Methyldopa

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Methyldopa
Skeletal formula of methyldopa
Ball-and-stick model of the methyldopa molecule
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[1]
Biological half-life 105 minutes
Duration of action 10 to 48 hrs[1]
Excretion Kidney for metabolites
Identifiers
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
ChEMBL
ECHA InfoCard 100.008.264
Chemical and physical data
Formula C10H13NO4
Molar mass 211.215 g/mol
3D model (JSmol)
 NYesY (what is this?)  (verify)

Methyldopa, sold under the brand name Aldomet among others, is a medication used for high blood pressure.[1] It is one of the preferred treatments for high blood pressure in pregnancy.[1] For other types of high blood pressure including very high blood pressure resulting in symptoms other medications are typically preferred.[1] It can be given by mouth or injection into a vein.[1] Onset of effects is around 5 hours and they last about a day.[1]

Common side effects include sleepiness.[1] More severe side effects include red blood cell breakdown, liver problems, and allergic reactions.[1] Methyldopa is in the alpha-2 adrenergic receptor agonist family of medication.[1] It works by stimulating the brain to decrease the activity of the sympathetic nervous system.[1]

Methydopa was discovered in 1960,[2] it is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.[3] The wholesale cost in the developing world is about 4.31 to 9.48 USD per month.[4] In the United States it costs less than 25 USD per month.[5]

Medical uses[edit]

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

Side effects[edit]

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.[6] Side effects may include:

Rebound/withdrawal[edit]

Rebound hypertension via withdrawal on account of tolerance upon the abrupt discontinuation of methyldopa has been reported.[7]

Mechanism of action[edit]

Methyldopa has a dual mechanism of action:

Pharmacokinetics[edit]

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

History[edit]

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.[8] 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.

See also[edit]

References[edit]

  1. ^ a b c d e f g h i j k "Methyldopa". The American Society of Health-System Pharmacists. Archived from the original on 21 December 2016. Retrieved 8 December 2016. 
  2. ^ Walker, S. R. (2012). Trends and Changes in Drug Research and Development. Springer Science & Business Media. p. 109. ISBN 9789400926592. Archived from the original on 2016-09-14. 
  3. ^ "WHO Model List of Essential Medicines (19th List)" (PDF). World Health Organization. April 2015. Archived (PDF) from the original on 13 December 2016. Retrieved 8 December 2016. 
  4. ^ "Methyldopa". International Drug Price Indicator Guide. Retrieved 8 December 2016. 
  5. ^ Hamilton, Richart (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 140. ISBN 9781284057560. 
  6. ^ British National Formulary 56. September 2008. pp. 95–96. ISBN 978-0-85369-778-7. 
  7. ^ Methyldopa (PIM 342) Archived 2008-03-13 at the Wayback Machine.
  8. ^ Mah GT, Tejani AM, Musini VM. Methyldopa for primary hypertension. Cochrane Database of Systematic Reviews 2009, Issue 4. Art. No.: CD003893. DOI: 10.1002/14651858.CD003893.pub3.

External links[edit]