]]'''
'''| [[Sotalol tablet drug interactions|Drug Interactions]]'''
'''| [[Sotalol tablet use in specific populations|Use in Specific Populations]]'''
'''| [[Sotalol tablet overdosage|Overdosage]]'''
'''| [[Sotalol tablet description|Description]]'''
'''| [[Sotalol tablet clinical pharmacology|Clinical Pharmacology]]'''
'''| [[Sotalol tablet clinical studies|Clinical Studies]]'''
'''| [[Sotalol tablet how supplied storage and handling|How Supplied/Storage and Handling]]'''
'''| [[Sotalol tablet labels and packages|Labels and Packages]]'''


{|
* Sotalol hydrochloride does not bind to plasma proteins and is not metabolized. Sotalol hydrochloride shows very little intersubject variability in plasma levels. The pharmacokinetics of the d and l enantiomers of sotalol are essentially identical. Sotalol hydrochloride crosses the blood brain barrier poorly. Excretion is predominantly via the [[kidney]] in the unchanged form, and therefore lower doses are necessary in conditions of [[renal impairment]]. Age per se does not significantly alter the pharmacokinetics of sotalol, but impaired [[renal function]] in geriatric patients can increase the terminal elimination half-life, resulting in increased drug accumulation. The absorption of sotalol hydrochloride was reduced by approximately 20% compared to fasting when it was administered with a standard meal. Since sotalol hydrochloride is not subject to first-pass metabolism, patients with [[hepatic impairment]] show no alteration in clearance of sotalol.
| [[File:Sotabb1.png|thumb|800px]]
|}


====SOTALOL HYDROCHLORIDE injection====
* The combined analysis of two unblinded, multicenter trials (a single dose and a multiple dose study) with 59 children, aged between 3 days and 12 years, showed the pharmacokinetics of sotalol to be first order. A daily dose of 30 mg/m2 of sotalol was administered in the single dose study and daily doses of 30, 90 and 210 mg/m2 were administered q 8h in the multi-dose study. After rapid absorption with peak levels occurring on average between 2-3 hours following administration, sotalol was eliminated with a mean half life of 9.5 hours. Steady-state was reached after 1-2 days. The average peak to trough concentration ratio was 2. BSA was the most important covariate and more relevant than age for the pharmacokinetics of sotalol.The smallest children (BSA<0.33m2) exhibited a greater drug exposure (+59%) than the larger children who showed a uniform drug concentration profile. The intersubject variation for oral clearance was 22%.
|nonClinToxic=* No evidence of carcinogenic potential was observed in rats during a 24-month study at 137-275 mg/kg/day (approximately 30 times the maximum recommended human oral dose (MRHD) as mg/kg or 5 times the MRHD as mg/m2) or in mice, during a 24-month study at 4141-7122 mg/kg/ day (approximately 450-750 times the MRHD as mg/kg or 36-63 times the MRHD as mg/m2).


'''  [[Sotalol injection indications and usage|Indications and Usage]]'''
* Sotalol has not been evaluated in any specific assay of [[mutagenicity]] or clastogenicity.
'''| [[Sotalol injection dosage and administration|Dosage and Administration]]'''
* No significant reduction in fertility occurred in rats at oral doses of 1000 mg/kg/ day (approximately 100 times the MRHD as mg/kg or 9 times the MRHD as mg/m2) prior to mating, except for a small reduction in the number of offspring per litter.
'''| [[Sotalol injection dosage forms and strengths|Dosage Forms and Strengths]]'''
|clinicalStudies======Prolongation of Time to Recurrence of Symptomatic Atrial Fibrillation/ Flutter=====
'''| [[Sotalol injection contraindications|Contraindications]]'''
'''| [[Sotalol injection warnings and precautions|Warnings and Precautions]]'''
'''| [[Sotalol injection adverse reactions|Adverse Reactions]]'''
'''| [[Sotalol injection drug interactions|Drug Interactions]]'''
'''| [[Sotalol injection use in specific populations|Use in Specific Populations]]'''
'''| [[Sotalol injection overdosage|Overdosage]]'''
'''| [[Sotalol injection description|Description]]'''
'''| [[Sotalol injection clinical pharmacology|Clinical Pharmacology]]'''
'''| [[Sotalol injection nonclinical toxicology|Nonclinical Toxicology]]'''
'''| [[Sotalol injection clinical studies|Clinical Studies]]'''
'''| [[Sotalol injection how supplied storage and handling|How Supplied/Storage and Handling]]'''
'''| [[Sotalol injection patient counseling information|Patient Counseling Information]]'''
'''| [[Sotalol injection labels and packages|Labels and Packages]]'''


{|
* Sotalol hydrochloride (AF) has been studied in patients with symptomatic [[AFIB]]/[[AFL]] in two principal studies, one in patients with primarily paroxysmal [[AFIB]]/[[AFL]], the other in patients with primarily chronic [[AFIB]].
| [[File:Sotabb2.png|thumb|800px]]
|}


==Pharmacology==
* In one study, a U.S. multicenter, randomized, placebo-controlled, double-blind, dose-response trial of patients with symptomatic primarily paroxysmal [[AFIB]]/[[AFL]], three fixed dose levels of sotalol hydrochloride (AF) (80 mg, 120 mg and 160 mg) twice daily and placebo were compared in 253 patients. In patients with reduced [[creatinine clearance]] (40-60 mL/min) the same doses were given once daily. Patients were not randomized for the following reasons: QT >450 msec; [[creatinine clearance]] <40 mL/min; intolerance to [[beta-blockers]]; [[bradycardia]]-[[tachycardia]] syndrome in the absence of an implanted pacemaker; [[AFIB]]/[[AFL]] was asymptomatic or was associated with [[syncope]], embolic [[CVA]] or [[TIA]]; acute [[myocardial infarction]] within the previous 2 months; [[congestive heart failure]]; [[bronchial asthma]] or other contraindications to [[beta-blocker]] therapy; receiving potassium losing [[diuretics]] without potassium replacement or without concurrent use of [[ACE-inhibitors]]; uncorrected [[hypokalemia]] (serum potassium <3.5 meq/L) or [[hypomagnesemia]] (serum magnesium <1.5 meq/L); received chronic oral [[amiodarone]] therapy for >1 month within previous 12 weeks; congenital or acquired [[long QT syndromes]]; history of [[Torsade de Pointes]] with other [[antiarrhythmic agents]] which increase the duration of ventricular repolarization; sinus rate <50 bpm during waking hours; unstable angina pectoris; receiving treatment with other drugs that prolong the QT interval; and AFIB/AFL associated with the [[Wolff-Parkinson-White syndrome]] (WPW). If the [[QT interval]] increased to ≥520 msec (or JT ≥430 msec if QRS >100 msec) the drug was discontinued. The patient population in this trial was 64% male, and the mean age was 62 years. No structural heart disease was present in 43% of the patients. Doses were administered once daily in 20% of the patients because of reduced [[creatinine clearance]].


It falls into the class III [[antiarrhythmic agents]] because it inhibits the inward [[potassium]] [[ion channel]]s in the heart. It is also a [[beta blocker]] because of its primary action on the &beta;-[[adrenergic receptor]]s in the heart.
* Sotalol hydrochloride (AF) was shown to prolong the time to the first symptomatic, [[ECG]] documented recurrence of [[AFIB]]/[[AFL]], as well as to reduce the risk of such recurrence at both 6 and 12 months. The 120 mg dose was more effective than 80 mg, but 160 mg did not appear to have an added benefit. Note that these doses were given twice or once daily, depending on renal function. The results are shown in the figure and tables below.


By blocking the [[potassium channel]]s, sotalol prolongs [[repolarization]], therefore lengthening the [[QT interval]] and decreasing [[automaticity]].
[[File:SotalolFigure1.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
[[File:SotalolTable1.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
Please note that columns do not add up to 100% due to discontinuations (D/C) for "other" reasons.
[[File:SotalolTable2.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}


It also slows [[AV node|atrioventricular (AV) nodal]] conduction (beta-blocking effect).
Discontinuation because of adverse events was dose related.


Sotalol is a [[racemic]] mix of D and L [[enantiomers]]. The ''L''-isomer is a [[beta blocker]].
* In a second multicenter, randomized, placebo-controlled, double-blind study of 6 months duration in 232 patients with chronic [[AFIB]], sotalol hydrochloride (AF) was titrated over a dose range from 80 mg/day to 320 mg/day. The patient population of this trial was 70% male with a mean age of 65 years. [[Structural heart disease]] was present in 49% of the patients. All patients had chronic [[AFIB]] for >2 weeks but <1 year at entry with a mean duration of 4.1 months. Patients were excluded if they had significant electrolyte imbalance, QTc >460 msec, QRS >140 msec, any degree of [[AV block]] or functioning pacemaker, uncompensated [[cardiac failure]], [[asthma]], significant [[renal disease]] (estimated creatinine clearance <50 mL/min), heart rate <50 bpm, [[myocardial infarction]] or open heart surgery in past 2 months, [[unstable angina]], [[infective endocarditis]], active [[pericarditis]] or [[myocarditis]], ≥ 3 DC cardioversions in the past, medications that prolonged [[QT interval]], and previous [[amiodarone]] treatment. After successful [[cardioversion]] patients were randomized to receive placebo (n=114) or sotalol hydrochloride (AF) (n=118), at a starting dose of 80 mg twice daily. If the initial dose was not tolerated it was decreased to 80 mg once daily, but if it was tolerated it was increased to 160 mg twice daily. During the maintenance period 67% of treated patients received a dose of 160 mg twice daily, and the remainder received doses of 80 mg once daily (17%) and 80 mg twice daily (16%).


Sotalol is not selected for its beta-blocking ability, but rather for its Class III (potassium blocking) properties.
* The figure and Tables below show the results of the trial. There was a longer time to ECG-documented recurrence of [[AFIB]] and a reduced risk of recurrence at 6 months compared to placebo.


==Indications==
[[File:SotalolFigure2.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
[[File:SotalolTable3.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}
[[File:SotalolTable4.png|800px|thumbnail|left|This image is provided by the National Library of Medicine.]]
{{clr}}


Sotalol is used to treat [[ventricular tachycardia]]s as well as [[atrial fibrillation]]. Betapace AF is specifically labeled for [[atrial fibrillation]].
=====Safety in Patients with Structural Heart Disease=====


Some evidence suggests that sotalol should be avoided in the setting of decreased [[ejection fraction]] due to [[myocardial infarction|heart attack]].
* In a multicenter double-blind randomized study reported by D. Julian et al, the effect of sotalol 320 mg once daily was compared with that of placebo in 1456 patients (randomized 3:2, sotalol to placebo) surviving an acute [[myocardial infarction]] ([[MI]]). Treatment was started 5 to 14 days after infarction. Patients were followed for 12 months. The mortality rate was 7.3% in the sotalol group and 8.9% in the placebo group, not a statistically significant difference. Although the results do not show evidence of a benefit of sotalol in this population, they do not show an added risk in post [[MI]] patients receiving sotalol.
|howSupplied======Sotalol Tablets=====
* Betapace (sotalol hydrochloride); capsule-shaped light-blue scored tablets imprinted with the strength and “Betapace”, are available as follows:
:* 80 mg strength, bottle of 100 (NDC 50419-105-10)
:* 120 mg strength, bottle of 100 (NDC 50419-109-10)
:* 160 mg strength, bottle of 100 (NDC 50419-106-10)


==References==
=====Sotalol Vial=====
* Intravenous sotalol is supplied in 10 mL vials, each containing 150 mg sotalol hydrochloride (15 mg/mL).
* Each vial is individually packed in a carton (NDC 67457-176-10).
|storage======Sotalol Tablets=====
* Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F).


{{Reflist|2}}
=====Sotalol Vial=====
* Store at 25°C (77°F) with excursions permitted to 15°-30° C (59°-86°F).
* Protect from freezing and light
|fdaPatientInfo=* Prior to initiation of sotalol (AF) therapy, the patient should be advised to read the patient package insert and reread it each time therapy is renewed. The patient should be fully instructed on the need for compliance with the recommended dosing of sotalol (AF), the potential interactions with drugs that prolong the [[QT interval]] and other antiarrhythmics, and the need for periodic monitoring of QT and renal function to minimize the risk of serious abnormal rhythms.


==See Also==
'''''Medications and Supplements'''''<br>
* Assessment of patients' medication history should include all over-counter, prescription and herbal/natural preparations with emphasis on preparations that may affect the pharmacodynamics of sotalol (AF) such as other cardiac [[antiarrhythmic drugs]], some [[phenothiazines]], [[bepridil]], [[tricyclic antidepressants]] and oral [[macrolides]]. Patients should be instructed to notify their health care providers of any change in over-the-counter, prescription or supplement use. If a patient is hospitalized or is prescribed a new medication for any condition, the patient must inform the health care provider of ongoing sotalol (AF) therapy. Patients should also check with their health care provider and/or pharmacist prior to taking a new over-the-counter medicine.


*[[Antiarrhythmic agents]]
'''''Electrolyte Imbalance'''''<br>
*[[Beta blocker]]
* If patients experience symptoms that may be associated with [[electrolyte disturbances]], such as excessive or prolonged [[diarrhea]], [[sweating]], or [[vomiting]], or loss of appetite or thirst, these conditions should be immediately reported to their health care provider.


{{beta blockers}}
'''''Dosing Schedule'''''<br>
* Patients should be instructed NOT to double the next dose if a dose is missed. The next dose should be taken at the usual time.
|alcohol=Alcohol-Sotalol interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.
|brandNames=* Betapace
* Betapace AF
* Sorine
|lookAlike=* Sotalol - Sudafed
|nlmPatientInfo=(Link to patient information page)
|drugShortage=Drug Shortage
}}
{{LabelImage
|fileName=BetapacePackage1.png
}}
{{LabelImage
|fileName=BetapacePackage2.png
}}
{{LabelImage
|fileName=BetapacePackage3.png
}}
{{LabelImage
|fileName=SotalolIVPackage.png
}}


[[Category:Antiarrhythmic agents]]
[[Category:Antiarrhythmic agents]]
[[Category:Sulfonamides]]
[[Category:Cardiovascular Drugs]]
[[Category:Drug]]
[[Category:Beta blockers]]
[[Category:Beta blockers]]
[[Category:Cardiovascular Drugs]]
[[Category:Drugs]]

Latest revision as of 17:10, 20 August 2015

{{DrugProjectFormSinglePage |authorTag=Alonso Alvarado, M.D. [1], Sheng Shi, M.D. [2], Rabin Bista, M.B.B.S. [3] |genericName=Sotalol |aOrAn=a |drugClass=Template:Beta-adrenergic blocker, Template:Antiarrhythmic |indicationType=treatment |indication=ventricular arrhythmias, symptomatic atrial fibtillation, symptomatic atriall flutter |hasBlackBoxWarning=Yes |adverseReactions=bradyarrhythmia, chest pain, lightheadedness, palpitations, rash, nausea, dizziness, headache, dyspnea, fatigue |blackBoxWarningTitle=WARNING |blackBoxWarningBody=INDUCED ARRHYTHMIA: To minimize the risk of induced arrhythmia, patients initiated or re-initiated on sotalol hydrochloride tablets (AF) should be placed for a minimum of three days (on their maintenance dose) in a facility that can provide cardiac resuscitation, continuous electrocardiographic monitoring and calculations of creatinine clearance. For detailed instructions regarding dose selection and special cautions for people with renal impairment. Sotalol is also indicated for the treatment of documented life-threatening ventricular arrhythmias and is marketed under the brand name Betapace (sotalol hydrochloride). Sotalol hydrochloride tablets, however, must not be substituted for Betapace AF (sotalol hydrochloride tablets, USP (AF)) because of significant differences in labeling (i.e. patient package insert, dosing administration and safety information). |fdaLIADAdult====Oral Tharapy===

  • Therapy with sotalol hydrochloride tablets (AF) must be initiated (and, if necessary, titrated) in a setting that provides continuous electrocardiographic (ECG) monitoring and in the presence of personnel trained in the management of serious ventricular arrhythmias. Patients should continue to be monitored in this way for a minimum of 3 days on the maintenance dose. In addition, patients should not be discharged within 12 hours of electrical or pharmacological conversion to normal sinus rhythm.
  • The QT interval is used to determine patient eligibility for sotalol hydrochloride tablets (AF) treatment and for monitoring safety during treatment. The baseline QT interval must be ≤450 msec in order for a patient to be started on sotalol hydrochloride tablets (AF) therapy. During initiation and titration, the QT interval should be monitored 2 to 4 hours after each dose. If the QT interval prolongs to 500 msec or greater, the dose must be reduced or the drug discontinued.
  • The dose of sotalol hydrochloride tablets, USP (AF) must be individualized according to calculated creatinine clearance. In patients with a creatinine clearance >60 mL/min sotalol hydrochloride tablets (AF) are administered twice daily (BID) while in those with a creatinine clearance between 40 and 60 mL/min, the dose is administered once daily (QD) or half the dose is administered twice daily (BID). In patients with a creatinine clearance less than 40 mL/min sotalol hydrochloride tablets (AF) are contraindicated. The recommended initial dose of sotalol hydrochloride tablets (AF) is 80 mg and is initiated as shown in the dosing algorithm described below. The 80 mg dose can be titrated upward to 100 mg or 120 mg during initial hospitalization or after discharge on 80 mg in the event of recurrence, by rehospitalization and repeating the same steps used during the initiation of therapy.
  • Patients with atrial fibrillation should be anticoagulated according to usual medical practice. Hypokalemia should be corrected before initiation of sotalol hydrochloride tablets (AF) therapy.
  • Patients to be discharged on sotalol hydrochloride tablets (AF) therapy from an in-patient setting should have an adequate supply of sotalol hydrochloride tablets (AF), to allow uninterrupted therapy until the patient can fill a sotalol hydrochloride tablets (AF) prescription.
Initiation of Sotalol Hydrochloride Tablets, USP (AF) Therapy
  • Step 1. Electrocardiographic assessment: Prior to administration of the first dose, the QT interval must be determined using an average of 5 beats. If the baseline QT is greater than 450 msec (JT ≥330 msec if QRS over 100 msec), sotalol hydrochloride tablets (AF) are contraindicated.
  • Step 2. Calculation of creatinine clearance: Prior to the administration of the first dose, the patient's creatinine clearance should be calculated using the following formula:
This image is provided by the National Library of Medicine.

When serum creatinine is given in μmol/L, divide the value by 88.4 (1 mg/dL = 88.4 mcmol/L).

  • Step 3. Starting Dose: The starting dose of sotalol hydrochloride tablets (AF) is 80 mg twice daily (BID) if the creatinine clearance is >60 mL/min, and 80 mg once daily (QD) if the creatinine clearance is 40 to 60 mL/min. If the creatinine clearance is <40 mL/min sotalol hydrochloride tablets (AF) are contraindicated.
  • Step 4. Administer the appropriate daily dose of sotalol hydrochloride tablets (AF) and begin continuous ECG monitoring with QT interval measurements 2 to 4 hours after each dose.
  • Step 5. In patients with a creatinine clearance >60 mL/min, if the 80 mg dose level is tolerated and the QT interval remains <500 msec after at least 3 days (after 5 or 6 doses if patient receiving QD dosing), the patient can be discharged. Alternatively, during hospitalization, the dose can be increased to 100 mg or 120 mg BID and the patient followed for 3 days on this dose (followed for 5 or 6 doses if patient receiving QD doses).

The steps described above are summarized in the following diagram:

  • Place Patient on Telemetry
  • Check Baseline QT
  • If QT >450 msec sotalol hydrochloride tablets (AF) are CONTRAINDICATED
  • If QT ≤450 msec, proceed
  • Calculate Creatine Clearance (Clcr)
  • If Clcr is <40 mL/min sotalol hydrochloride tablets (AF) are CONTRAINDICATED
  • If Clcr is 40-60 mL/min start sotalol hydrochloride tablets (AF) 80 mg QD
  • If Clcr is >60 mL/min start sotalol hydrochloride tablets (AF) 80 mg BID
  • Monitor QT 2 to 4 hours after each dose.
  • If QT ≥500 msec discontinue sotalol hydrochloride tablets (AF)
  • If QT <500 msec after 3 days (after 5th or 6th dose if patient receiving QD dosing) discharge patient on current treatment. Alternatively, during hospitalization, the dose can be increased to 120 mg BID and the patient followed for 3 days on this dose (followed for 5 or 6 doses if patient receiving QD doses).
Upward Titration of Dose
  • If the 80 mg dose level (given BID or QD depending upon the creatinine clearance) does not reduce the frequency of relapses of AFIB/AFL and is tolerated without excessive QT interval prolongation (i.e., ≥520 msec), the dose level may be increased to 120 mg (BID or QD depending upon the creatinine clearance). As proarrhythmic events can occur not only at initiation of therapy, but also with each upward dosage adjustment, Steps 2 through 5 used during initiation of sotalol hydrochloride tablet (AF) therapy should be followed when increasing the dose level. In the U.S. multicenter dose-response study, the 120 mg dose (BID or QD) was found to be the most effective in prolonging the time to ECG documented symptomatic recurrence of AFIB/AFL. If the 120 mg dose does not reduce the frequency of early relapse of AFIB/AFL and is tolerated without excessive QT interval prolongation (≥520 msec), an increase to 160 mg (BID or QD depending upon the creatinine clearance), can be considered. Steps 2 through 5 used during the initiation of therapy should be used again to introduce such an increase.
Maintenance of Sotalol Hydrochloride Tablets, USP (AF) Therapy
  • Renal function and QT should be re-evaluated regularly if medically warranted. If QT is 520 msec or greater (JT 430 msec or greater if QRS is > 100 msec), the dose of sotalol hydrochloride tablets (AF) therapy should be reduced and patients should be carefully monitored until QT returns to less than 520 msec. If the QT interval is ≥520 msec while on the lowest maintenance dose level (80 mg) the drug should be discontinued. If renal function deteriorates, reduce the daily dose in half by administering the drug once daily as described in Initiation of sotalol hydrochloride tablets (AF) Therapy, Step 3.
Special Considerations
  • The maximum recommended dose in patients with a calculated creatinine clearance greater than 60 mL/min is 160 mg BID, doses greater than 160 mg BID have been associated with an increased incidence of Torsade de Pointes and are not recommended.
  • A patient who misses a dose should NOT double the next dose. The next dose should be taken at the usual time.

IV Therapy

General Rules and Safety Measures of Intravenous Sotalol Therapy
  • For the safety of the patient, the safety measures required of oral sotalol administration must also be applied for intravenous route. To minimize the risk of induced arrhythmia, patients initiated or re-initiated on sotalol should be hospitalized for at least three days or until steady state drug levels are achieved, in a facility that can provide cardiac resuscitation and continuous electrocardiographic monitoring. Initiate intravenous sotalol therapy in the presence of personnel trained in the management of serious ventricular arrhythmias. Perform a baseline ECG to determine the QT interval and measure and normalize serum potassium and magnesium levels before initiating therapy with starting sotalol injection. Measure serum creatinine and calculate an estimated creatinine clearance in order to establish the appropriate dosing interval for sotalol.
  • If the baseline QT is greater than 450 ms (JT >330 ms if QRS over 100 ms), sotalol is not recommended.
  • The patient's creatinine clearance should be calculated using the one of several formulas. The Cockcroft-Gault formula to determine creatinine clearance is:
This image is provided by the National Library of Medicine.
  • When serum creatinine is given in µmol/L, divide the value by 88.4 (1 mg/dL = 88.4 µmol/L).
  • Start sotalol therapy only if the baseline QT interval is <450 ms. During initiation and titration, monitor the QT interval after the completion of each infusion If the QT interval prolongs to 500 ms or greater, reduce the dose, decrease the infusion rate, or discontinue the drug.
  • Administer sotalol twice daily in patients with a creatinine clearance >60 mL/min or once daily) in patients with a creatinine clearance between 40 and 60 mL/min. Sotalol is not recommended in patients with a creatinine clearance <40 mL/min. The recommended initial IV dose of sotalol is 75 mg (once or twice daily) and is initiated as shown in the dosing algorithm described below. The 75 mg dose can be titrated upward to 112.5 or 150 mg after at least 3 days.
Dose of Intravenous Sotalol
  • The bioavailability of oral sotalol is between 90% and 100%. The corresponding dose of intravenous sotalol is, therefore, slightly less than that of the oral dose. The effects of the initial intravenous dose must be monitored and the dose titrated either upward or downward, if needed, based on clinical effect, QT interval, or adverse reactions.
This image is provided by the National Library of Medicine.
Preparation of Sotalol Infusion
  • Intravenous sotalol must be diluted for infusion. Appropriate diluents are saline, 5% dextrose in water (D5W), or Ringer's lactate. Usually, prepare in a volume of 100-250 mL. Use a volumetric infusion pump to infuse intravenous sotalol at a constant rate. The following table compensates for dead space in the infusion set.
This image is provided by the National Library of Medicine.
Initiation of Intravenous Sotalol Therapy
  • The starting dose of intravenous sotalol is 75 mg infused over 5 hours once or twice daily based on the creatinine clearance. Monitor ECG for excessive increase in QTc.
Upward Titration of Dose
  • If the 75 mg dose of intravenous sotalol does not reduce the frequency of relapses of life threatening ventricular arrhythmias or symptomatic AFIB/AFL and is tolerated without excessive (i.e., to >500 ms) QTc prolongation, increase the dose to 112.5 mg infused over 5 hours, once or twice daily depending upon the creatinine clearance. Continue to monitor QTc during dose escalations.
Dose for Ventricular Arrhythmias
  • The recommended initial dose of intravenous sotalol is 75 mg infused over 5 hours, once or twice daily based on creatinine clearance. The dose may be increased in increments of 75 mg/day every 3 days. The usual therapeutic effect is observed with oral doses of 80 to 160 mg once or twice a day (corresponding to 75 to 150 mg intravenous sotalol). Oral doses as high as 240-320 mg once or twice a day (corresponding to 225 to 300 mg intravenous sotalol) have been utilized in patients with refractory life-threatening arrhythmias.
Dose for Symptomatic AFIB/AFL
  • In the U.S. multicenter dose-response study, 120 mg orally once or twice a day (corresponding to 112.5 mg intravenous sotalol) was found to be the most effective dose in prolonging the time to ECG-documented symptomatic recurrence of AFIB/AFL. If that dose level, at steady state, does not reduce the frequency of early relapse of arrhythmia and is tolerated without excessive QTc prolongation (>520 ms), increase the dose to 160 mg orally once or twice a day (corresponding to 150 mg intravenous sotalol).

|offLabelAdultGuideSupport=There is limited information regarding Off-Label Guideline-Supported Use of Sotalol in adult patients. |offLabelAdultNoGuideSupport======Angina Pectoris=====

  • Dosing Information
  • 120 to 480 mg PO q24h.[1]
  • 20 mg IV as single dose.[2]
Hypertension
  • Dosing Information
  • 80 to 320 mg PO q24h.[3]

|fdaLIADPed====Oral Therapy===

  • As in adults the following precautionary measures should be considered when initiating sotalol treatment in children: initiation of treatment in the hospital after appropriate clinical assessment; individualized regimen as appropriate; gradual increase of doses if required; careful assessment of therapeutic response and tolerability; and frequent monitoring of the QTc interval and heart rate.
For children aged about 2 years and greater
  • For children aged about 2 years and greater, with normal renal function, doses normalized for body surface area are appropriate for both initial and incremental dosing. Since the Class III potency in children is not very different from that in adults, reaching plasma concentrations that occur within the adult dose range is an appropriate guide. From pediatric pharmacokinetic data the following is recommended.
  • For initiation of treatment, 30 mg/m2 three times a day (90 mg/m2 total daily dose) is approximately equivalent to the initial 160 mg total daily dose for adults. Subsequent titration to a maximum of 60 mg/m2 (approximately equivalent to the 360 mg total daily dose for adults) can then occur. Titration should be guided by clinical response, heart rate and QTc, with increased dosing being preferably carried out in-hospital. At least 36 hours should be allowed between dose increments to attain steady-state plasma concentrations of sotalol in patients with age-adjusted normal renal function.
For children aged about 2 years or younger
  • For children aged about 2 years or younger the above pediatric dosage should be reduced by a factor that depends heavily upon age, as shown in the following graph, age plotted on a logarithmic scale in months.
This image is provided by the National Library of Medicine.
  • For a child aged 20 months, the dosing suggested for children with normal renal function aged 2 years or greater should be multiplied by about 0.97; the initial starting dose would be (30 X 0.97)=29.1 mg/m2, administered three times daily. For a child aged 1 month, the starting dose should be multiplied by 0.68; the initial starting dose would be (30 X 0.68)=20 mg/m2, administered three times daily. For a child aged about 1 week, the initial starting dose should be multiplied by 0.3; the starting dose would be (30 X 0.3)=9 mg/m2. Similar calculations should be made for increased doses as titration proceeds. Since the half-life of sotalol decreases with decreasing age (below about 2 years), time to steady-state will also increase. Thus, in neonates the time to steady-state may be as long as a week or longer.
  • In all children, individualization of dosage is required. As in adults sotalol hydrochloride tablets (AF) should be used with particular caution in children if the QTc is greater than 500 msec on therapy and serious consideration should be given to reducing the dose or discontinuing therapy when QTc exceeds 550 msec.

The use of sotalol hydrochloride tablets (AF) in children with renal impairment has not been investigated. Sotalol elimination is predominantly via the kidney in the unchanged form. Use of sotalol in any age group with decreased renal function should be at lower doses or at increased intervals between doses. Monitoring of heart rate and QTc is more important and it will take much longer to reach steady-state with any dose and/or frequency of administration.

Transfer to Sotalol Hydrochloride Tablets (AF) from Sotalol Hydrochloride Tablets
  • Patients with a history of symptomatic AFIB/AFL who are currently receiving sotalol hydrochloride for the maintenance of normal sinus should be transferred to sotalol hydrochloride tablets (AF) because of the significant differences in labeling (i.e., patient package insert, dosing administration, and safety information).
Transfer to Sotalol Hydrochloride Tablets (AF) from Other Antiarrhythmic Agents
  • Before starting sotalol hydrochloride tablets (AF), previous antiarrhythmic therapy should generally be withdrawn under careful monitoring for a minimum of 2 to 3 plasma half-lives if the patient's clinical condition permits. Treatment has been initiated in some patients receiving I.V. lidocaine without ill effect. After discontinuation of amiodarone, sotalol hydrochloride tablets (AF) should not be initiated until the QT interval is normalized.

Preparation of Extemporaneous Oral Solution

  • Sotalol hydrochloride (AF) Syrup 5 mg/mL can be compounded using Simple Syrup containing 0.1% sodium benzoate (Syrup, NF) available from Humco Laboratories as follows:
  1. Measure 120 mL of Simple Syrup
  2. Transfer the syrup to a 6-ounce amber plastic (polyethylene terephthalate [PET]) prescription bottle. NOTE: An oversized bottle is used to allow for a headspace, so that there will be more effective mixing during shaking of the bottle.
  3. Add five (5) sotalol hydrochloride (AF) 120 mg tablets to the bottle. These tablets are added intact; it is not necessary to crush the tablets. NOTE: The addition of the tablets can also be done first. The tablets can also be crushed if preferred. If the tablets are crushed, care should be taken to transfer the entire quantity of tablet powder into the bottle containing the syrup.
  4. Shake the bottle to wet the entire surface of the tablets. If the tablets have been crushed, shake the bottle until the endpoint is achieved.
  5. Allow the tablets to hydrate for approximately two hours.
  6. After at least two hours have elapsed, shake the bottle intermittently over the course of at least another two hours until the tablets are completely disintegrated. NOTE: The tablets can be allowed to hydrate overnight to simplify the disintegration process.
  • The endpoint is achieved when a dispersion of fine particles in the syrup is obtained.
  • This compounding procedure results in a solution containing 5 mg/mL of sotalol HCl. The fine solid particles are the water-insoluble inactive ingredients of the tablets.
  • This extemporaneously prepared oral solution of sotalol HCl (with suspended inactive particles) must be shaken well prior to administration. This is to ensure that the amount of inactive solid particles per dose remains constant throughout the duration of use.
  • Stability studies indicate that the suspension is stable when stored at controlled room temperature (15° to 30°C/59° to 86°F) and ambient humidity for three (3) months.

IV Therapy

  • Intravenous sotalol has not been studied in children. As in adults the following precautionary measures should be considered when initiating sotalol treatment in children: initiation of treatment in the hospital after appropriate clinical assessment; individualized regimen as appropriate; gradual increase of doses if required; careful assessment of therapeutic response and tolerability; and frequent monitoring of the QTc interval and heart rate.
For children aged about 2 years and greater
  • For children aged about 2 years and greater, with normal renal function, doses normalized for body surface area are appropriate for both initial and incremental dosing. Since the Class III potency in children is not very different from that in adults, reaching plasma concentrations that occur within the adult dose range is an appropriate guide. From pediatric pharmacokinetic data the following is recommended. For initiation of treatment, 30 mg/m2 three times a day (90 mg/m2 total daily dose) is approximately equivalent to the initial 160 mg total oral daily dose for adults. Subsequent titration to a maximum of 60 mg/m2 (approximately equivalent to the 360 mg total daily dose for adults) can then occur. Titration should be guided by clinical response, heart rate and QTc, with increased dosing being carried out in-hospital. At least 36 hours should be allowed between dose increments to attain steady-state plasma concentrations of sotalol in patients with age-adjusted normal renal function.
For children aged about 2 years or younger
  • For children about 2 years or younger the above pediatric dosage should be reduced by a factor that depends heavily upon age, as shown in the following graph which shows age plotted on a logarithmic scale in months.
This image is provided by the National Library of Medicine.
  • For a child aged 20 months, the dosing suggested for children with normal renal function aged 2 years or greater should be multiplied by about 0.97; the initial starting dose would be (30 × 0.97) = 29.1 mg/m2, administered orally three times daily. For a child aged 1 month, the starting dose should be multiplied by 0.68; the initial starting dose would be (30 × 0.68) = 20 mg/m2, administered orally three times daily. For a child aged 1 week, the initial starting oral dose should be multiplied by 0.3; the starting dose would be (30 × 0.3) = 9 mg/m2. Similar calculations should be made for increased doses as titration proceeds. Since the half-life of sotalol decreases with decreasing age (below about 2 years), time to steady-state will also increase. Thus, in neonates the time to steady-state may be as long as a week or longer.
  • In all children, individualization of dosage is required. As in adults sotalol should be used with particular caution in children if the QTc is greater than 500 ms on therapy and serious consideration should be given to reducing the dose or discontinuing therapy when QTc exceeds 550 ms.
  • The use of oral sotalol in children with renal impairment has not been investigated. Sotalol elimination is predominantly via the kidney in the unchanged form. Use of sotalol in any age group with decreased renal function should be at lower doses or at increased intervals between doses. Monitoring of heart rate and QTc is most important. It will take much longer to reach steady-state with any dose and/or frequency of administration in these children.

|offLabelPedGuideSupport=There is limited information regarding Off-Label Guideline-Supported Use of Sotalol in pediatric patients. |offLabelPedNoGuideSupport=There is limited information regarding Off-Label Non–Guideline-Supported Use of Sotalol in pediatric patients. |contraindications=* Bronchial asthma.

|warnings======Ventricular Arrhythmia=====

  • Treatment with sotalol (AF) must therefore be started only in patients observed for a minimum of three days on their maintenance dose in a facility that can provide electrocardiographic monitoring and in the presence of personnel trained in the management of serious ventricular arrhythmias. Calculation of the creatinine clearance must precede administration of the first dose of sotalol (AF). For detailed instructions regarding dose selection.
Proarrhythmia in Atrial Fibrillation/Atrial Flutter Patients
  • In eight controlled trials of patients with AFIB/AFL and other supraventricular arrhythmias (N=659) there were four cases of Torsade de Pointes reported (0.6%) during the controlled phase of treatment with sotalol (AF). The incidence of Torsade de Pointes was significantly lower in those patients receiving total daily doses of 320 mg or less (0.3%), as summarized in Table 5 below. Both patients who had Torsade de Pointes in the group receiving >320 mg/day were receiving 640 mg/day. In the group receiving ≤320 mg daily, one case of TdP occurred at a daily dose of 320 mg on day 4 of treatment and one case occurred on a daily dose of 160 mg on day 1 of treatment.
This image is provided by the National Library of Medicine.
  • The table below relates the incidence of Torsade de Pointes to on-therapy QTc and change in QTc from baseline. It should be noted, however, that the highest on therapy QTc was in many cases the one obtained at the time of the Torsade de Pointes event, so that the table overstates the predictive value of a high QTc.
This image is provided by the National Library of Medicine.
Use with Drugs that Prolong QT Interval and Antiarrhythmic Agents
  • The use of sotalo (AF) in conjunction with other drugs that prolong the QT interval has not been studied and is not recommended. Such drugs include many antiarrhythmics, some phenothiazines, bepridil, tricyclic antidepressants, and certain oral macrolides. Class I or Class III antiarrhythmic agents should be withheld for at least three half-lives prior to dosing with sotalol (AF). In clinical trials, sotalots (AF) was not administered to patients previously treated with oral amiodarone for >1 month in the previous three months. Class Ia antiarrhythmic drugs, such as disopyramide, quinidine and procainamide and other Class III drugs (e.g., amiodarone) are not recommended as concomitant therapy with sotalots (AF), because of their potential to prolong refractoriness. There is only limited experience with the concomitant use of Class Ib or Ic antiarrhythmics.
Congestive Heart Failure
  • Sympathetic stimulation is necessary in supporting circulatory function in congestive heart failure, and beta-blockade carries the potential hazard of further depressing myocardial contractility and precipitating more severe failure. In patients who have heart failure controlled by digitalis and/or diuretics, sotalol (AF) should be administered cautiously. Both digitalis and sotalol slow AV conduction. As with all beta-blockers, caution is advised when initiating therapy in patients with any evidence of left ventricular dysfunction. In a pooled data base of four placebo-controlled AFIB/AFL and PSVT studies, new or worsening CHF occurred during therapy with sotalol (AF) in 5 (1.2%) of 415 patients. In these studies patients with uncontrolled heart failure were excluded (i.e., NYHA Functional Classes III or IV). In other premarketing sotalol studies, new or worsened congestive heart failure (CHF) occurred in 3.3% (n=3257) of patients and led to discontinuation in approximately 1% of patients receiving sotalol. The incidence was higher in patients presenting with sustained ventricular tachycardia/ventricular fibrillation (4.6%, n=1363), or a prior history of heart failure (7.3%, n=696). Based on a life-table analysis, the one-year incidence of new or worsened CHF was 3% in patients without a prior history and 10% in patients with a prior history of CHF. NYHA Classification was also closely associated to the incidence of new or worsened heart failure while receiving sotalol (1.8% in 1395 Class I patients, 4.9% in 1254 Class II patients and 6.1% in 278 Class III or IV patients).
Electrolyte Disturbances
  • Sotalol (AF) should not be used in patients with hypokalemia or hypomagnesemia prior to correction of imbalance, as these conditions can exaggerate the degree of QT prolongation, and increase the potential for Torsade de Pointes. Special attention should be given to electrolyte and acid-base balance in patients experiencing severe or prolonged diarrhea or patients receiving concomitant diuretic drugs.
Bradycardia/Heart Block
  • The incidence of bradycardia (as determined by the investigators) in the supraventricular arrhythmia population treated with sotalol (AF) (N = 415) was 13%, and led to discontinuation in 2.4% of patients. Bradycardia itself increases the risk of Torsade de Pointes.
Recent Acute MI
  • Sotalol has been used in a controlled trial following an acute myocardial infarction without evidence of increased mortality (see Safety in Patients with Structural Heart Disease). Although specific studies of its use in treating atrial arrhythmias after infarction have not been conducted, the usual precautions regarding heart failure, avoidance of hypokalemia, bradycardia or prolonged QT interval apply.
Warnings related to the beta-blocking activity of sotalol AF
Abrupt Withdrawal
  • Hypersensitivity to catecholamines has been observed in patients withdrawn from beta-blocker therapy. Occasional cases of exacerbation of angina pectoris, arrhythmias and, in some cases, myocardial infarction have been reported after abrupt discontinuation of beta-blocker therapy. Therefore, it is prudent when discontinuing chronically administered sotalol (AF), particularly in patients with ischemic heart disease, to carefully monitor the patient and consider the temporary use of an alternate beta-blocker if appropriate. If possible, the dosage of sotalol (AF) should be gradually reduced over a period of one to two weeks. If angina or acute coronary insufficiency develops, appropriate therapy should be instituted promptly. Patients should be warned against interruption or discontinuation of therapy without the physician's advice. Because coronary artery disease is common and may be unrecognized in patients receiving sotalols (AF), abrupt discontinuation in patients with arrhythmias may unmask latent coronary insufficiency.
Non-Allergic Bronchospasm (e.g., chronic bronchitis and emphysema)
  • PATIENTS WITH BRONCHOSPASTIC DISEASES SHOULD IN GENERAL NOT RECEIVE BETA-BLOCKERS. It is prudent, if sotalol hydrochloride (AF) is to be administered, to use the smallest effective dose, so that inhibition of bronchodilation produced by endogenous or exogenous catecholamine stimulation of beta2 receptors may be minimized.
Anaphylaxis
  • While taking beta-blockers, patients with a history of anaphylactic reaction to a variety of allergens may have a more severe reaction on repeated challenge, either accidental, diagnostic or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat the allergic reaction.
Major Surgery
  • Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures.
Diabetes
Sick Sinus Syndrome
  • Sotalol (AF) should be used only with extreme caution in patients with sick sinus syndrome associated with symptomatic arrhythmias, because it may cause sinus bradycardia, sinus pauses or sinus arrest. In patients with AFIB and sinus node dysfunction, the risk of Torsade de Pointes with sotalol (AF) therapy is increased, especially after cardioversion. Bradycardia following cardioversion in these patients is associated with QTc interval prolongation which is augmented due to the reverse use dependence of the Class III effects of sotalol (AF). Patients with AFIB/AFL associated with the sick sinus syndrome may be treated with sotalol (AF) if they have an implanted pacemaker for control of bradycardia symptoms.
Thyrotoxicosis

|clinicalTrials=* Adverse events that are clearly related to sotalol AF are those which are typical of its Class II (beta-blocking) and Class III (cardiac action potential duration prolongation) effects. The common documented beta-blocking adverse events (bradycardia, dyspnea, and fatigue) and Class III effects (QT interval prolongation) are dose related.

  • In a pooled clinical trial population consisting of four placebo-controlled studies with 275 patients with AFIB/AFL treated with 160 to 320 mg doses of sotalol hydrochloride (AF), the following adverse events were reported at a rate of 2% or more in the 160-240 mg treated patients and greater than the rate in placebo patients (See Table 8). The data are presented by incidence of events in the sotalol (AF) and placebo groups by body system and daily dose. No significant irreversible non-cardiac end-organ toxicity was observed.
This image is provided by the National Library of Medicine.
  • Overall, discontinuation because of unacceptable adverse events was necessary in 17% of the patients, and occurred in 10% of patients less than two weeks after starting treatment. The most common adverse events leading to discontinuation of sotalol hydrochloride (AF) were: fatigue 4.6%, bradycardia 2.4%, proarrhythmia 2.2%, dyspnea 2%, and QT interval prolongation 1.4%.
  • In clinical trials involving 1292 patients with sustained VT/VF, the common adverse events (occurring in ≥2% of patients) were similar to those described for the AFIB/AFL population.
  • Occasional reports of elevated serum liver enzymes have occurred with sotalol therapy but no cause and effect relationship has been established. One case of peripheral neuropathy which resolved on discontinuation of sotalol and recurred when the patient was rechallenged with the drug was reported in an early dose tolerance study. Elevated blood glucose levels and increased insulin requirements can occur in diabetic patients.
  • In an unblinded multicenter trial of 25 patients with SVT and/or VT receiving daily doses of 30, 90 and 210 mg/m2 with dosing every 8 hours for a total of 9 doses, no Torsades de Pointes or other serious new arrhythmias were observed. One (1) patient, receiving 30 mg/m2 daily, was discontinued because of increased frequency of sinus pauses/bradycardia. Additional cardiovascular AEs were seen at the 90 and 210 mg/m2 daily dose levels. They included QT prolongations (2 patients), sinus pauses/bradycardia (1 patient), increased severity of atrial flutter and reported chest pain (1 patient). Values for QTc ≥525 msec were seen in 2 patients at the 210 mg/m2 daily dose level. Serious adverse events including death, Torsades de Pointes, other proarrhythmias, high-degree AV blocks and bradycardia have been reported in infants and/or children.
Potential Adverse Effects
  • The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been associated with sotalol (AF) during investigational use and foreign marketing experience.

|drugInteractions=* Drugs undergoing CYP450 metabolism: Sotalol is primarily eliminated by renal excretion; therefore, drugs that are metabolized by CYP450 are not expected to alter the pharmacokinetics of sotalol.

  • Digoxin: Proarrhythmic events were more common in sotalol treated patients also receiving digoxin; it is not clear whether this represents an interaction or is related to the presence of CHF, a known risk factor for proarrhythmia, in the patients receiving digoxin. Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia.
  • Calcium blocking drugs: Sotalol (AF) should be administered with caution in conjunction with calcium blocking drugs because of possible additive effects on atrioventricular conduction or ventricular function. Additionally, concomitant use of these drugs may have additive effects on blood pressure, possibly leading to hypotension.
  • Catecholamine-depleting agents: Concomitant use of catecholamine-depleting drugs, such as reserpine and guanethidine, with a beta-blocker may produce an excessive reduction of resting sympathetic nervous tone. Patients treated with sotalol (AF) plus a catecholamine depletor should therefore be closely monitored for evidence of hypotension and/or marked bradycardia which may produce syncope.
  • Insulin and oral antidiabetics: Hyperglycemia may occur, and the dosage of insulin or antidiabetic drugs may require adjustment. Symptoms of hypoglycemia may be masked.
  • Beta-2-receptor stimulants: Beta-agonists such as salbutamol, terbutaline and isoprenaline may have to be administered in increased dosages when used concomitantly with sotalol (AF).
  • Clonidine: Beta-blocking drugs may potentiate the rebound hypertension sometimes observed after discontinuation of clonidine; therefore, caution is advised when discontinuing clonidine in patients receiving sotalol (AF).
  • Other: No pharmacokinetic interactions were observed with hydrochlorothiazide or warfarin.
  • Antacids: Administration of sotalol (AF) within 2 hours of antacids containing aluminum oxide and magnesium hydroxide should be avoided because it may result in a reduction in Cmax and AUC of 26% and 20%, respectively and consequently in a 25% reduction in the bradycardic effect at rest. Administration of the antacid two hours after sotalol (AF) has no effect on the pharmacokinetics or pharmacodynamics of sotalol.
  • Drug/Laboratory Test Interactions: The presence of sotalol in the urine may result in falsely elevated levels of urinary metanephrine when measured by fluorimetric or photometric methods. In screening patients suspected of having a pheochromocytoma and being treated with sotalol, a specific method, such as a high performance liquid chromatographic assay with solid phase extraction (e.g., J. Chromatogr. 385:241, 1987) should be employed in determining levels of catecholamines.

|FDAPregCat=B |useInPregnancyFDA=* Reproduction studies in rats and rabbits during organogenesis at 100 and 22 times the MRHD as mg/kg (9 and 7 times the MRHD as mg/m2), respectively, did not reveal any teratogenic potential associated with sotalol HCl. In rabbits, a high dose of sotalol HCl (160 mg/kg/day) at 16 times the MRHD as mg/kg (6 times the MRHD as mg/m2) produced a slight increase in fetal death likely due to maternal toxicity. Eight times the maximum dose (80 mg/kg/day or 3 times the MRHD as mg/m2) did not result in an increased incidence of fetal deaths. In rats, 1000 mg/kg/day sotalol HCl, 100 times the MRHD (18 times the MRHD as mg/m2), increased the number of early resorptions, while at 14 times the maximum dose (2.5 times the MRHD as mg/m2), no increase in early resorptions was noted. However, animal reproduction studies are not always predictive of human response.

  • Although there are no adequate and well-controlled studies in pregnant women, sotalol HCl has been shown to cross the placenta, and is found in amniotic fluid. There has been a report of subnormal birth weight with sotalol. Therefore, sotalol (AF) should be used during pregnancy only if the potential benefit outweighs the potential risk.

|useInNursing=* Sotalol is excreted in the milk of laboratory animals and has been reported to be present in human milk. Because of the potential for adverse reactions in nursing infants from sotalol (AF), a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. |useInPed=* The safety and effectiveness of sotalol (AF) in children have not been established. However, the Class III electrophysiologic and beta-blocking effects, the pharmacokinetics, and the relationship between the effects (QTc interval and resting heart rate) and drug concentrations have been evaluated in children aged between 3 days and 12 years old. |useInRenalImpair=* Sotalol hydrochloride (AF) is eliminated principally via the kidneys through glomerular filtration and to a small degree by tubular secretion. There is a direct relationship between renal function, as measured by serum creatinine or creatinine clearance, and the elimination rate of sotalol hydrochloride (AF). |administration=Oral/Intravenous |monitoring======Ventricular Arrhythmias=====

  • Administer the appropriate daily dose of sotalol hydrochloride tablets (AF) and begin continuous ECG monitoring with QT interval measurements 2 to 4 hours after each dose.

|overdose=Intentional or accidental overdosage with sotalol has rarely resulted in death.

Symptoms and Treatment of Overdosage

|drugBox={{Drugbox2 | verifiedrevid = 420038718 | IUPAC_name = (RS)-N-{4-[1-hydroxy-2-(propan-2-ylamino)ethyl]phenyl}methanesulfonamide | image = SotalolStructure.png | imagename = 1 : 1 mixture (racemate) | drug_name = Sotalol

| tradename = Betapace | Drugs.com = Monograph | MedlinePlus = a693010 | pregnancy_AU = | pregnancy_US = B | pregnancy_category = | legal_status = Rx-only | routes_of_administration = oral

| bioavailability = >95% | metabolism = Not metabolized[citation needed] | elimination_half-life = 12 hours | excretion = Renal
Lactic (In lactating females)

| CASNo_Ref =  ☑Y | CAS_number_Ref =  ☑Y | CAS_number = 3930-20-9 | ATC_prefix = C07 | ATC_suffix = AA07 | PubChem = 5253 | DrugBank_Ref =  ☑Y | DrugBank = DB00489 | ChemSpiderID_Ref =  ☑Y | ChemSpiderID = 5063 | UNII_Ref =  ☑Y | UNII = A6D97U294I | KEGG_Ref =  ☑Y | KEGG = D08525 | ChEMBL_Ref =  ☑Y | ChEMBL = 471

| C=12 | H=20 | N=2 | O=3 | S=1 | molecular_weight = 272.3624 g/mol | smiles = O=S(=O)(Nc1ccc(cc1)C(O)CNC(C)C)C | InChI = 1/C12H20N2O3S/c1-9(2)13-8-12(15)10-4-6-11(7-5-10)14-18(3,16)17/h4-7,9,12-15H,8H2,1-3H3 | InChIKey = ZBMZVLHSJCTVON-UHFFFAOYAR | StdInChI_Ref =  ☑Y | StdInChI = 1S/C12H20N2O3S/c1-9(2)13-8-12(15)10-4-6-11(7-5-10)14-18(3,16)17/h4-7,9,12-15H,8H2,1-3H3 | StdInChIKey_Ref =  ☑Y | StdInChIKey = ZBMZVLHSJCTVON-UHFFFAOYSA-N }} |mechAction=* Sotalol hydrochloride has both beta-blocker (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) antiarrhythmic properties. Sotalol hydrochloride is a racemic mixture of d- and l-sotalol. Both isomers have similar Class III antiarrhythmic effects, while the l-isomer is responsible for virtually all of the beta-blocking activity. The beta-blocking effect of sotalol is non-cardioselective, half maximal at about 80 mg/day and maximal at doses between 320 and 640 mg/day. Sotalol does not have partial agonist or membrane stabilizing activity. Although significant beta-blockade occurs at oral doses as low as 25 mg, significant Class III effects are seen only at daily doses of 160 mg and above.

  • In children, a Class III electrophysiologic effect can be seen at daily doses of 210 mg/m2 body surface area (BSA). A reduction of the resting heart rate due to the beta-blocking effect of sotalol is observed at daily doses ≥ 90 mg/m2 in children.

|structure=* Sotalol hydrochloride is an antiarrhythmic drug with Class II (beta-blocker) and Class III (cardiac action potential duration prolongation) properties. It is supplied as a light-blue, capsule-shaped tablet for oral administration. Sotalol hydrochloride is a white, crystalline solid with a molecular weight of 308.8. It is hydrophilic, soluble in water, propylene glycol and ethanol, but is only slightly soluble in chloroform. Chemically, sotalol hydrochloride is d,l-N -[4-[1-hydroxy-2-[(1-methylethyl) amino]ethyl]phenyl]methane-sulfonamide monohydrochloride. The molecular formula is C12H20N2O3 S·HCl and is represented by the following structural formula:

This image is provided by the National Library of Medicine.
  • Satolol tablets contain the following inactive ingredients: microcrystalline cellulose, lactose, starch, stearic acid, magnesium stearate, colloidal silicon dioxide, and FD&C blue color #2 (aluminum lake, conc.).

|PD=* Sotalol hydrochloride prolongs the plateau phase of the cardiac action potential in the isolated myocyte, as well as in isolated tissue preparations of ventricular or atrial muscle (Class III activity). In intact animals it slows heart rate, decreases AV nodal conduction and increases the refractory periods of atrial and ventricular muscle and conduction tissue.

  • In man, the Class II (beta-blockade) electrophysiological effects of sotalol are manifested by increased sinus cycle length (slowed heart rate]), decreased AV nodal conduction and increased AV nodal refractoriness. The Class III electrophysiological effects in man include prolongation of the atrial and ventricular monophasic action potentials, and effective refractory period prolongation of atrial muscle, ventricular muscle, and atrio-ventricular accessory pathways (where present) in both the anterograde and retrograde directions. With oral doses of 160 to 640 mg/day, the surface ECG shows dose-related mean increases of 40-100 msec in QT and 10-40 msec in QTc. No significant alteration in QRS interval is observed.
  • In a small study (n=25) of patients with implanted defibrillators treated concurrently with sotalol, the average defibrillatory threshold was 6 joules (range 2-15 joules) compared to a mean of 16 joules for a nonrandomized comparative group primarily receiving amiodarone.
  • Twenty-five children in an unblinded, multicenter trial with supraventricular tachycardias (SVT) and/or ventricular tachyarrhythmias (VT), aged between 3 days and 12 years (mostly neonates and infants), received an ascending titration regimen with daily doses of 30, 90 and 210 mg/m2 with dosing every 8 hours for a total 9 doses. During steady-state, the respective average increases above baseline of the QTc interval, in msec (%), were 2(+1%), 14(+4%) and 29(+7%) msec at the 3 dose levels. The respective mean maximum increases above baseline of the QTc interval, in msec (%), were 23(+6%), 36(+9%) and 55(+14%) msec at the 3 dose levels. The steadystate percent increases in the RR interval were 3, 9 and 12%. The smallest children (BSA<0.33m2) showed a tendency for larger Class III effects (ΔQTc) and an increased frequency of prolongations of the QTc interval as compared with larger children (BSA≥0.33m2). The beta-blocking effects also tended to be greater in the smaller children (BSA<0.33m2). Both the Class III and beta-blocking effects of sotalol were linearly related with the plasma concentrations.

|PK=* In healthy subjects, the oral bioavailability of sotalol hydrochloride is 90-100%. After oral administration, peak plasma concentrations are reached in 2.5 to 4 hours, and steady-state plasma concentrations are attained within 2-3 days (i.e., after 5-6 doses when administered twice daily). Over the dosage range 160-640 mg/day sotalol hydrochloride displays dose proportionality with respect to plasma concentrations. Distribution occurs to a central (plasma) and to a peripheral compartment, with a mean elimination half-life of 12 hours. Dosing every 12 hours results in trough plasma concentrations which are approximately one-half of those at peak.

  • Sotalol hydrochloride does not bind to plasma proteins and is not metabolized. Sotalol hydrochloride shows very little intersubject variability in plasma levels. The pharmacokinetics of the d and l enantiomers of sotalol are essentially identical. Sotalol hydrochloride crosses the blood brain barrier poorly. Excretion is predominantly via the kidney in the unchanged form, and therefore lower doses are necessary in conditions of renal impairment. Age per se does not significantly alter the pharmacokinetics of sotalol, but impaired renal function in geriatric patients can increase the terminal elimination half-life, resulting in increased drug accumulation. The absorption of sotalol hydrochloride was reduced by approximately 20% compared to fasting when it was administered with a standard meal. Since sotalol hydrochloride is not subject to first-pass metabolism, patients with hepatic impairment show no alteration in clearance of sotalol.
  • The combined analysis of two unblinded, multicenter trials (a single dose and a multiple dose study) with 59 children, aged between 3 days and 12 years, showed the pharmacokinetics of sotalol to be first order. A daily dose of 30 mg/m2 of sotalol was administered in the single dose study and daily doses of 30, 90 and 210 mg/m2 were administered q 8h in the multi-dose study. After rapid absorption with peak levels occurring on average between 2-3 hours following administration, sotalol was eliminated with a mean half life of 9.5 hours. Steady-state was reached after 1-2 days. The average peak to trough concentration ratio was 2. BSA was the most important covariate and more relevant than age for the pharmacokinetics of sotalol.The smallest children (BSA<0.33m2) exhibited a greater drug exposure (+59%) than the larger children who showed a uniform drug concentration profile. The intersubject variation for oral clearance was 22%.

|nonClinToxic=* No evidence of carcinogenic potential was observed in rats during a 24-month study at 137-275 mg/kg/day (approximately 30 times the maximum recommended human oral dose (MRHD) as mg/kg or 5 times the MRHD as mg/m2) or in mice, during a 24-month study at 4141-7122 mg/kg/ day (approximately 450-750 times the MRHD as mg/kg or 36-63 times the MRHD as mg/m2).

  • Sotalol has not been evaluated in any specific assay of mutagenicity or clastogenicity.
  • No significant reduction in fertility occurred in rats at oral doses of 1000 mg/kg/ day (approximately 100 times the MRHD as mg/kg or 9 times the MRHD as mg/m2) prior to mating, except for a small reduction in the number of offspring per litter.

|clinicalStudies======Prolongation of Time to Recurrence of Symptomatic Atrial Fibrillation/ Flutter=====

  • Sotalol hydrochloride (AF) has been studied in patients with symptomatic AFIB/AFL in two principal studies, one in patients with primarily paroxysmal AFIB/AFL, the other in patients with primarily chronic AFIB.
  • In one study, a U.S. multicenter, randomized, placebo-controlled, double-blind, dose-response trial of patients with symptomatic primarily paroxysmal AFIB/AFL, three fixed dose levels of sotalol hydrochloride (AF) (80 mg, 120 mg and 160 mg) twice daily and placebo were compared in 253 patients. In patients with reduced creatinine clearance (40-60 mL/min) the same doses were given once daily. Patients were not randomized for the following reasons: QT >450 msec; creatinine clearance <40 mL/min; intolerance to beta-blockers; bradycardia-tachycardia syndrome in the absence of an implanted pacemaker; AFIB/AFL was asymptomatic or was associated with syncope, embolic CVA or TIA; acute myocardial infarction within the previous 2 months; congestive heart failure; bronchial asthma or other contraindications to beta-blocker therapy; receiving potassium losing diuretics without potassium replacement or without concurrent use of ACE-inhibitors; uncorrected hypokalemia (serum potassium <3.5 meq/L) or hypomagnesemia (serum magnesium <1.5 meq/L); received chronic oral amiodarone therapy for >1 month within previous 12 weeks; congenital or acquired long QT syndromes; history of Torsade de Pointes with other antiarrhythmic agents which increase the duration of ventricular repolarization; sinus rate <50 bpm during waking hours; unstable angina pectoris; receiving treatment with other drugs that prolong the QT interval; and AFIB/AFL associated with the Wolff-Parkinson-White syndrome (WPW). If the QT interval increased to ≥520 msec (or JT ≥430 msec if QRS >100 msec) the drug was discontinued. The patient population in this trial was 64% male, and the mean age was 62 years. No structural heart disease was present in 43% of the patients. Doses were administered once daily in 20% of the patients because of reduced creatinine clearance.
  • Sotalol hydrochloride (AF) was shown to prolong the time to the first symptomatic, ECG documented recurrence of AFIB/AFL, as well as to reduce the risk of such recurrence at both 6 and 12 months. The 120 mg dose was more effective than 80 mg, but 160 mg did not appear to have an added benefit. Note that these doses were given twice or once daily, depending on renal function. The results are shown in the figure and tables below.
This image is provided by the National Library of Medicine.
This image is provided by the National Library of Medicine.

Please note that columns do not add up to 100% due to discontinuations (D/C) for "other" reasons.

This image is provided by the National Library of Medicine.

Discontinuation because of adverse events was dose related.

  • In a second multicenter, randomized, placebo-controlled, double-blind study of 6 months duration in 232 patients with chronic AFIB, sotalol hydrochloride (AF) was titrated over a dose range from 80 mg/day to 320 mg/day. The patient population of this trial was 70% male with a mean age of 65 years. Structural heart disease was present in 49% of the patients. All patients had chronic AFIB for >2 weeks but <1 year at entry with a mean duration of 4.1 months. Patients were excluded if they had significant electrolyte imbalance, QTc >460 msec, QRS >140 msec, any degree of AV block or functioning pacemaker, uncompensated cardiac failure, asthma, significant renal disease (estimated creatinine clearance <50 mL/min), heart rate <50 bpm, myocardial infarction or open heart surgery in past 2 months, unstable angina, infective endocarditis, active pericarditis or myocarditis, ≥ 3 DC cardioversions in the past, medications that prolonged QT interval, and previous amiodarone treatment. After successful cardioversion patients were randomized to receive placebo (n=114) or sotalol hydrochloride (AF) (n=118), at a starting dose of 80 mg twice daily. If the initial dose was not tolerated it was decreased to 80 mg once daily, but if it was tolerated it was increased to 160 mg twice daily. During the maintenance period 67% of treated patients received a dose of 160 mg twice daily, and the remainder received doses of 80 mg once daily (17%) and 80 mg twice daily (16%).
  • The figure and Tables below show the results of the trial. There was a longer time to ECG-documented recurrence of AFIB and a reduced risk of recurrence at 6 months compared to placebo.
This image is provided by the National Library of Medicine.
This image is provided by the National Library of Medicine.
This image is provided by the National Library of Medicine.
Safety in Patients with Structural Heart Disease
  • In a multicenter double-blind randomized study reported by D. Julian et al, the effect of sotalol 320 mg once daily was compared with that of placebo in 1456 patients (randomized 3:2, sotalol to placebo) surviving an acute myocardial infarction (MI). Treatment was started 5 to 14 days after infarction. Patients were followed for 12 months. The mortality rate was 7.3% in the sotalol group and 8.9% in the placebo group, not a statistically significant difference. Although the results do not show evidence of a benefit of sotalol in this population, they do not show an added risk in post MI patients receiving sotalol.

|howSupplied======Sotalol Tablets=====

  • Betapace (sotalol hydrochloride); capsule-shaped light-blue scored tablets imprinted with the strength and “Betapace”, are available as follows:
  • 80 mg strength, bottle of 100 (NDC 50419-105-10)
  • 120 mg strength, bottle of 100 (NDC 50419-109-10)
  • 160 mg strength, bottle of 100 (NDC 50419-106-10)
Sotalol Vial
  • Intravenous sotalol is supplied in 10 mL vials, each containing 150 mg sotalol hydrochloride (15 mg/mL).
  • Each vial is individually packed in a carton (NDC 67457-176-10).

|storage======Sotalol Tablets=====

  • Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F).
Sotalol Vial
  • Store at 25°C (77°F) with excursions permitted to 15°-30° C (59°-86°F).
  • Protect from freezing and light

|fdaPatientInfo=* Prior to initiation of sotalol (AF) therapy, the patient should be advised to read the patient package insert and reread it each time therapy is renewed. The patient should be fully instructed on the need for compliance with the recommended dosing of sotalol (AF), the potential interactions with drugs that prolong the QT interval and other antiarrhythmics, and the need for periodic monitoring of QT and renal function to minimize the risk of serious abnormal rhythms.

Medications and Supplements

  • Assessment of patients' medication history should include all over-counter, prescription and herbal/natural preparations with emphasis on preparations that may affect the pharmacodynamics of sotalol (AF) such as other cardiac antiarrhythmic drugs, some phenothiazines, bepridil, tricyclic antidepressants and oral macrolides. Patients should be instructed to notify their health care providers of any change in over-the-counter, prescription or supplement use. If a patient is hospitalized or is prescribed a new medication for any condition, the patient must inform the health care provider of ongoing sotalol (AF) therapy. Patients should also check with their health care provider and/or pharmacist prior to taking a new over-the-counter medicine.

Electrolyte Imbalance

  • If patients experience symptoms that may be associated with electrolyte disturbances, such as excessive or prolonged diarrhea, sweating, or vomiting, or loss of appetite or thirst, these conditions should be immediately reported to their health care provider.

Dosing Schedule

  • Patients should be instructed NOT to double the next dose if a dose is missed. The next dose should be taken at the usual time.

|alcohol=Alcohol-Sotalol interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication. |brandNames=* Betapace

  • Betapace AF
  • Sorine

|lookAlike=* Sotalol - Sudafed |nlmPatientInfo=(Link to patient information page) |drugShortage=Drug Shortage }} {{#subobject:

 |Label Page=Sotalol
 |Label Name=BetapacePackage1.png

}}

{{#subobject:

 |Label Page=Sotalol
 |Label Name=BetapacePackage2.png

}}

{{#subobject:

 |Label Page=Sotalol
 |Label Name=BetapacePackage3.png

}}

{{#subobject:

 |Label Page=Sotalol
 |Label Name=SotalolIVPackage.png

}}

  1. Gooding PG, Berman E (1974). "An evaluation of sotalol, a beta-blocking agent, in patients with angina pectoris". Postgrad Med J. 50 (590): 734–6. PMC 2496011. PMID 4157126.
  2. Areskog NH, Cullhed I, Ringqvist I, Ström G (1975). "Cardiovascular and respiratory effects of the beta-adrenoceptive antagonist sotalol: studies in health, angina pectoris and obstructive lung disease". Eur J Clin Pharmacol. 8 (6): 403–8. PMID 1233240.
  3. Parvinen I, Paukkala E (1979). "Thrice-daily blood pressure readings on sotalol in the treatment of hypertension: once- versus twice-daily regimen". J Clin Pharmacol. 19 (8-9 Pt 2): 533–9. PMID 489772.