Methyldopa Clinical data Trade names Aldomet, Aldoril, Dopamet, others Synonyms L-α-Methyl-3,4-dihydroxyphenylalanine AHFS/ Drugs.com Monograph MedlinePlus a682242 Pregnancy category
AU: A US: B (No risk in non-human studies) Routes of administration by mouth, IV ATC code Legal status Legal status
Pharmacokinetic data Bioavailability approximately 50% Metabolism Liver Onset of action 4 to 6 hrs  Elimination half-life 105 minutes Duration of action 10 to 48 hrs  Excretion Kidney for metabolites Identifiers
( S)-2-amino-3-(3,4-dihydroxyphenyl)-2-methyl-propanoic acid CAS Number PubChem CID IUPHAR/BPS DrugBank ChemSpider UNII ChEMBL CompTox Dashboard ( EPA) ECHA InfoCard 100.008.264 Chemical and physical data Formula C 10 H 13 N O 4 Molar mass 211.215 g/mol g·mol −1 3D model ( JSmol)
(what is this?) (verify) Methyldopa, sold under the brand name Aldomet among others, is a medication used for high blood pressure. It is one of the preferred treatments for  high blood pressure in pregnancy. For other types of high blood pressure including  very high blood pressure resulting in symptoms other medications are typically preferred. It can be given by mouth or  injection into a vein. Onset of effects is around 5 hours and they last about a day. 
Common side effects include sleepiness.
More severe side effects include  red blood cell breakdown, liver problems, and allergic reactions. Methyldopa is in the  alpha-2 adrenergic receptor agonist family of medication. It works by stimulating the brain to decrease the activity of the  sympathetic nervous system.
Methyldopa was discovered in 1960.
It is on the  World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The wholesale cost in the  developing world is about US$4.31–9.48 per month. In the United States it costs less than $25 per month. 
Methyldopa is used in the
clinical treatment of the following disorders:
Methyldopa is capable of inducing a number of adverse side effects, which range from mild to severe. Nevertheless, they are generally mild when the dose is less than 1 gram per day.
Side effects may include:
Depression or even suicidal ideation, as well as nightmares
Apathy or anhedonia, as well as dysphoria
Anxiety, especially of the social anxiety variant Decreased
alertness, awareness, and wakefulness Impaired
attention, focus, and concentration Decreased
desire, drive, and motivation
Fatigue or lethargy or malaise or lassitude
Sedation or drowsiness or somnolence or sleepiness
Agitation or restlessness
Cognitive and memory impairment
Derealization or depersonalization, as well as mild psychosis Sexual dysfunction including impaired libido, desire, and drive Physiological
Dizziness, lightheadedness, or vertigo
Miosis or pupil constriction
Xerostomia or dry mouth
Gastrointestinal disturbances such as diarrhea or constipation
Headache or migraine
Myalgia or muscle aches, arthralgia or joint pain, or paresthesia ("pins and needles")
Restless legs syndrome (RLS)
Parkinsonian symptoms such as muscle tremors, rigidity, hypokinesia, or balance or postural instability
Akathisia, ataxia, dyskinesia as well as even tardive dyskinesia, or dystonia
Bell's palsy or facial paralysis
Sexual dysfunction consisting of impaired erectile dysfunction or anorgasmia
Hyperprolactinemia or excess prolactin, gynecomastia/breast enlargement in males, or amenorrhoea or absence of menstrual cycles in females
Bradycardia or decreased heart rate
Hypotension or decreased blood pressure (though this may also be considered a therapeutic benefit)
Orthostatic hypotension (also known as postural hypotension)
Hepatitis, hepatotoxicity, or liver dysfunction or damage
Pancreatitis or inflammation of the pancreas
Warm autoimmune hemolytic anemia or deficiency in red blood cells (RBCs)
Myelotoxicity or bone marrow suppression, potentially leading to thrombocytopenia or blood platelet deficiency or leukopenia or white blood cell (WBC) deficiency
Hypersensitivity such as lupus erythematosus, myocarditis, or pericarditis
Lichenoid reactions such as skin lesions or rashes Pallor
Rebound hypertension via withdrawal on account of tolerance upon the abrupt discontinuation of methyldopa has been reported.
Mechanism of action
Methyldopa has a dual
mechanism of action:
Methyldopa exhibits variable
absorption from the gastrointestinal tract. It is metabolized in the liver and intestines and is excreted in urine.
When methyldopa was first introduced, it was the mainstay of antihypertensive
treatment, but its use has declined on account of relatively severe adverse side effects, with increased use of other safer and more tolerable agents such as alpha blockers, beta blockers, and calcium channel blockers. Additionally, it has yet to be associated with reducing adverse cardiovascular events including myocardial infarction and stroke, or overall all-cause mortality reduction in clinical trials. Nonetheless, one of methyldopa's still current indications is in the management of  pregnancy-induced hypertension (PIH), as it is relatively safe in pregnancy compared to many other antihypertensives which may affect the fetus.
(levodopa; trade names Sinemet, Pharmacopa, Atamet, Stalevo, Madopar, Prolopa, etc.) L-DOPA
Dopamine (Intropan, Inovan, Revivan, Rivimine, Dopastat, Dynatra, etc.)
Norepinephrine (noradrenaline; Levophed, etc.) Epinephrine (adrenaline; Adrenalin, EpiPed, Twinject, etc.)
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