Methyldopa: Difference between revisions
No edit summary |
No edit summary |
||
| Line 59: | Line 59: | ||
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, 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If methyldopa is abruptly withdrawn, rebound hypertension happens.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. | If methyldopa is abruptly withdrawn, rebound hypertension happens.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.<ref name="dailymed.nlm.nih.gov">{{Cite web | last = | first = | title = METHYLDOPA TABLET [CARDINAL HEALTH] | url = http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=d87d63fd-48f7-4130-af03-5e263c338fe4 | publisher = | date = | accessdate = 10 March 2014 }}</ref> | ||
==References== | ==References== | ||
Revision as of 23:07, 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.[1]
References
- ↑ "METHYLDOPA TABLET [CARDINAL HEALTH]". Retrieved 10 March 2014.