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{{drugbox |
__NOTOC__
| IUPAC_name = 2-amino-3-(3,4-dihydroxyphenyl)-2-methyl-propanoic acid
{{Methyldopa}}
| image = Methyldopa_svg.png
{{CMG}}; {{AE}}
| CAS_number = 555-30-6
| ATC_prefix = C02
| ATC_suffix = AB01
| PubChem = 4138
| DrugBank = APRD01106
| C = 10 | H = 13 | N = 1 | O = 4
| molecular_weight = 211.215 g/mol
| bioavailability = approximately 50%
| metabolism = [[Liver|Hepatic]]
| elimination_half-life = 105 minutes
| excretion = [[Kidney|Renal]] for metabolites
| pregnancy_category = a drug of choice in [[Pregnancy-induced hypertension|PIH]]
| legal_status = Rx-only
| routes_of_administration = Oral, [[intravenous|IV]]
}}
{{SI}}
{{CMG}}


'''''For patient information about Methyldopa, click [[Methyldopa (patient information)|here]].'''''


{{SB}}
Methylodopa<sup>®</sup>


==Overview==
'''Methyldopa''' or '''alpha-methyldopa''' (brand names '''Aldomet®''', '''Apo-Methyldopa®''', '''Dopamet®''', '''Novomedopa®''') is a centrally-acting adrenergic [[antihypertensive]] medication. Its use is now deprecated following introduction of alternative safer classes of agents. However it continues to have a role in otherwise difficult to treat hypertension and [[pregnancy-induced hypertension]].
'''Methyldopa''' or '''alpha-methyldopa''' (brand names '''Aldomet®''', '''Apo-Methyldopa®''', '''Dopamet®''', '''Novomedopa®''') is a centrally-acting adrenergic [[antihypertensive]] medication. Its use is now deprecated following introduction of alternative safer classes of agents. However it continues to have a role in otherwise difficult to treat hypertension and [[pregnancy-induced hypertension]].
==Category==


==Mechanism of action==
==FDA Package Insert==
Methyldopa has variable absorption from the gut of approximately 50%. It is metabolized in the [[intestine]]s and [[liver]]; its metabolite alpha-methylnorepineprine acts in the [[brain]] to stimulate [[alpha-adrenergic receptor]]s decreasing [[total peripheral resistance]]. It is [[excretion|excreted]] in [[urine]].


Methyldopa, in its active metabolite form, leads to increased alpha-2 receptor-mediated inhibition of SNS (centrally and peripherally), allowing PSNS tone to increase. Such activity leads to a decrease in total peripheral resistance (TPR) and [[cardiac output]].
====Methyldopa tablet<sup>®</sup>====


If methyldopa is abruptly withdrawn, rebound hypertension happens. This results because the long term use of methyldopa lowers the sensitivity of presynaptic alpha 2 receptors: the release of [[norepinephrine]] (NE) from sympathetic nerve endings is modulated by NE itself acting on the  presynaptic alpha 2 autoreceptors thus inhibiting its own release. The discontinuation of methyldopa removes the inhibition on NE release leading to excessive NE release from the SNS and the rebound hypertension.


==History==
'''  [[Methyldopa tablet indications and usage|Indications and Usage]]'''
When introduced it was a mainstay of antihypertensive therapy, but its use has declined, with increased use of other safer classes of agents. One of its important present-day uses is in the management of [[pregnancy-induced hypertension]], as it is relatively safe in pregnancy compared to other antihypertensive drugs.
'''| [[Methyldopa tablet dosage and administration|Dosage and Administration]]'''
'''| [[Methyldopa tablet dosage forms and strengths|Dosage Forms and Strengths]]'''
'''| [[Methyldopa tablet contraindications|Contraindications]]'''
'''| [[Methyldopa tablet warnings |Warnings ]]'''
'''| [[Methyldopa tablet precautions| Precautions]]'''
'''| [[Methyldopa tablet adverse reactions|Adverse Reactions]]'''
'''| [[Methyldopa tablet drug interactions|Drug Interactions]]'''
'''| [[Methyldopa tablet use in specific populations|Use in Specific Populations]]'''
'''| [[Methyldopa tablet overdosage|Overdosage]]'''
'''| [[Methyldopa tablet description|Description]]'''
'''| [[Methyldopa tablet clinical pharmacology|Clinical Pharmacology]]'''
'''| [[Methyldopa tablet nonclinical toxicology|Nonclinical Toxicology]]'''
'''| [[Methyldopa tablet clinical studies|Clinical Studies]]'''
'''| [[Methyldopa tablet how supplied storage and handling|How Supplied/Storage and Handling]]'''
'''| [[Methyldopa tablet patient counseling information|Patient Counseling Information]]'''
'''| [[Methyldopa tablet labels and packages|Labels and Packages]]'''


==Side effects==
====Methyldopa injection<sup>®</sup>====
There are many possible reported side-effects with some, whilst rare, being serious. Side effects are usually fewer if the dose is less than 1 g per day:<!--
'''  [[Methyldopa injection indications and usage|Indications and Usage]]'''
  --><ref>[[British National Formulary]] ''45'' March 2003</ref>
'''| [[Methyldopa injection dosage and administration|Dosage and Administration]]'''
* Gastro-intestinal disturbances
'''| [[Methyldopa injection dosage forms and strengths|Dosage Forms and Strengths]]'''
* Dry mouth
'''| [[Methyldopa injection contraindications|Contraindications]]'''
* [[Bradycardia]] (slow pulse rate)
'''| [[Methyldopa injection warnings| Warnings]]'''
* Worsening of [[Angina pectoris|angina]]
'''| [[Methyldopa injection precautions|Precautions]]'''
* [[Orthostatic hypotension]] (Postural hypotension)
'''| [[Methyldopa injection adverse reactions|Adverse Reactions]]'''
* Sedation, headaches, dizziness
'''| [[Methyldopa injection drug interactions|Drug Interactions]]'''
* [[Myalgia]] (muscle pain), [[arthralgia]] (joint pain) or [[paraesthesia]] (numbness)
'''| [[Methyldopa injection use in specific populations|Use in Specific Populations]]'''
* Nightmares, mild [[psychosis]], [[depression (mood)|depression]]
'''| [[Methyldopa injection overdosage|Overdosage]]'''
* [[Parkinsonism]]
'''| [[Methyldopa injection description|Description]]'''
* [[Bell's palsy]]
'''| [[Methyldopa injection clinical pharmacology|Clinical Pharmacology]]'''
* Abnormal liver functions tests and [[hepatitis]]
'''| [[Methyldopa injection nonclinical toxicology|Nonclinical Toxicology]]'''
* [[Pancreatitis]]
'''| [[Methyldopa injection clinical studies|Clinical Studies]]'''
* [[Haemolytic anaemia]]
'''| [[Methyldopa injection how supplied storage and handling|How Supplied/Storage and Handling]]'''
* Bone marrow suppresion leading to [[thrombocytopenia]] (low platelets) or [[leukopenia|leucopenia]] (low white blood cells)
'''| [[Methyldopa injection patient counseling information|Patient Counseling Information]]'''
* Hypersensitivity reactions including [[lupus erythematosus]]-like syndrome, myocarditis (heart muscle inflammation), [[pericarditis]] and rashes
'''| [[Methyldopa injection labels and packages|Labels and Packages]]'''
* Ejaculatory failure, Impotence, decreased libido, [[gynecomastia]] (breast enlargement in men), [[hyperprolactinaemia]] and [[amenorrhoea]]
* '''Note that if used in pregnant women, it may cause a positive [[Coombs test]]'''


==Footnotes==
==Mechanism of action==
<references/>
Methyldopa has variable absorption from the gut of approximately 50%. It is metabolized in the [[intestine]]s and [[liver]]; its metabolite alpha-methylnorepineprine acts in the [[brain]] to stimulate [[alpha-adrenergic receptor]]s decreasing [[total peripheral resistance]]. It is [[excretion|excreted]] in [[urine]].


Methyldopa, in its active metabolite form, leads to increased alpha-2 receptor-mediated inhibition of SNS (centrally and peripherally), allowing PSNS tone to increase. Such activity leads to a decrease in total peripheral resistance (TPR) and [[cardiac output]].


If methyldopa is abruptly withdrawn, rebound hypertension happens. This results because the long term use of methyldopa lowers the sensitivity of presynaptic alpha 2 receptors: the release of [[norepinephrine]] (NE) from sympathetic nerve endings is modulated by NE itself acting on the  presynaptic alpha 2 autoreceptors thus inhibiting its own release. The discontinuation of methyldopa removes the inhibition on NE release leading to excessive NE release from the SNS and the rebound hypertension.


{{Antihypertensives and diuretics}}
==References==


[[de:Methyldopa]]
{{Reflist|2}}
[[hr:Metildopa]]
[[ru:Метилдофа]]
[[sv:Metyldopa]]


[[Category:Antihypertensive agents]]
[[Category:Cardiovascular Drugs]]
[[Category:Hepatitis]]
[[Category:Drugs]]
[[Category:Drugs]]
[[pl:Metyldopa]]
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{{WikiDoc Sources}}

Revision as of 23:06, 12 March 2014

Methyldopa
Methyldopa tablet® FDA Package Insert
Indications and Usage
Dosage and Administration
Contraindications
Warnings
Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Overdosage
Description
Clinical Pharmacology
Nonclinical Toxicology
How Supplied/Storage and Handling
Labels and Packages
Methyldopa injection® FDA Package Insert
Indications and Usage
Dosage and Administration
Contraindications
Warnings
Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Overdosage
Description
Clinical Pharmacology
Nonclinical Toxicology
How Supplied/Storage and Handling
Labels and Packages
Clinical Trials on Methyldopa
ClinicalTrials.gov

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:

For patient information about Methyldopa, click here.

Synonyms / Brand Names: Methylodopa®

Overview

Methyldopa or alpha-methyldopa (brand names Aldomet®, Apo-Methyldopa®, Dopamet®, Novomedopa®) is a centrally-acting adrenergic antihypertensive medication. Its use is now deprecated following introduction of alternative safer classes of agents. However it continues to have a role in otherwise difficult to treat hypertension and pregnancy-induced hypertension.

Category

FDA Package Insert

Methyldopa tablet®

Indications and Usage | Dosage and Administration | Dosage Forms and Strengths | Contraindications | Warnings | Precautions | Adverse Reactions | Drug Interactions | Use in Specific Populations | Overdosage | Description | Clinical Pharmacology | Nonclinical Toxicology | Clinical Studies | How Supplied/Storage and Handling | Patient Counseling Information | Labels and Packages

Methyldopa injection®

Indications and Usage | Dosage and Administration | Dosage Forms and Strengths | Contraindications | Warnings | Precautions | Adverse Reactions | Drug Interactions | Use in Specific Populations | Overdosage | Description | Clinical Pharmacology | Nonclinical Toxicology | Clinical Studies | How Supplied/Storage and Handling | Patient Counseling Information | Labels and Packages

Mechanism of action

Methyldopa has variable absorption from the gut of approximately 50%. It is metabolized in the intestines and liver; its metabolite alpha-methylnorepineprine acts in the brain to stimulate alpha-adrenergic receptors decreasing total peripheral resistance. It is excreted in urine.

Methyldopa, in its active metabolite form, leads to increased alpha-2 receptor-mediated inhibition of SNS (centrally and peripherally), allowing PSNS tone to increase. Such activity leads to a decrease in total peripheral resistance (TPR) and cardiac output.

If methyldopa is abruptly withdrawn, rebound hypertension happens. This results because the long term use of methyldopa lowers the sensitivity of presynaptic alpha 2 receptors: the release of norepinephrine (NE) from sympathetic nerve endings is modulated by NE itself acting on the presynaptic alpha 2 autoreceptors thus inhibiting its own release. The discontinuation of methyldopa removes the inhibition on NE release leading to excessive NE release from the SNS and the rebound hypertension.

References

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