Prazosin: Difference between revisions
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::* May be due to an excessive postural [[hypotensive]] effect | ::* May be due to an excessive postural [[hypotensive]] effect | ||
::* Occasionally the [[syncopal]] episode has been preceded by a bout of severe [[tachycardia]] with [[heart rates]] of 120–160 beats per minute | ::* Occasionally the [[syncopal]] episode has been preceded by a bout of severe [[tachycardia]] with [[heart rates]] of 120–160 beats per minute | ||
::* Syncopal episodes have usually occurred within 30 to 90 minutes of the initial dose of the drug | ::* Syncopal episodes have usually occurred within 30 to 90 minutes of the initial dose of the drug | ||
If syncope occurs, the patient should be placed in the recumbent position and treated supportively as necessary. This adverse effect is self-limiting and in most cases does not recur after the initial period of therapy or during subsequent dose titration. | ::* These have often been reported in association with rapid [[dosage]] increases or the introduction of another [[antihypertensive]] drug into the regimen of a patient taking high doses of prazosin. | ||
Patients should always be started on the 1 mg capsules of | ::* The [[incidence]] of [[syncopal]] episodes is approximately 1% in patients given an initial dose of 2 mg or greater. | ||
More common than loss of consciousness are the symptoms often associated with lowering of the blood pressure, namely | ::* [[Clinical trials]] conducted during the investigational phase of this drug suggest that [[syncopal]] episodes can be minimized by limiting the initial dose of the drug to 1 mg, by subsequently increasing the [[dosage]] slowly, and by introducing any additional [[antihypertensive]] drugs into the patient's regimen with caution. | ||
::* If [[syncope]] occurs, the patient should be placed in the recumbent position and treated supportively as necessary. This adverse effect is self-limiting and in most cases does not recur after the initial period of therapy or during subsequent dose titration. | |||
:* [[Hypotension]] may develop in patients given prazosin who are also receiving a [[beta-blocker]] such as [[propranolol]]. | |||
:* Patients should always be started on the 1 mg capsules of prazosin. The 2 and 5 mg capsules are not indicated for initial therapy. | |||
:* More common than [[loss of consciousness]] are the [[symptoms]] often associated with lowering of the [[blood pressure]], namely: | |||
::* [[Dizziness]] | |||
::* [[Lightheadedness]]. | |||
:* The patient should be cautioned about these possible [[adverse effects]] and advised what measures to take should they develop. The patient should also be cautioned to avoid situations where injury could result should syncope occur during the initiation of prazosin therapy. | |||
|clinicalTrials=======Central Nervous System====== | |clinicalTrials=======Central Nervous System====== | ||
Revision as of 12:58, 30 June 2014
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]
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Overview
Prazosin is a alpha-adrenergic blocker that is FDA approved for the {{{indicationType}}} of treatment of hypertension. Common adverse reactions include orthostatic hypotension, palpitations, nausea, asthenia, dizziness, headache, lethargy and somnolence.
Adult Indications and Dosage
FDA-Labeled Indications and Dosage (Adult)
Hypertension
- Initial dose:
- 1 mg two or three times a day
- Maintenance dose:
- Dosage may be slowly increased to a total daily dose of 20 mg given in divided doses. The therapeutic dosages most commonly employed have ranged from 6 mg to 15 mg daily given in divided doses. Doses higher than 20 mg usually do not increase efficacy, however a few patients may benefit from further increases up to a daily dose of 40 mg given in divided doses. After initial titration some patients can be maintained adequately on a twice daily dosage regimen.
- Use with other drugs:
- When adding a diuretic or other antihypertensive agent, the dose of prazosin should be reduced to 1 mg or 2 mg three times a day and retitration then carried out.
- Concomitant administration of prazosin with a PDE-5 inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension; therefore, PDE-5 inhibitor therapy should be initiated at the lowest dose in patients taking prazosin.
Off-Label Use and Dosage (Adult)
Guideline-Supported Use
Benign prostatic hyperplasia
- Class of Recommendation: Class IIb[1]
- Strength of Evidence: Category B[1]
- Dosing Information/Recommendation
- (Dosage)
Dream disorder - posttraumatic stress disorder
- Class of Recommendation: Class IIb[1]
- Strength of Evidence: Category B[1]
- A 6-week open-label trial, with 5 patients, with history of exposure to civilian trauma, in a non-military environment, who subsequently developed posttraumatic stress disorder (PTSD):[2][3]
- 1 to 4 mg/day
- An 8-week open-label trial, with 4 patients, with history of combat trauma nightmares and chronic DSM-IV posttraumatic stress disorder (PTSD) with concomitant severe intractable combat trauma nightmares:[4]
- 2 to 10 mg/day
Erectile dysfunction
- Class of Recommendation: Class IIb[1]
- Strength of Evidence: Category B[1]
- Dosing Information/Recommendation
- (Dosage)
Poisoning due to scorpion venom
- Class of Recommendation: Class IIb[1]
- Strength of Evidence: Category B[1]
- Dosing Information/Recommendation
- (Dosage)
Raynaud's phenomenon
- Class of Recommendation: Class IIb[1]
- Strength of Evidence: Category B[1]
- Dosing Information/Recommendation
- (Dosage)
Non–Guideline-Supported Use
Condition 1
- Dosing Information
- (Dosage)
Condition 2
- Dosing Information
- (Dosage)
Condition 3
- Dosing Information
- (Dosage)
Pediatric Indications and Dosage
FDA-Labeled Indications and Dosage (Pediatric)
Condition 1
- Dosing Information
- (Dosage)
Condition 2
- Dosing Information
- (Dosage)
Off-Label Use and Dosage (Pediatric)
Guideline-Supported Use
Condition 1
- Developed by: (Organisation)
- Class of Recommendation: (Class) (Link)
- Strength of Evidence: (Category A/B/C) (Link)
- Dosing Information/Recommendation
- (Dosage)
Condition 2
- Developed by: (Organisation)
- Class of Recommendation: (Class) (Link)
- Strength of Evidence: (Category A/B/C) (Link)
- Dosing Information/Recommendation
- (Dosage)
Non–Guideline-Supported Use
Condition 1
- Dosing Information
- (Dosage)
Condition 2
- Dosing Information
- (Dosage)
Condition 3
- Dosing Information
- (Dosage)
Contraindications
- Prazosin is contraindicated in patients with known sensitivity to:
- Quinazolines
- Prazosin
- Any of the inert ingredients
Warnings
- Prazosin, as other alpha-blockers, may cause:
- Syncope with sudden loss of consciousness:
- May be due to an excessive postural hypotensive effect
- Occasionally the syncopal episode has been preceded by a bout of severe tachycardia with heart rates of 120–160 beats per minute
- Syncopal episodes have usually occurred within 30 to 90 minutes of the initial dose of the drug
- These have often been reported in association with rapid dosage increases or the introduction of another antihypertensive drug into the regimen of a patient taking high doses of prazosin.
- The incidence of syncopal episodes is approximately 1% in patients given an initial dose of 2 mg or greater.
- Clinical trials conducted during the investigational phase of this drug suggest that syncopal episodes can be minimized by limiting the initial dose of the drug to 1 mg, by subsequently increasing the dosage slowly, and by introducing any additional antihypertensive drugs into the patient's regimen with caution.
- If syncope occurs, the patient should be placed in the recumbent position and treated supportively as necessary. This adverse effect is self-limiting and in most cases does not recur after the initial period of therapy or during subsequent dose titration.
- Hypotension may develop in patients given prazosin who are also receiving a beta-blocker such as propranolol.
- Patients should always be started on the 1 mg capsules of prazosin. The 2 and 5 mg capsules are not indicated for initial therapy.
- More common than loss of consciousness are the symptoms often associated with lowering of the blood pressure, namely:
- The patient should be cautioned about these possible adverse effects and advised what measures to take should they develop. The patient should also be cautioned to avoid situations where injury could result should syncope occur during the initiation of prazosin therapy.
Adverse Reactions
Clinical Trials Experience
Central Nervous System
- (list/description of adverse reactions)
Cardiovascular
- (list/description of adverse reactions)
Respiratory
- (list/description of adverse reactions)
Gastrointestinal
- (list/description of adverse reactions)
Hypersensitive Reactions
- (list/description of adverse reactions)
Miscellaneous
- (list/description of adverse reactions)
Condition 2
Central Nervous System
- (list/description of adverse reactions)
Cardiovascular
- (list/description of adverse reactions)
Respiratory
- (list/description of adverse reactions)
Gastrointestinal
- (list/description of adverse reactions)
Hypersensitive Reactions
- (list/description of adverse reactions)
Miscellaneous
- (list/description of adverse reactions)
Postmarketing Experience
(Description)
Drug Interactions
- Drug 1
- Drug 2
- Drug 3
- Drug 4
- Drug 5
Drug 1
(Description)
Drug 2
(Description)
Drug 3
(Description)
Drug 4
(Description)
Drug 5
(Description)
Use in Specific Populations
Pregnancy
Pregnancy Category (FDA):
(Description)
Pregnancy Category (AUS):
(Description)
Labor and Delivery
(Description)
Nursing Mothers
(Description)
Pediatric Use
(Description)
Geriatic Use
(Description)
Gender
(Description)
Race
(Description)
Renal Impairment
(Description)
Hepatic Impairment
(Description)
Females of Reproductive Potential and Males
(Description)
Immunocompromised Patients
(Description)
Others
(Description)
Administration and Monitoring
Administration
(Oral/Intravenous/etc)
Monitoring
Condition 1
(Description regarding monitoring, from Warnings section)
Condition 2
(Description regarding monitoring, from Warnings section)
Condition 3
(Description regarding monitoring, from Warnings section)
IV Compatibility
Solution
Compatible
- Solution 1
- Solution 2
- Solution 3
Not Tested
- Solution 1
- Solution 2
- Solution 3
Variable
- Solution 1
- Solution 2
- Solution 3
Incompatible
- Solution 1
- Solution 2
- Solution 3
Y-Site
Compatible
- Solution 1
- Solution 2
- Solution 3
Not Tested
- Solution 1
- Solution 2
- Solution 3
Variable
- Solution 1
- Solution 2
- Solution 3
Incompatible
- Solution 1
- Solution 2
- Solution 3
Admixture
Compatible
- Solution 1
- Solution 2
- Solution 3
Not Tested
- Solution 1
- Solution 2
- Solution 3
Variable
- Solution 1
- Solution 2
- Solution 3
Incompatible
- Solution 1
- Solution 2
- Solution 3
Syringe
Compatible
- Solution 1
- Solution 2
- Solution 3
Not Tested
- Solution 1
- Solution 2
- Solution 3
Variable
- Solution 1
- Solution 2
- Solution 3
Incompatible
- Solution 1
- Solution 2
- Solution 3
TPN/TNA
Compatible
- Solution 1
- Solution 2
- Solution 3
Not Tested
- Solution 1
- Solution 2
- Solution 3
Variable
- Solution 1
- Solution 2
- Solution 3
Incompatible
- Solution 1
- Solution 2
- Solution 3
Overdosage
Acute Overdose
Signs and Symptoms
(Description)
Management
(Description)
Chronic Overdose
Signs and Symptoms
(Description)
Management
(Description)
Pharmacology
Prazosin
| |
| Systematic (IUPAC) name | |
| ? | |
| Identifiers | |
| CAS number | ? |
| ATC code | ? |
| PubChem | ? |
| Chemical data | |
| Formula | ? |
| Mol. mass | ? |
| Pharmacokinetic data | |
| Bioavailability | ? |
| Metabolism | ? |
| Half life | ? |
| Excretion | ? |
| Therapeutic considerations | |
| Pregnancy cat. |
? |
| Legal status | |
| Routes | ? |
Mechanism of Action
(Description)
Structure
(Description with picture)
Pharmacodynamics
(Description)
Pharmacokinetics
(Description)
Nonclinical Toxicology
(Description)
Clinical Studies
Condition 1
(Description)
Condition 2
(Description)
Condition 3
(Description)
How Supplied
(Description)
Storage
There is limited information regarding Prazosin Storage in the drug label.
Images
Drug Images
{{#ask: Page Name::Prazosin |?Pill Name |?Drug Name |?Pill Ingred |?Pill Imprint |?Pill Dosage |?Pill Color |?Pill Shape |?Pill Size (mm) |?Pill Scoring |?NDC |?Drug Author |format=template |template=DrugPageImages |mainlabel=- |sort=Pill Name }}
Package and Label Display Panel
{{#ask: Label Page::Prazosin |?Label Name |format=template |template=DrugLabelImages |mainlabel=- |sort=Label Page }}
Patient Counseling Information
(Patient Counseling Information)
Precautions with Alcohol
Alcohol-Prazosin interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.
Brand Names
There is limited information regarding Prazosin Brand Names in the drug label.
Look-Alike Drug Names
- (Paired Confused Name 1a) — (Paired Confused Name 1b)
- (Paired Confused Name 2a) — (Paired Confused Name 2b)
- (Paired Confused Name 3a) — (Paired Confused Name 3b)
Drug Shortage Status
Drug Shortage
Price
References
The contents of this FDA label are provided by the National Library of Medicine.
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 "PRAZOSIN".
- ↑ Raskind MA, Thompson C, Petrie EC, Dobie DJ, Rein RJ, Hoff DJ; et al. (2002). "Prazosin reduces nightmares in combat veterans with posttraumatic stress disorder". J Clin Psychiatry. 63 (7): 565–8. PMID 12143911.
- ↑ Taylor F, Raskind MA (2002). "The alpha1-adrenergic antagonist prazosin improves sleep and nightmares in civilian trauma posttraumatic stress disorder". J Clin Psychopharmacol. 22 (1): 82–5. PMID 11799347.
- ↑ Raskind MA, Dobie DJ, Kanter ED, Petrie EC, Thompson CE, Peskind ER (2000). "The alpha1-adrenergic antagonist prazosin ameliorates combat trauma nightmares in veterans with posttraumatic stress disorder: a report of 4 cases". J Clin Psychiatry. 61 (2): 129–33. PMID 10732660.