Methyldopa is an alpha-adrenergic agonist

Alpha-adrenergic agonist

An adrenergic alpha-agonist is a drug that selectively stimulates alpha adrenergic receptors. The alpha-adrenergic receptor has two subclasses α1 and α2.-Classes:...

 (selective for α₂-adrenergic receptors) psychoactive drug

Psychoactive drug

A psychoactive drug, psychopharmaceutical, or psychotropic is a chemical substance that crosses the blood–brain barrier and acts primarily upon the central nervous system where it affects brain function, resulting in changes in perception, mood, consciousness, cognition, and behavior...

 used as a sympatholytic

Sympatholytic

A sympatholytic drug is a medication which inhibits the postganglionic functioning of the sympathetic nervous system . They are indicated for various functions, for example they may be used as antihypertensives...

 or antihypertensive

Antihypertensive

The antihypertensives are a class of drugs that are used to treat hypertension . Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34%, of ischaemic heart disease by 21%, and reduce the likelihood of dementia, heart failure, and mortality from...

. 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

Hypertension

Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

 and gestational hypertension (also known as pregnancy-induced hypertension (PIH)).
Methyldopa is used in the clinical treatment of the following disorders:

• Hypertension
  Hypertension
  Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
  
   (or high blood pressure)
• Gestational hypertension (or pregnancy-induced hypertension) and pre-eclampsia
  Pre-eclampsia
  Pre-eclampsia or preeclampsia is a medical condition in which hypertension arises in pregnancy in association with significant amounts of protein in the urine....
  
  

Methyldopa has a dual

Functional Selectivity

Functional selectivity is the ligand-dependent selectivity for certain signal transduction pathways in one and the same receptor. This can be present when a receptor has several possible signal transduction pathways...

 mechanism of action

Mechanism of action

In pharmacology, the term mechanism of action refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect...

:

• It is a competitive inhibitor of the enzyme
  Enzyme
  Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
  
   DOPA decarboxylase, also known as aromatic L-amino acid decarboxylase
  Aromatic L-amino acid decarboxylase
  Aromatic L-amino acid decarboxylase is a lyase enzyme.-Reactions:It catalyzes several different decarboxylation reactions:* L-DOPA to dopamine - a neurotransmitter* 5-HTP to serotonin - also a neurotransmitter...
  
  , which converts L-DOPA into dopamine
  Dopamine
  Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
  
  .