UNDER REVIEW (September 2016)
Mechanism of Action:
Ergometrine maleate is an ergot alkaloid which probably acts on 5HT and alpha-adrenergic receptors found in the walls of blood vessels and in the uterus. Ergometrine causes constriction of the blood vessels and contraction of the uterus. Intense contraction of the muscles of the uterus causes the blood supply of the placenta (placental bed) to shrink back into the uterus. It also causes shortening and kinking of the blood vessels in the uterus. Contraction of the muscle in the blood vessel walls causes the blood vessels to narrow and reduces blood flow. Both these actions reduce blood loss following delivery. In normal labour, these contractions occur naturally after delivery, to prevent bleeding from the placental blood source. Ergotmetrine is given if this response is deficient allowing post-partum haemorrhage.
Lecture and CAL materials:
- Lecture:
Drug specifics
| Alternative drug name | not specified |
| Effects | Reduces or prevents uterine haemorrhage post-partum. |
| Adverse actions | Nausea, vomiting, headache, dizziness, transient hypertension. It is contraindicated in pre-eclampsia (high blood pressure, protein in the urine and fluid retention in pregnancy). |
| Dose | Intramuscular injection |
| Interactions | May interact with other vasoconstricting drugs. |
| Contraindications | not specified |
| Comments | Oxytocin is another drug with the same function. Ergot alkaloids were first isolated from ergot, a fungus that infects grain. Ergotamine, a closely related ergot derivative, used to be used for migraine. |
| Contributors |
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