Methyldopa

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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.[1]

References

  1. "METHYLDOPA TABLET [CARDINAL HEALTH]". Retrieved 10 March 2014.