Oxytocin + Ergometrine


Generic Medicine Info
Indications and Dosage
Intramuscular
Treatment and prophylaxis of postpartum haemorrhage
Adult: Available preparation:
Each 1 mL solution contains oxytocin 5 IU and ergometrine maleate 500 mcg

1 mL after placental expulsion or in the occurrence of bleeding. Doses may be repeated after ≤2 hours. Max: 3mL daily.

Intramuscular
Active management of the third stage of labour
Adult: Available preparation:
Each 1 mL solution contains oxytocin 5 IU and ergometrine maleate 500 mcg

Administer 1 mL after delivery of the anterior shoulder or immediately after delivery of the infant.
Renal Impairment
Severe: Contraindicated.
Hepatic Impairment
Severe: Contraindicated.
Contraindications
Labour induction, 1st or 2nd stage of labour prior to the delivery of anterior shoulder, primary or secondary uterine inertia, severe cardiac disease, severe hypertension, pre-eclampsia, eclampsia, occlusive vascular disease, sepsis. Severe renal and hepatic impairment. Pregnancy.
Special Precautions
Women with mild to moderate hypertension, CV disease (e.g. coronary artery disease), long QT syndrome, Raynaud’s phenomenon. Mild to moderate renal and hepatic impairment. In cases of breech and other abnormal presentations, this medicine should not be given until after delivery of the child or in multiple births until the last child has been delivered.
Adverse Reactions
Significant: Angina, myocardial ischaemia, MI, anaphylaxis.
Cardiac disorders: Chest pain, bradycardia, arrhythmia.
Gastrointestinal disorders: Nausea, vomiting, abdominal pain.
Immune system disorders: Angioedema.
Nervous system disorders: Dizziness, headache, cerebrovascular accident.
Respiratory, thoracic and mediastinal disorders: Dyspnoea.
Skin and subcutaneous tissue disorders: Rash.
Vascular disorders: Hypertension, hypotension.
Overdosage
Symptoms: Ergometrine: Nausea, vomiting, respiratory depression, hypotension or hypertension, vasospastic reactions, convulsion, coma. Management: Symptomatic treatment. Activated charcoal may be given within 1 hour of ingestion of a toxic dose. Alternatively, may consider gastric lavage within 1 hour of ingestion of a potentially life-threatening overdose. Maintain adequate circulation to prevent onset of gangrene. Administer vasodilators (e.g. Na nitroprusside) to treat severe arterial vasospasms. Give heparin and dextran 40 to reduce the risk of thrombosis. To treat severe ischaemic pain, administer analgesics.
Drug Interactions
Increased vasopressor action of vasoconstrictors and sympathomimetics. Enhanced uterine action of prostaglandins and vice versa. Diminished uterotonic effect with inhalation anaesthetics (e.g. halothane, cyclopropane, isoflurane, desflurane, sevoflurane).
Oxytocin: Increased risk of arrhythmia with drugs that prolong QT interval.
Ergometrine: Reduced therapeutic effect with CYP3A4 inducers. Increased risk of ergot toxicity with CYP3A4 inhibitors (e.g. erythromycin, clarithromycin, ritonavir, indinavir, nelfinavir, delavirdine, ketoconazole, itraconazole, voriconazole, cimetidine). Enhance vasopressor effects of triptans. Potentiated vasoconstrictive action with β-blockers. Diminished therapeutic efficacy of glyceryl trinitrate and other antianginal drugs.
Food Interaction
Increased ergometrine plasma concentration with grapefruit.
Action
Description: Oxytocin and ergometrine acts on the uterus via different but complimentary mechanisms.
Oxytocin, a cyclic nonapeptide, activates G-protein-coupled receptors at the uterus which causes an increase in intracellular Ca levels in uterine myofibrils, thus promoting uterine contractions.
Ergometrine, an ergot alkaloid, acts on the 5-HT2 and α-adrenergic receptors to produce a sustained tonic uterine action.
Synonym: ergonovine.
Onset: Oxytocin: IM: 3-5 minutes.
Ergometrine: 2-5 minutes.
Duration: Oxytocin: 2-3 hours.
Ergometrine: ≥3 hours.
Pharmacokinetics:
Absorption: Rapidly absorbed after IM administration.
Distribution: Crosses placenta, enters breast milk.
Metabolism: Oxytocin: Metabolised in the liver and kidneys.
Ergometrine: Metabolised in the liver.
Excretion: Via urine as unchanged drug.
Oxytocin: Elimination half-life: 3-20 minutes.
Ergometrine: Elimination half-life: 30-120 minutes.
Chemical Structure

Chemical Structure Image
Oxytocin

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 439302, Oxytocin. https://pubchem.ncbi.nlm.nih.gov/compound/Oxytocin. Accessed Nov. 25, 2020.


Chemical Structure Image
Ergometrine

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 443884, Ergonovine. https://pubchem.ncbi.nlm.nih.gov/compound/Ergonovine. Accessed Nov. 25, 2020.

Storage
Store between 2-8°C. Protect from light.
ATC Classification
G02AC - Ergot alkaloids and oxytocin incl. analogues, in combination ; Used to induce abortion or augment labour and to minimize blood loss from the placental site.
References
Anon. Ergonovine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 01/10/2020.

Anon. Oxytocin and Ergometrine Maleate. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 01/10/2020.

Anon. Oxytocin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 01/10/2020.

Buckingham R (ed). Ergometrine Maleate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 01/10/2020.

Buckingham R (ed). Oxytocin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 01/10/2020.

Joint Formulary Committee. Ergometrine with Oxytocin. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 01/10/2020.

Syntometrine (Rotexmedica GmbH). MIMS Singapore. http://www.mims.com/singapore. Accessed 01/10/2020.

Syntometrine 500 micrograms/5 IU Solution for Injection (Alliance Pharmaceuticals Ltd). MHRA. https://products.mhra.gov.uk/. Accessed 01/10/2020.

Disclaimer: This information is independently developed by MIMS based on Oxytocin + Ergometrine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by MIMS.com
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