ergometrine
Table of Contents
ergometrine
see also:
- Oxytocin 10 units is the preferred uterotonic agent for active management of the third stage. It is preferred over other uterotonic drugs as it is effective straight away if administered IV, and within 2 to 4 minutes of administration if given IM. It has minimal side effects and can be used in almost all women (except where there is a history of allergy to oxytocin or carbetocin).
- Do not give ergometrine or combined oxytocin/ergometrine (Syntometrine®) to women with pre-eclampsia, eclampsia or high blood pressure because it increases the risk of convulsions and cerebrovascular accidents.
Introduction
- ergometrine maleate is one of the ergot alkaloids and was discovered in 1932 and isolated in 1935.
- it was originally made from rye ergot fungus
- primarily used as a uterotonic agent to induce uterine contraction and reduce uterine bleeding and was a key factor in reducing maternal mortality in the 20th century, although now largely replaced by oxytocin which has less adverse effects
- effects last 45 - 180 minutes
- it can be used as a precursor for making LSD
Contra-indications
- pregnancy except in ED Mx of 3rd stage of labour but still C/I if other factors present below
- hypertension or precipitous birth where blood pressure not checked
- ensure all babies have been delivered if multiple pregnancy
- cardiac disease
- fibroids
- severe liver impairment
- allergy to ergometrine
Precautions
- Raynaud's
- migraine
- resp. disease
- anaemia
Usual dose
- ergometrine alone
- Ampoule: 500microg/1mL
- Mx of 3rd stage labour if oxytocin is not available and no C/I:
- prevention of PPH: 200-500microg IM after complete delivery of the placenta
- Mx of PPH: 250mcg IM or IV (IV more likely to cause hypertension, nausea and vomiting, give diluted with 5mL 0.9% saline over at least 1 minute)
- combined oxytocin/ergometrine (Syntometrine®)
- Syntometrine® contains oxytocin 5 units & ergometrine 0.5mg
- the oxytocin acts rapidly (within 2 ½ minutes) and is short acting, whilst the ergometrine acts within 6-7 minutes and lasts 2-4 hours.
- Mx of 3rd stage labour if oxytocin is not available and no C/I:
- prevention of PPH: 1 ampoule IM after complete delivery of the placenta
- Mx of PPH: 1 ampoule IM
Mechanism of action
- smooth muscle contraction especially uterine and vascular
- acts at alpha-adrenergic, dopaminergic, and serotonin receptors (the 5-HT2 receptor)
Adverse Effects
- transient hypertension
- nausea, vomiting
- abdominal pain
- diarrhoea
- seizures
- headache, vertigo
- coronary artery spasm (has been used to diagnose variant (Prinzmetal's) angina)
- chest pain
- cardiac arrhythmias
Overdose toxicity
- ergotism or “St. Anthony's fire”:
- prolonged vasospasm resulting in gangrene and amputations
- hallucinations and dementia
- miscarriage if pregnant
- nausea, vomiting and diarrhea
ergometrine.txt · Last modified: 2020/06/01 06:48 by gary1