//fpnotebook.com/
Methyl-Dopa
Aka: Methyl-Dopa, Methyldopa, Alpha Methyldopa, Aldomet
- See Also
- Alpha Adrenergic Central Agonist
- Clonidine
- Guanabenz (Wytensin)
- Guanfacine (Tenex)
- Indications
- Hypertension in Pregnancy
- Safety
- Long safety record in pregnancy
- Disadvantages
- Weak antihypertensive
- Less tolerated (Fatigue, Dizziness) than other agents
- Contraindications
- Significant Liver Disease
- Pharmacokinetics
- Renal excretion (metabolized or 63% as unchanged in urine)
- Dosing: Hypertension in Pregnancy
- Start: 250 mg orally twice to three times daily
- Maintenance: 500 mg orally twice daily
- Maximum: Up to 3000 mg daily in divided doses
- Dosing: Hypertensive Crisis
- Start: 250-500 mg IV every 6 hours (up to 1000 mg every 6 hours)
- Dosing: Pediatric Hypertension
- Dose: 10 mg/kg/day divided bid to qid
- Maximum: 65 mg/kg/day up to 3000 mg/day in divided doses
- Mechanism
- See Alpha Adrenergic Central Agonist
- See Alpha Adrenergic Receptor
- Central Acting Adrenergic Agonist
- Activates alpha-2 receptors that inhibit CNS sympathetic signals (similar to Clonidine)
- Results in increased parasympathetic effects and side effects
- Methylnorepinephrine (Methyldopa) metabolite
- Weak Sympathomimetic that also decreases CNS sympathetic outflow
- Adverse Effects
- Somnolence
- Dry Mouth
- Orthostatic Hypotension or Dizziness
- Erectile Dysfunction
- Nightmares
- Involuntary movements
- Hepatotoxicity
- Sodium and water retention
- Reflex renin release in response to excessive Clonidine and renal hypoperfusion
- Discontinue for Congestive Heart Failure signs
- Hemolytic Anemia (rare, serious)
- Monitor Complete Blood Count
-
Drug Interactions
- Tricyclic Antidepressants
- Decreased Clonidine antihypertensive effect
- CNS Depressants (e.g. Alcohol, Benzodiazepines, Barbiturates)
- Increase Clonidine related CNS effects (e.g. Somnolence)
- References
- Olson (2020) Clinical Pharmacology, MedMaster, Miami, p. 64-5
- Hamilton (2010) Tarascon Pocket Pharmacopeia, Jones and Bartlett, p. 76