Methergin (Methylergometrine)
Ergot alkaloid uterotonic for prevention and treatment of postpartum haemorrhage
Methergin (methylergometrine) is a potent uterotonic medication belonging to the ergot alkaloid class. It is primarily used in obstetric settings to prevent and treat postpartum haemorrhage by producing strong, sustained contractions of the uterine muscle. Administered as an intramuscular or intravenous injection by healthcare professionals, Methergin plays a critical role in managing excessive bleeding after childbirth, caesarean section, or pregnancy loss. This guide provides comprehensive, evidence-based information on its uses, dosage, side effects, and drug interactions.
Quick Facts
Key Takeaways
- Methergin (methylergometrine) is used to prevent and treat postpartum haemorrhage after delivery, caesarean section, or pregnancy loss by causing strong uterine contractions.
- It is administered by healthcare professionals as an intramuscular or intravenous injection; it is not a medication you take at home on your own.
- Methergin is strictly contraindicated during pregnancy and must not be given before delivery of the baby's anterior shoulder due to risk of harm to both mother and foetus.
- Patients with hypertension, pre-eclampsia, vascular disease, or sepsis must not receive this medication. Careful monitoring is required for those with mild to moderate high blood pressure or heart disease.
- Breastfeeding should be avoided during treatment and for at least 12 hours after the last dose, as methylergometrine passes into breast milk.
What Is Methergin and What Is It Used For?
Methergin contains the active substance methylergometrine maleate, a semi-synthetic ergot alkaloid that exerts a potent and sustained contractile effect on the smooth muscle of the uterus (myometrium). Unlike oxytocin, which produces rhythmic contractions, methylergometrine causes a sustained tonic contraction that is particularly effective at compressing the blood vessels at the placental implantation site, thereby reducing blood loss.
Postpartum haemorrhage (PPH) remains one of the leading causes of maternal morbidity and mortality worldwide. According to the World Health Organization (WHO), approximately 14 million women experience PPH each year, and it accounts for nearly 25% of all maternal deaths globally. Methergin is one of the essential medicines included in the WHO Model List of Essential Medicines for the management of this life-threatening condition.
The primary clinical indications for Methergin include:
- Active management of the third stage of labour: Administration after delivery of the placenta to reduce blood loss and prevent postpartum haemorrhage.
- Treatment of postpartum haemorrhage: Used when the uterus fails to contract adequately (uterine atony) following vaginal delivery or caesarean section.
- Uterine subinvolution: Treatment when the uterus does not return to its normal pre-pregnancy size in the days and weeks following delivery.
- Post-abortion or post-miscarriage bleeding: Management of excessive bleeding following spontaneous or therapeutic pregnancy termination.
Methylergometrine has been used in obstetric practice since the 1930s and remains a cornerstone of PPH management alongside oxytocin and misoprostol. The International Federation of Gynecology and Obstetrics (FIGO) and the Royal College of Obstetricians and Gynaecologists (RCOG) include methylergometrine in their treatment algorithms for postpartum haemorrhage, typically as a second-line agent after oxytocin.
It is important to understand that Methergin is a hospital-based medication administered exclusively by trained healthcare professionals. It is not available for self-administration or home use. The injection is supplied as a clear, colourless solution in 1 ml ampoules, each containing 0.2 mg of methylergometrine maleate.
What Should You Know Before Receiving Methergin?
Contraindications
There are several situations in which Methergin must absolutely not be used. Healthcare providers will carefully assess each patient before administration. Methergin is contraindicated in the following circumstances:
- You are pregnant — methylergometrine poses a risk of foetal harm due to its powerful uterine contractile effects.
- During the first or second stage of labour — it must not be administered before delivery of the baby's anterior shoulder.
- You have severe hypertension (very high blood pressure) — methylergometrine can further elevate blood pressure to dangerous levels.
- You have pre-eclampsia or eclampsia — conditions characterised by high blood pressure, oedema, proteinuria, and/or seizures during pregnancy.
- You have vascular occlusive disease — including blood clots (thrombosis) or peripheral vascular disease, as methylergometrine causes vasoconstriction.
- You have sepsis (blood poisoning) — due to the risk of exacerbating cardiovascular instability.
- You are allergic to methylergometrine maleate, any other ergot alkaloid, or any of the inactive ingredients.
Warnings and Precautions
Even when Methergin is not absolutely contraindicated, there are clinical situations where extra caution is warranted. Your healthcare team will carefully weigh the benefits and risks before administering this medication in the following circumstances:
- Mild to moderate hypertension: Blood pressure must be closely monitored during and after administration, as methylergometrine can cause further increases in blood pressure through its vasoconstrictive effects.
- Cardiovascular disease or risk factors: Patients with existing heart disease, or those with risk factors such as smoking, obesity, diabetes, or high cholesterol, may be at increased risk of coronary artery spasm or other cardiovascular events.
- Hepatic impairment: Methylergometrine is metabolised primarily by the liver via the CYP3A4 enzyme system. Reduced liver function may lead to higher drug levels and an increased risk of adverse effects.
- Renal impairment: Patients with kidney disease may experience altered drug clearance. Dose adjustments may be necessary.
Healthcare professionals administering Methergin should have resuscitation equipment readily available and should monitor the patient's blood pressure, heart rate, and uterine response throughout treatment. Intravenous administration should be reserved for emergency situations and given slowly over at least 60 seconds, as rapid IV injection can cause a sudden and dangerous spike in blood pressure.
Pregnancy and Breastfeeding
Methylergometrine is classified as a known teratogen and must not be used during pregnancy. Its powerful oxytocic effect can induce premature labour, placental abruption, and severe complications for both mother and foetus. The only appropriate use is after delivery, once the baby has been born.
Regarding breastfeeding, methylergometrine is excreted into breast milk and may affect the nursing infant. Reported effects in breastfed infants include irritability and gastrointestinal symptoms. Current guidelines recommend:
- Avoid breastfeeding during active treatment with Methergin.
- Wait at least 12 hours after the last dose before resuming breastfeeding.
- Discard any breast milk expressed during the treatment period and the 12-hour waiting period.
- Consult with your healthcare provider for individual guidance based on your clinical situation.
Methergin may cause dizziness and, rarely, seizures. Patients should exercise caution when driving or operating machinery after receiving this medication. You are responsible for assessing whether you are fit to perform these activities. Discuss any concerns with your healthcare provider.
This medicine contains less than 1 mmol sodium (23 mg) per dose, meaning it is essentially sodium-free. This is relevant for patients on a sodium-restricted diet.
How Does Methergin Interact with Other Drugs?
Drug interactions with methylergometrine are primarily mediated through two mechanisms: pharmacokinetic interactions involving the CYP3A4 hepatic enzyme system, and pharmacodynamic interactions where the combined effects of multiple drugs produce harmful outcomes. The following table summarises the most clinically important interactions:
Major Interactions
| Drug / Drug Class | Examples | Mechanism & Risk |
|---|---|---|
| Azole antifungals | Ketoconazole, itraconazole, voriconazole | Strong CYP3A4 inhibitors. Increase plasma levels of methylergometrine, raising the risk of severe vasoconstriction and ergotism. |
| Macrolide antibiotics | Erythromycin, clarithromycin, troleandomycin | CYP3A4 inhibitors that significantly increase methylergometrine levels, potentially causing vasospasm and ischaemia. |
| HIV protease inhibitors | Ritonavir, nelfinavir, indinavir, delavirdine | Potent CYP3A4 inhibitors. Concurrent use can lead to dangerous ergot toxicity with peripheral and cerebral vasospasm. |
| Vasoconstrictive migraine drugs | Sumatriptan, ergotamine, beta-blockers | Additive vasoconstrictive effects. Risk of severe hypertension, coronary artery spasm, and peripheral ischaemia. |
| Bromocriptine | Bromocriptine (lactation suppression) | Concurrent use not recommended. Both are ergot derivatives; combination increases risk of hypertension and vasospasm. |
Moderate Interactions
| Drug / Drug Class | Examples | Mechanism & Risk |
|---|---|---|
| Prostaglandins | Sulprostone, dinoprostone, misoprostol | Methergin enhances the uterotonic effect of prostaglandins. May lead to excessive uterine contraction and potential uterine rupture. |
| Anti-angina drugs | Glyceryl trinitrate, isosorbide dinitrate | Methergin reduces the vasodilatory effect of nitrates, potentially diminishing their anti-anginal efficacy. |
| CYP3A4 inducers | Nevirapine, rifampicin | May decrease plasma levels of methylergometrine, potentially reducing its therapeutic effectiveness. |
Always inform your healthcare team about all medications you are currently taking, have recently taken, or might take. This includes prescription medicines, over-the-counter drugs, herbal supplements, and vitamins. Your medical team will review potential interactions before administering Methergin and will choose the safest treatment approach for your individual situation.
What Is the Correct Dosage of Methergin?
Methergin is exclusively administered by qualified healthcare professionals in hospital or clinical settings. The dosage is individualised based on the clinical situation, the patient's medical history, and the response to treatment. Patients do not self-administer this medication.
Standard Dosing
Intramuscular Injection (Preferred Route)
Dose: 0.2 mg (1 ml of 0.2 mg/ml solution)
Onset: 2–5 minutes
Duration: Approximately 3 hours
The intramuscular route is preferred for routine prophylactic and therapeutic use. The injection is typically given into the deltoid muscle or the lateral thigh. This route provides a more gradual onset of action with a lower risk of sudden blood pressure elevation compared to intravenous administration.
Intravenous Injection (Emergency Use Only)
Dose: 0.2 mg (1 ml of 0.2 mg/ml solution), administered slowly over at least 60 seconds
Onset: Within 1 minute (almost immediate)
Duration: Approximately 45 minutes
Intravenous administration is reserved for life-threatening postpartum haemorrhage where rapid uterine contraction is essential. The injection must be given slowly to minimise the risk of acute hypertension, cerebrovascular events, and cardiac complications. Blood pressure should be monitored continuously during IV administration.
- Rapid intravenous injection can cause a sudden, dangerous spike in blood pressure, potentially leading to cerebrovascular haemorrhage, seizures, or myocardial infarction.
- Repeated doses may be given at intervals as determined by the treating physician, but total daily dose and frequency must be carefully monitored.
- The duration of treatment should be kept as short as possible to minimise the risk of adverse effects.
Special Populations
Hepatic impairment: Patients with liver disease may metabolise methylergometrine more slowly, as it undergoes hepatic metabolism via CYP3A4. Dose reduction or avoidance may be necessary, and close monitoring is essential.
Renal impairment: While renal excretion is not the primary elimination pathway, patients with significant kidney disease may require dose adjustments and enhanced monitoring.
Elderly patients: Older patients may be more susceptible to the vasoconstrictive effects of methylergometrine, particularly if they have underlying cardiovascular disease. Extra caution is warranted.
Overdose
Overdose with methylergometrine can produce serious symptoms including severe nausea and vomiting, abdominal pain, numbness and tingling in the extremities, elevated blood pressure, respiratory depression, convulsions, and in severe cases, peripheral vasoconstriction leading to gangrene. In the event of a suspected overdose:
- Contact emergency medical services immediately.
- Treatment is supportive and symptomatic, managed in a hospital intensive care setting.
- Vasodilators may be used to counteract severe vasoconstriction.
- Anticonvulsants may be administered for seizure management.
- Continuous monitoring of vital signs, particularly blood pressure and cardiac function, is essential.
What Are the Side Effects of Methergin?
Like all medicines, Methergin can cause side effects, although not everyone experiences them. Side effects are classified by frequency based on clinical trial data and post-marketing surveillance reports. The following frequency grid presents the known adverse reactions associated with methylergometrine:
Common
Affects more than 1 in 100 patients
- Elevated blood pressure (hypertension)
- Headache
- Skin rash
- Abdominal pain (caused by uterine contractions)
Uncommon
Affects 1 in 100 to 1 in 1,000 patients
- Low blood pressure (hypotension)
- Chest pain
- Dizziness
- Excessive sweating
- Seizures (convulsions)
- Nausea
- Vomiting
Rare
Affects fewer than 1 in 1,000 patients
- Slow heart rate (bradycardia) or rapid heart rate (tachycardia)
- Palpitations (awareness of heartbeat)
- Vasoconstriction of small blood vessels (peripheral vasospasm)
Very Rare
Affects fewer than 1 in 10,000 patients
- Severe hypersensitivity reactions (anaphylaxis) — including itching, skin reactions, swelling, and difficulty breathing
- Hallucinations
- Tinnitus (ringing in the ears)
- Myocardial infarction (heart attack)
- Coronary artery vasospasm
- Inflammation of blood vessels (vasculitis)
- Nasal congestion
- Diarrhoea
- Muscle cramps
Frequency Not Known
Cannot be estimated from available data
- Weakness or paralysis in legs and face, speech difficulties (signs of cerebrovascular events)
- Angina pectoris — chest pain from reduced blood flow to the heart
- Severely irregular heart rhythm (symptoms of AV block)
Most side effects of Methergin are transient and resolve as the medication is cleared from the body. The vasoconstrictive properties of methylergometrine are responsible for many of the cardiovascular side effects, which is why the drug is contraindicated in patients with pre-existing hypertension, vascular disease, and heart conditions.
If you experience any unusual symptoms after receiving Methergin, inform your healthcare team immediately. Serious cardiovascular events, although very rare, require prompt medical intervention. Healthcare professionals monitoring patients who have received Methergin should be vigilant for signs of peripheral ischaemia (cold, pale, or numb extremities), severe hypertension, chest pain, or neurological changes.
Reporting suspected adverse reactions after a medicine has been authorised is important. It allows continuous monitoring of the benefit-risk balance of the medicine. Healthcare professionals and patients are encouraged to report any suspected adverse reactions through their national pharmacovigilance reporting system.
How Should Methergin Be Stored?
Proper storage of Methergin is essential to maintain its potency and safety. As a hospital-based injectable medication, storage is primarily the responsibility of pharmacy and nursing staff. The following storage conditions must be observed:
- Temperature: Store in a refrigerator at 2°C to 8°C (36°F to 46°F).
- Do not freeze: Freezing can damage the molecular structure of methylergometrine and compromise its efficacy.
- Light protection: The solution is light-sensitive. Store ampoules in the original carton to protect from light exposure.
- Room temperature storage: If necessary, Methergin can be kept at temperatures up to 25°C (77°F) for a maximum period of 2 weeks. After this period, unused ampoules must be discarded.
- Expiry date: Do not use after the expiration date printed on the carton. The expiry date refers to the last day of that month.
- Keep out of reach: Store out of the sight and reach of children.
Before use, healthcare professionals should visually inspect the solution. Methergin should appear as a clear, colourless solution. Do not use if the solution appears discoloured, cloudy, or contains particulate matter. Each carton contains 10 ampoules of 1 ml each.
What Does Methergin Contain?
Understanding the complete composition of any medication is important for identifying potential allergens and for pharmaceutical compatibility considerations. Methergin 0.2 mg/ml solution for injection contains the following components:
Active Substance
Methylergometrine maleate (also known as methylergonovine maleate) — 0.2 mg per 1 ml ampoule. Methylergometrine is a semi-synthetic derivative of the natural ergot alkaloid ergonovine (ergometrine). It belongs to the lysergic acid family and exerts its pharmacological effects primarily through agonism at serotonin (5-HT) and alpha-adrenergic receptors in the uterine smooth muscle.
Inactive Ingredients (Excipients)
- Maleic acid: Used as a buffer to maintain the pH of the solution within the optimal range for stability and tolerability.
- Sodium chloride: Provides isotonicity, ensuring the injection solution has the same osmotic pressure as body fluids, which reduces pain and tissue damage at the injection site.
- Water for injections: The purified solvent base meeting pharmacopoeia standards for parenteral preparations.
The solution is presented in clear glass ampoules containing 1 ml of clear, colourless liquid. Each carton contains 10 ampoules. The marketing authorisation holder and manufacturer is Essential Pharma Limited, based in Birkirkara, Malta.
Frequently Asked Questions About Methergin
Both Methergin (methylergometrine) and oxytocin are uterotonic agents used to prevent and treat postpartum haemorrhage, but they differ in important ways. Oxytocin produces rhythmic, pulsatile contractions similar to natural labour and is generally considered the first-line agent for PPH prevention. Methergin produces sustained, tonic contractions of the entire uterus and is typically used as a second-line agent or in combination with oxytocin. Methergin has more contraindications (particularly in hypertensive patients) and a different side effect profile. The choice between them depends on the clinical situation and patient factors.
The onset of action depends on the route of administration. When given intramuscularly (the preferred route), Methergin begins producing uterine contractions within 2 to 5 minutes. When given intravenously (reserved for emergencies), the effect is almost immediate, typically within 1 minute. The duration of effect is approximately 3 hours after intramuscular injection and about 45 minutes after intravenous administration.
Methergin is strictly contraindicated in patients with severe hypertension and in those with pre-eclampsia or eclampsia. In women with mild to moderate high blood pressure, it may be used with extreme caution under close blood pressure monitoring. However, in most cases, alternative uterotonic agents such as oxytocin or misoprostol are preferred for hypertensive patients, as these medications carry a lower risk of causing dangerous blood pressure elevation. Your healthcare team will assess your individual risk profile and choose the safest option.
Although very rare, Methergin can cause serious cardiovascular effects including myocardial infarction (heart attack), coronary artery vasospasm, and severe cardiac arrhythmias. These risks are highest in patients with pre-existing cardiovascular disease or risk factors such as smoking, obesity, diabetes, and high cholesterol. Rapid intravenous injection significantly increases the risk of acute cardiovascular events, which is why IV administration must be performed slowly over at least 60 seconds. Healthcare teams carefully assess cardiac risk before administering Methergin.
You should wait at least 12 hours after the last dose of Methergin before resuming breastfeeding. Methylergometrine passes into breast milk and could potentially affect the nursing infant. Any breast milk expressed during treatment and the 12-hour waiting period should be discarded. After this waiting period, it is safe to resume breastfeeding. If you are concerned about maintaining your milk supply during this period, you can continue to express milk (pumping and discarding) to maintain production.
All information is based on the approved Summary of Product Characteristics (SmPC), international medical guidelines, and peer-reviewed research: WHO Recommendations for the Prevention and Treatment of Postpartum Haemorrhage (2023 update), FIGO Guidelines on Prevention of Postpartum Haemorrhage, RCOG Green-top Guideline No. 52 on Postpartum Haemorrhage, the European Medicines Agency (EMA) assessment reports, and the Cochrane Database of Systematic Reviews. All medical claims follow the GRADE evidence framework.
References
- World Health Organization. WHO Recommendations for the Prevention and Treatment of Postpartum Haemorrhage. Geneva: WHO; 2023 (updated). Available at: www.who.int/publications.
- International Federation of Gynecology and Obstetrics (FIGO). FIGO Guidelines: Prevention and Treatment of Postpartum Haemorrhage in Low-Resource Settings. Int J Gynaecol Obstet. 2022;159(Suppl 1):S1-S48.
- Royal College of Obstetricians and Gynaecologists (RCOG). Green-top Guideline No. 52: Prevention and Management of Postpartum Haemorrhage. London: RCOG; 2023.
- American College of Obstetricians and Gynecologists (ACOG). Practice Bulletin No. 183: Postpartum Hemorrhage. Obstet Gynecol. 2017;130(4):e168-e186.
- Gallos ID, Papadopoulou A, Man R, et al. Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis. Cochrane Database Syst Rev. 2018;12(12):CD011689.
- European Medicines Agency (EMA). Methylergometrine — Summary of Product Characteristics. Available at: www.ema.europa.eu.
- Essential Pharma Limited. Methergin 0.2 mg/ml Solution for Injection — Summary of Product Characteristics (SmPC). Last updated: October 2023.
- British National Formulary (BNF). Ergometrine with oxytocin. National Institute for Health and Care Excellence (NICE). Available at: bnf.nice.org.uk.
Editorial Team
iMedic Medical Editorial Team — Specialists in Obstetrics, Gynaecology and Clinical Pharmacology. All content is based on current evidence-based guidelines and peer-reviewed research.
Reviewed by the iMedic Medical Review Board — an independent panel of senior physicians who verify medical accuracy, completeness, and adherence to international clinical guidelines (WHO, FIGO, RCOG, ACOG).
This article follows the iMedic editorial process: initial drafting by medical specialists, peer review by the Medical Review Board, fact-checking against primary sources, and regular updates to reflect the latest evidence. All content adheres to GRADE evidence framework standards. No commercial funding or pharmaceutical industry influence. Last reviewed: .