Methyldopa


Methyldopa
Methyldopa
Systematic (IUPAC) name
(S)-2-amino-3-(3,4-dihydroxyphenyl)-2-methyl-propanoic acid
Clinical data
AHFS/Drugs.com monograph
MedlinePlus a682242
Pregnancy cat. a drug of choice in PIH
Legal status Prescription only
Routes Oral, IV
Pharmacokinetic data
Bioavailability approximately 50%
Metabolism Hepatic
Half-life 105 minutes
Excretion Renal for metabolites
Identifiers
CAS number 555-30-6 YesY
ATC code C02AB01
PubChem CID 40175
DrugBank APRD01106
ChemSpider 36713 YesY
UNII 56LH93261Y YesY
ChEMBL CHEMBL459 N
Chemical data
Formula C10H13NO4 
Mol. mass 211.215 g/mol
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Methyldopa (L-α-Methyl-3,4-dihydroxyphenylalanine; Aldomet, Aldoril, Dopamet, Dopegyt, etc.) is an alpha-adrenergic agonist (selective for α2-adrenergic receptors) psychoactive drug used as a sympatholytic or antihypertensive. Its use is now mostly deprecated following the introduction of alternative safer classes of agents. However, it continues to have a role in otherwise difficult to treat hypertension and gestational hypertension (also known as pregnancy-induced hypertension (PIH)).

Contents

Indications

Methyldopa is used in the clinical treatment of the following disorders:

Pharmacology

Methyldopa has a dual mechanism of action:

  • It is converted to α-methylnorepinephrine by dopamine beta-hydroxylase (DBH). α-methylnorepinephrine is an agonist of presynaptic central nervous system α2-adrenergic receptors. Activation of these receptors in the brainstem appears to inhibit sympathetic nervous system output and lower blood pressure. This is also the mechanism of action of clonidine.

Pharmacokinetics

Methyldopa exhibits variable absorption from the gastrointestinal tract. It is metabolized in the liver and intestines and is excreted in urine.

History

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. 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.

Side effects

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.[1] Side effects may include:

Rebound/withdrawal

Rebound hypertension via withdrawal on account of tolerance upon the abrupt discontinuation of methyldopa has been reported.[2]

See also

  • D-DOPA (Dextrodopa)
  • L-DOPA (Levodopa; Sinemet, Parcopa, Atamet, Stalevo, Madopar, Prolopa, etc.)
  • L-DOPS (Droxidopa)
  • Dopamine (Intropan, Inovan, Revivan, Rivimine, Dopastat, Dynatra, etc.)
  • Norepinephrine (Noradrenaline; Levophed, etc.)
  • Epinephrine (Adrenaline; Adrenalin, EpiPed, Twinject, etc.)

References

  1. ^ British National Formulary 56. September 2008. p. 95–96. ISBN 978-0-85369-778-7. 
  2. ^ Methyldopa (PIM 342)



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Look at other dictionaries:

  • Méthyldopa — Général Nom IUPAC acide (S) 2 amino 3 (3,4 dihydroxyphenyl) 2 methyl propanoïque …   Wikipédia en Français

  • Methyldopa — Strukturformel Allgemeines Name Methyldopa …   Deutsch Wikipedia

  • methyldopa — metildopa statusas T sritis chemija formulė (HO)₂C₆H₃CH₂(CH₃)C(NH₂)COOH atitikmenys: angl. methyldopa rus. метилдофа ryšiai: sinonimas – 2 amino 3 (3,4 dihidroksifenil) 2 metilpropano rūgštis …   Chemijos terminų aiškinamasis žodynas

  • methyldopa — noun Date: 1954 a drug C10H13NO4 used to lower blood pressure …   New Collegiate Dictionary

  • Methyldopa — МЕТИЛДОФА ( Меthyldopа )*. ( )3 (3,4 Диоксифенил) 2 метилаланин, или 3 оксиa метилL тирозин. Синонимы: А льдомет (Hазвание препарата фирмы MERCK CO., INC. , Rahway, N. J., U. S. A.), Допегит, Aldomet, Aldomin, Alfamet, Dopamet, Dopatec, Hypotonal …   Словарь медицинских препаратов

  • methyldopa — An antihypertensive drug, preferred in pregnant patients …   Dictionary of molecular biology

  • methyldopa — /meth euhl doh peuh/, n. Pharm. a white powder, C10H13NO4, used in the treatment of hypertension. [1950 55; METHYL + DOPA] * * * …   Universalium

  • methyldopa — noun A psychoactive drug used as a sympatholytic or antihypertensive …   Wiktionary

  • methyldopa — An antihypertensive agent, also used as the ethyl ester hydrochloride, with the same action and uses. SYN: alpha methyl dopa. * * * meth·yl·do·pa .meth əl dō pə n an antihypertensive drug C10H13NO4 * * * n …   Medical dictionary

  • methyldopa — n. a drug that acts on receptors in the brain to reduce blood pressure. It is administered by mouth or injection, and drowsiness commonly occurs during the first days of treatment. Trade names: Aldomet …   The new mediacal dictionary


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