What is Ergometrine? Understanding the Obstetric Medication

October 5, 2025 •

4 min read

For centuries, compounds derived from the ergot fungus were used to induce uterine contractions in childbirth, a practice that eventually led to the development of modern medicines like ergometrine. Also known as ergonovine, this prescription medication is a potent uterotonic agent primarily used to control and prevent heavy bleeding after childbirth, a condition known as postpartum hemorrhage.

Quick Summary

Ergometrine is a powerful ergot alkaloid medication that induces sustained uterine contractions. It is a key tool in obstetrics for preventing and managing postpartum bleeding caused by uterine atony.

Key Points

Ergometrine is a potent uterotonic medication: It is primarily used in obstetrics to cause the uterus to contract forcefully and is derived from ergot fungi.
Its main use is to prevent and treat postpartum hemorrhage (PPH): Ergometrine helps stop heavy bleeding after childbirth by constricting blood vessels in the uterus.
It operates through a complex receptor mechanism: The drug affects alpha-adrenergic, dopaminergic, and serotonergic receptors, causing both uterine contractions and systemic vasoconstriction.
Cardiovascular risks are a major concern: Side effects include increased blood pressure, nausea, and, in rare cases, severe complications like myocardial ischemia and gangrene, especially with high doses or rapid IV injection.
It has significant contraindications: Ergometrine is not suitable for patients with hypertension, pre-eclampsia, heart disease, or during labor induction due to the risk of uterine tetany.
Ergometrine's action differs from oxytocin: Unlike oxytocin's rhythmic contractions, ergometrine produces sustained, tonic contractions and has a higher risk of adverse effects like nausea and hypertension.

What is Ergometrine? An Overview

Ergometrine, also called ergonovine, is a semi-synthetic ergot alkaloid derived from the Claviceps fungi. It acts as a uterotonic, meaning it causes the uterus to contract. This makes it valuable in obstetric care for managing the third stage of labor and treating postpartum hemorrhage (PPH), a serious complication involving excessive bleeding after childbirth due to the uterus not contracting properly.

Ergometrine induces sustained, forceful uterine contractions, which constrict blood vessels in the uterine wall to stop bleeding. While it can be taken orally, it's typically given via intramuscular (IM) or slow intravenous (IV) injection for quicker action in emergencies.

Mechanism of Action: How Ergometrine Works

Ergometrine affects multiple receptors, including alpha-adrenergic, dopaminergic, and serotonergic (5-HT2) receptors.

It directly stimulates uterine smooth muscle. Lower doses increase contraction frequency and amplitude with relaxation periods, but higher doses used for PPH cause sustained, forceful contractions without relaxation. This prolonged uterine tone helps constrict bleeding vessels. Ergometrine also constricts peripheral and coronary blood vessels, which can raise blood pressure and is relevant to its safety and contraindications.

Primary Medical Uses of Ergometrine

Ergometrine's main uses stem from its potent uterotonic properties:

Prevention of Postpartum Hemorrhage: It's often given IM with oxytocin (as Syntometrine) during the third stage of labor to reduce PPH risk.
Treatment of Postpartum Hemorrhage: IV administration can induce strong contractions to stop bleeding from uterine atony after childbirth.
Treatment of Post-abortion Bleeding: It is used to manage bleeding after abortion by inducing contractions to expel remaining tissue and control hemorrhage.

Ergometrine vs. Oxytocin: A Comparison

Both ergometrine and oxytocin are uterotonics used in obstetrics, but they differ in how they affect the uterus and their typical uses.


Feature	Ergometrine	Oxytocin
Mechanism	Stimulates uterine and vascular smooth muscle via multiple receptors (alpha-adrenergic, dopaminergic, serotonergic).	Acts on specific oxytocin receptors in the uterus.
Contraction Pattern	Produces sustained, forceful (tetanic) contractions.	Induces rhythmic contractions with relaxation in between.
Onset of Action (IM)	2–5 minutes.	3–7 minutes.
Duration of Action (IM)	30–120 minutes.	Up to 1 hour.
Primary Use	Prophylaxis and treatment of postpartum hemorrhage (especially in combination with oxytocin).	Induction or augmentation of labor, and prophylaxis of PPH.
Side Effects	Higher rates of nausea, vomiting, and potential for hypertension.	Fewer side effects, though rapid IV injection can cause a transient drop in blood pressure.

Important Side Effects and Risks

Ergometrine has various side effects, which can be mild or severe, particularly in patients with conditions like hypertension.

Common side effects include:

Nausea and vomiting
Headache
Increased blood pressure
Abdominal pain and leg cramps
Dizziness

Serious but rare side effects include:

Ergotism: Severe, prolonged vasoconstriction can lead to peripheral ischemia, gangrene, and hallucinations.
Myocardial Ischemia and Infarction: Vasoconstriction can affect coronary arteries, potentially causing a heart attack, especially in high-risk patients.
Hypertensive Crisis: Rapid IV administration can cause sudden, severe spikes in blood pressure.
Allergic Reactions: Rare hypersensitivity can cause symptoms like shortness of breath or chest pain.

Contraindications: When Ergometrine is Not Used

Ergometrine is avoided in several situations due to the risk of harmful effects:

Pregnancy and Labor Induction: Not used to induce labor because of the risk of uterine tetany, fetal distress, and uterine rupture.
Cardiovascular Conditions: Dangerous for patients with hypertension, pre-eclampsia, eclampsia, or heart disease due to its vasoconstrictive effects.
Peripheral Vascular Disease: Increases the risk of ischemia in patients with this condition.
Sepsis: Contraindicated in cases of severe sepsis.
Hypersensitivity: Should not be given to patients with an allergy to ergometrine or other ergot alkaloids.

Dosage and Administration

Dosage and administration depend on the clinical need and patient factors, and should be determined by a healthcare professional. For PPH prevention, it's often given IM with oxytocin after the infant's anterior shoulder is delivered. For existing PPH, a dose may be given intravenously (slowly over at least one minute) for faster action. Oral administration may be considered for continued management for a limited duration. Careful monitoring of blood pressure and uterine response is crucial during administration.

Conclusion: Balancing Efficacy and Risk

Ergometrine is a crucial medication in obstetric care, particularly for managing postpartum hemorrhage. As an ergot alkaloid, it causes powerful uterine contractions and systemic vasoconstriction. While effective in controlling bleeding, its use requires careful consideration of side effects, especially hypertension and cardiovascular risks. Contraindications include cardiovascular and hypertensive conditions. Compared to oxytocin, it provides more prolonged and forceful contractions, making it a valuable option, often in combination therapy. Its use highlights the need to balance effective treatment with risk management for positive maternal outcomes.

For more detailed information on ergometrine in the context of PPH management, refer to research findings such as this article on postpartum hemorrhage.

Frequently Asked Questions

Ergometrine causes sustained, forceful (tetanic) contractions of the uterus, while oxytocin produces more rhythmic contractions. Ergometrine has a higher risk of side effects like nausea and high blood pressure, and is often used in combination with oxytocin (as Syntometrine) or as a second-line treatment for PPH.

Common side effects include nausea, vomiting, headache, increased blood pressure, and abdominal pain. Less frequent side effects can include dizziness, leg cramps, or ringing in the ears.

Ergometrine is contraindicated in hypertensive patients because it has a systemic vasoconstrictive effect, meaning it narrows blood vessels throughout the body. In a patient who already has high blood pressure, this can lead to a dangerous hypertensive crisis or increase the risk of serious cardiovascular events like a heart attack.

A single dose of ergometrine to control postpartum bleeding is not typically a barrier to breastfeeding. However, ergometrine is secreted into breast milk, and multiple or high doses could suppress lactation and potentially cause chronic ergot poisoning in the infant, so it is generally avoided with prolonged use.

No, ergometrine is a uterotonic and is not indicated for pain relief. Its purpose is to induce uterine contractions to manage bleeding, not to alleviate pain.

Methylergometrine (often sold under the brand name Methergine) is a close chemical relative and derivative of ergometrine (ergonovine). Both are potent uterotonics from the ergot alkaloid family with similar uses in obstetrics, though they may have slightly different side effect profiles and potencies.

Ergometrine can be administered orally or via intramuscular (IM) or slow intravenous (IV) injection, under the guidance of a healthcare professional. IV injection is often used for rapid effect in emergencies, with potential follow-up oral administration for a limited time.