Midodrine

Midodrine

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Systematic (IUPAC) name
(RS)- N-[2-(2,5-dimethoxyphenyl)-2-hydroxyethyl]glycinamide
Identifiers
CAS Number	133163-28-7
ATC code	C01CA17 (WHO)
PubChem	CID 4195
DrugBank	APRD01116
Synonyms	2-amino-N-[2-(2,5-dimethoxyphenyl)-2-hydroxy-ethyl]-acetamide
Chemical data
Formula	C12H18N2O4
Molar mass	254.282 g/mol[[]]
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Midodrine (brand names Amatine, ProAmatine, Gutron) is a vasopressor/antihypotensive agent. Midodrine was approved in the United States by the Food and Drug Administration (FDA) in 1996 for the treatment of orthostatic hypotension. In August 2010, the FDA proposed withdrawing this approval because the manufacturer, Shire plc, has failed to complete required studies after the medicine reached the market.

Chemical properties

Midodrineis an odorless, white, crystalline powder, soluble in water and sparingly soluble in methanol.

Mechanism of action

Midodrine is a prodrug which forms an active metabolite, desglymidodrine, which is an α₁-receptor agonist and exerts its actions via activation of the alpha-adrenergic receptors of the arteriolar and venous vasculature, producing an increase in vascular tone and elevation of blood pressure. Desglymidodrine does not stimulate cardiac beta-adrenergic receptors. Desglymidodrine diffuses poorly across the blood-brain barrier, and is therefore not associated with effects on the central nervous system.

File:Desglymidodrine.svg

Metabolite desglymidodrine

Metabolism

After oral administration, midodrine is rapidly absorbed. The plasma levels of the prodrug peak after about half an hour, and decline with a half-life of approximately 25 minutes, while the metabolite reaches peak blood concentrations about 1 to 2 hours after a dose of midodrine and has a half-life of about 3 to 4 hours. The absolute bioavailability of midodrine (measured as desglymidodrine) is 93%.

Indications

Midodrine hydrochloride tablets are indicated for the treatment of symptomatic orthostatic hypotension. In a critical care settings, it is widely used as an adjunctive therapy to weaning patients off of intravenous vasopressive medications. It has been suggested also as a treatment for chronic fatigue syndrome as well as for hepato-pulmonary syndrome.

Contraindications

Midodrine is contraindicated in patients with severe organic heart disease, acute renal disease, urinary retention, pheochromocytoma or thyrotoxicosis. Midodrine should not be used in patients with persistent and excessive supine hypertension.

Side effects

Headache; feeling of pressure/fullness in the head, vasodilation/flushing face, confusion/thinking abnormality, dry mouth; nervousness/anxiety and rash.

See also

• Lisdexamphetamine

External links

• Midodrine at drugs.com

de:Midodrin pl:Midodryna