[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Ergot alkaloids](https://durgical.com/en/pharmacology/classes/ergot-alkaloids/) › Methylergometrine

[Pharmacology](https://durgical.com/en/pharmacology/) · [Ergot alkaloids](https://durgical.com/en/pharmacology/classes/ergot-alkaloids/)

# Methylergometrine

Ergot derivative that causes a strong, sustained contraction of the uterus after the placenta is delivered. It raises blood pressure: never in pre-eclampsia.

Updated 2026-11-01

- Class: [Ergot alkaloids](https://durgical.com/en/pharmacology/classes/ergot-alkaloids/)
- Receptor: Serotonin 5-HT2 and alpha-adrenergic receptors of the myometrium
- ATC code: G02AB01

Also called: Methylergonovine

◎**Serotonin 5-HT2 and alpha-adrenergic receptors of the myometrium**Methylergometrine

ⓘ The crystal shows methylergometrine bound to the human serotonin 5-HT2B receptor. Its uterine effect involves related 5-HT2 and alpha-adrenergic receptors of the myometrium.

**Target in 3D:** Serotonin 5-HT2 and alpha-adrenergic receptors of the myometrium. PDB structure 6DRY (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/6DRY) · Drag to rotate · pinch to zoom

## Mechanism of action

Methylergometrine acts directly on uterine smooth muscle through serotonin and alpha-adrenergic receptors. It raises the tone, rate and strength of contractions and produces a sustained contraction that compresses the vessels and reduces blood loss. The same action on vascular smooth muscle causes vasoconstriction and high blood pressure.

- It stimulates 5-HT2 and alpha-adrenergic receptors of the myometrium
- Uterine tone rises and the contraction is sustained
- Placental bed vessels are compressed and bleeding falls
- On vessels: vasoconstriction and higher blood pressure

## Pharmacokinetics

**Absorption**
Given IM, IV (slowly) or by mouth; about 60% oral bioavailability

**Metabolism**
Liver, through CYP3A4

**Elimination**
Mainly by the liver, with some renal excretion

**Half-life**
About 3.4 hours after IM use, with wide variation

**Onset and duration**
Immediate IV, 2–5 minutes IM and 5–10 minutes by mouth

## Indications

- Uterine atony, haemorrhage and subinvolution after delivery of the placenta [Postpartum haemorrhage →](https://durgical.com/en/conditions/postpartum-haemorrhage/)

## Adverse effects

### Common

- High blood pressure, sometimes with headache
- Nausea, vomiting and abdominal pain
- Low blood pressure
- Chest pain and palpitations

### Serious (rare, important)

- Hypertensive crisis with seizures or stroke, especially after IV use
- Coronary vasospasm, angina and myocardial infarction
- Ventricular arrhythmias and AV block
- Severe ischaemia (ergotism) with strong CYP3A4 inhibitors
- In newborns given it by mistake: respiratory depression, seizures, cyanosis

## Contraindications

- Hypertension
- Pre-eclampsia and eclampsia
- Pregnancy (before birth)
- Hypersensitivity
- Use with strong or moderate CYP3A4 inhibitors

## Key interactions

**Strong CYP3A4 inhibitors (clarithromycin, erythromycin, HIV protease inhibitors, ketoconazole, itraconazole)**
Higher levels with severe vasospasm and ischaemia; do not combine

**CYP3A4 inducers (rifampicin, carbamazepine, phenytoin)**
Lower levels and a weaker effect

**Beta-blockers and other vasoconstrictors**
Greater vasoconstriction

**Nitroglycerin and other antianginal drugs**
Methylergometrine opposes their effect

## What is monitored

- Blood pressure before and after each dose
- Uterine tone and blood loss
- Chest pain, headache and vision changes
- Colour, temperature and pulses of hands and feet (vasospasm)

## Administration and safety

- Check blood pressure before giving it; it is not used if the patient is hypertensive or has pre-eclampsia.
- IV use is not routine; when essential, it is injected slowly while blood pressure is watched. Avoid intra-arterial injection.
- Store refrigerated and protected from light; use only if the solution is clear and colourless.
- Store apart from newborn medicines: it has been given to newborns by mistake.

## Nursing care

- Before the dose: blood pressure and a history of hypertension, pre-eclampsia or heart disease.
- After the dose: recheck blood pressure, uterine tone and lochia.
- Ask about chest pain, severe headache, numb or cold fingers.
- Review the medicine list for macrolides, protease inhibitors or azole antifungals.
- Teaching: breastfeeding is paused during treatment and for a short time after the last dose, as the label states.

## Pregnancy and breastfeeding

Contraindicated before birth because it contracts the uterus; it is used only after delivery of the placenta (or of the anterior shoulder).

## Memory aid

«Methyl-ERGO-metrine raises the pressure, so CHECK the pressure»: no ergots in high blood pressure, pre-eclampsia or with macrolides.

## Test yourself

Think of the answer, then tap the question to see it.

## What must be checked before giving methylergometrine?

Blood pressure: it is contraindicated in hypertension and pre-eclampsia because it causes vasoconstriction.

## Why is methylergometrine dangerous with clarithromycin?

Clarithromycin inhibits CYP3A4; methylergometrine levels rise and cause severe vasospasm and ischaemia.

## Why should methylergometrine not be given IV routinely?

A fast IV dose can cause sudden hypertension and stroke; when IV use is essential it is given slowly with blood pressure checks.

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## Related drugs

- [Ergometrine](https://durgical.com/en/pharmacology/ergometrine/)
- [Oxytocin](https://durgical.com/en/pharmacology/oxytocin/)
- [Carboprost](https://durgical.com/en/pharmacology/carboprost/)
- [Misoprostol](https://durgical.com/en/pharmacology/misoprostol/)

## Related conditions

- [Postpartum haemorrhage](https://durgical.com/en/conditions/postpartum-haemorrhage/)

[← Back to the class: Ergot alkaloids](https://durgical.com/en/pharmacology/classes/ergot-alkaloids/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - METHYLERGONOVINE MALEATE injection, solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a9a3079e-b62b-4858-920e-d8f5cb38481e) (DailyMed (U.S. National Library of Medicine), 2026); [WHO recommendations: uterotonics for the prevention of postpartum haemorrhage](https://www.who.int/publications/i/item/9789241550420) (World Health Organization, 2018); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=G02AB) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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