Methylergometrine

Methylergometrine

Systematic (IUPAC) name
9,10-Didehydro-N-[1-(hydroxymethyl)-propyl]-D-lysergamide
Clinical data
Trade names	Methergine
AHFS/Drugs.com	International Drug Names
MedlinePlus	a601077
Pregnancy category	Contraindicated
Legal status	℞ (Prescription only)
Routes of administration	Oral
Pharmacokinetic data
Metabolism	Liver
Biological half-life	30–120 min
Excretion	Mostly bile
Identifiers
CAS Number	113-42-8 Y
ATC code	G02AB01 (WHO)
PubChem	CID: 8226
IUPHAR/BPS	150
ChemSpider	7933 N
UNII	W53L6FE61V N
ChEMBL	CHEMBL1201356 N
Synonyms	Methylergobasine Methylergobrevin Methylergonovine
Chemical data
Formula	C20H25N3O2
Molecular mass	339.432 g/mol
SMILES CC[C@@H](CO)NC(=O)[C@@H]2/C=C1/c3cccc4N\C=C(\C[C@H]1N(C)C2)c34
InChI InChI=1S/C20H25N3O2/c1-3-14(11-24)22-20(25)13-7-16-15-5-4-6-17-19(15)12(9-21-17)8-18(16)23(2)10-13/h4-7,9,13-14,18,21,24H,3,8,10-11H2,1-2H3,(H,22,25)/t13-,14+,18-/m1/s1 N Key:UNBRKDKAWYKMIV-QWQRMKEZSA-N N
Physical data
Melting point	172 °C (342 °F)
Solubility in water	insoluble mg/mL (20 °C)
NY (what is this?)  (verify)

Methylergometrine (other names include methylergonovine, methylergobasin, methergine, and D-lysergic acid 1-butanolamide) is a synthetic analogue of ergonovine, a psychedelic alkaloid found in ergot, and many species of morning glory. It is a member of the ergoline family and chemically similar to LSD, ergine, ergometrine, and lysergic acid. Due to its oxytocic properties, it has a medical use in obstetrics. According to Jonathan Ott, methylergonovine has LSD-like actions above 2 milligrams. Clinical dosages are ten times lower.

Methylergometrine maleate is marketed under the trade name Methergine.

Uses

Obstetric use

Methylergometrine is a smooth muscle constrictor that mostly acts on the uterus. It is most commonly used to prevent or control excessive bleeding following childbirth and spontaneous or elective abortion, and also to aid in expulsion of retained products of conception after a missed abortion (miscarriage in which all or part of the fetus remains in the uterus) and to help deliver the placenta after childbirth. It is available as tablets or injection (IM or IV) or in liquid form to be taken orally.

Migraine

Methylergometrine is sometimes used for both prevention and acute treatment of migraine. It is an active metabolite of methysergide.

Contraindications

Methylergometrine is contraindicated in patients with hypertension and preeclampsia. It is also contraindicated in HIV positive patients taking Protease inhibitors, Delavirdine and Efavirenz.

Side effects

Adverse effects include:

• Cholinergic effects such as nausea, vomiting, and diarrhea
• Dizziness
• Pulmonary hypertension
• Coronary artery vasoconstriction
• Severe systemic hypertension (especially in patients with preeclampsia)
• Convulsions

In excessive doses, methylergometrine can also lead to cramping, respiratory depression and coma.

Interactions

Methylergometrine likely interacts with drugs that inhibit the liver enzyme CYP3A4, such as azole antifungals, macrolide antibiotics and many HIV drugs. It can also increase constriction of blood vessels caused by sympathomimetic drugs and other ergot alkaloids.

Mechanism of action

Methylergometrine is a partial agonist/antagonist on serotonergic, dopaminergic and alpha-adrenergic receptors. Its specific binding and activation pattern on these receptors leads to a highly, if not completely, specific contraction of smooth uterus muscle via 5-HT_2A serotonin receptors, while blood vessels are affected to a lesser extent compared to other ergot alkaloids.

See Also

Ergometrine