Ergometrine

Intramuscular
Postabortal haemorrhage, Prophylaxis of postabortal haemorrhage

Intramuscular
Active management of the third stage of labour

Parenteral
Postpartum haemorrhage, Prophylaxis of postpartum haemorrhage

Severe: Contraindicated.

Severe: Contraindicated.

Incompatible with epinephrine hydrochloride, amobarbital Na, ampicillin Na, cefalotin Na, chloramphenicol Na succinate, chlortetracycline hydrochloride, heparin Na, metaraminol tartrate, methicillin Na, nitrofurantoin Na, novobiocin Na, pentobarbital Na, sulfadiazine Na, sulfafurazole, diethanolamine, thiopental Na, vitamin B complex with C, warfarin Na.

Primary or secondary uterine inertia, eclampsia or pre-eclampsia, severe hypertension, severe cardiac disorders, occlusive vascular disease (e.g. Raynaud’s disease or phenomenon), sepsis, threatened spontaneous abortion, any suspicion of retained placenta. Severe hepatic or renal impairment. Pregnancy (including induction of labour, 1st and 2nd stages of labour prior to the delivery of the anterior shoulder) and lactation (if >1 dose is administered). Concomitant use with strong CYP3A4 inhibitors (e.g. macrolide antibiotics, HIV protease or reverse transcriptase inhibitors, azole antifungals).

Patient with hypocalcaemia, mild to moderate forms of hypertension or cardiac disease, coronary artery disease, venoatrial shunts, mitral valve stenosis. Patients under general anaesthesia. In abnormal foetal presentations (e.g. breech), do not administer before delivery of the child is completed, and in multiple births not before the last child has been delivered. Mild to moderate hepatic or renal impairment.

Significant: Vasoconstriction, hypertension, decreased heart rate, exacerbation of porphyria, decreased prolactin serum levels. Rarely, acute pulmonary oedema.
Cardiac disorders: Cardiac arrhythmias, bradycardia, chest pain, palpitations, coronary arteriospasm.
Ear and labyrinth disorders: Tinnitus.
Gastrointestinal disorders: Abdominal pain, nausea, vomiting, diarrhoea, oesophageal spasm, unpleasant taste.
Immune system disorders: Anaphylactic or anaphylactoid reactions.
Metabolism and nutrition disorders: Water intoxication.
Nervous system disorders: Dizziness, headache, vertigo.
Psychiatric disorders: Hallucinations.
Renal and urinary disorders: Haematuria.
Respiratory, thoracic and mediastinal disorders: Dyspnoea, pulmonary oedema, nasal congestion, pleural thickening.
Skin and subcutaneous tissue disorders: Rash, angioedema, gangrene, sweating.
Vascular disorders: Hypotension, peripheral vasospasm, thrombophlebitis.

Monitor blood pressure, pulse and uterine response.

Symptoms: Nausea, vomiting, diarrhoea, extreme thirst, coldness, itching and tingling of the skin, tachycardia, vasospastic reactions, respiratory depression, confusion, convulsions, angina, hypertension, hypotension, coma. Management: Maintain adequate circulation to the affected parts of the body. Vasodilators (e.g. Na nitroprusside) may be administered by IV infusion in case of severe arterial vasospasm. Heparin and dextran 40 may help minimise the risk of thrombosis. For severe ischaemic pain, analgesics may be required.

May enhance the vasoconstrictor/vasopressor effects of triptans (5HT_1B/1D receptor agonists e.g. sumatriptan), sympathomimetics (e.g. local anaesthetics), β-blockers and other ergot derivatives. May potentiate the uterine action of prostaglandins and analogues and vice versa. May reduce the effect of glyceryl trinitrate and other antianginal drugs. Inhalation anaesthetics (e.g. halothane, cyclopropane, desflurane) may diminish the uterotonic effect of ergometrine. Reduced clinical effect with CYP3A4 inducers (e.g nevirapine, rifampicin). May increase the incidence of hypertension, strokes, seizures, and MI associated with the postpartum use of bromocriptine. May interact with dopamine resulting in excessive peripheral vasoconstriction.
Potentially Fatal: Concomitant use with strong CYP3A4 inhibitors such as macrolide antibiotics (e.g. troleandomycin, erythromycin, clarithromycin), HIV protease or reverse transcriptase inhibitors (e.g. ritonavir, indinavir, nelfinavir, delavirdine), or azole antifungals (e.g. ketoconazole, itraconazole, voriconazole) may lead to ergot toxicity.

Description:
Mechanism of Action: Ergometrine is an amine ergot alkaloid that directly stimulates contractions of the uterine and vascular smooth muscles. It increases the amplitude and frequency of uterine contractions and uterine tone, thereby blocking uterine blood flow. Additionally, it increases contractions of the cervix.
Synonym: ergonovine.
Onset: Uterine contractions: 2-7 minutes (IM); immediate or within 1 minute (IV).
Duration: ≥3 hours (IM); approx 45 minutes (IV).
Pharmacokinetics:
Absorption: Rapidly absorbed after IM or IV inj.
Distribution: Crosses the placenta and enters breast milk.
Metabolism: Metabolised in the liver via hydroxylation and glucuronic acid conjugation and possibly, N-demethylation.
Excretion: Via faeces.

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 443884, Ergometrine. https://pubchem.ncbi.nlm.nih.gov/compound/Ergometrine. Accessed June 28, 2022.

Store between 2-8°C. Do not freeze. Protect from light.
Any unused portions should be disposed in accordance with local requirements.

Drugs Acting on the Uterus

G02AB03 - ergometrine ; Belongs to the class of ergot alkaloids. Used to induce abortion or augment labour and to minimize blood loss from the placental site.

Anon. Ergometrine Maleate [Ergonovine]. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 04/04/2022.

Anon. Ergonovine Maleate. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 04/04/2022.

Buckingham R (ed). Ergometrine Maleate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 04/04/2022.

Ergometrine Injection BP 0.05% w/v (Hameln Pharma Ltd). MHRA. https://products.mhra.gov.uk. Accessed 04/04/2022.

Joint Formulary Committee. Ergometrine Maleate. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 04/04/2022.

Pfizer New Zealand Limited. DB Ergometrine Injection data sheet 12 June 2020. Medsafe. http://www.medsafe.govt.nz. Accessed 04/04/2022.