Ergometrine Other names: Ergonovine maleate

Ergometrine may enhance the vasopressor effects of vasoconstrictors and sympathomimetics, even those contained in local anaesthetics.

CYP3A4 inducers (e.g. nevirapine, rifampicin) may reduce the clinical effect of ergometrine.

Strong CYP3A4 inhibitors such as protease inhibitors, macrolide antibiotics (e.g. troleandomycin, erythromycin, clarithromycin), HIV protease or reverse transcriptase inhibitors (e.g. ritonavir, indinavir, nelfinavir, delavirdine), azole antifungals (e.g. ketoconazole, itraconazole, voriconazole), quinolones might raise the levels of ergot derivatives, which may lead to ergotism. Combined use with Ergometrine should be avoided. Other weaker CYP3A4 inhibitors (e.g cimetidine, delavirdine, grapefruit juice, quinupristin, dalfopristin) might interact similarly, although possibly to a lesser extent.

Prostaglandins and their analogues facilitate contraction of the myometrium hence ergometrine can potentiate the uterine action of prostaglandins and analogues and vice versa.

Concurrent use of other ergot alkaloids (e.g methysergide) and other ergot derivatives can increase the risk of severe and persistent spasm of major arteries in some patients.

Concomitant administration with beta-blockers may enhance the vasoconstrictive action of ergot alkaloids.

Additive vasoconstriction may occur when ergometrine is concomitantly given with triptans (e.g. sumatriptan, zolmitriptan, rizatriptan, almotriptan, eletriptan).

Ergometrine produces vasoconstriction and can be expected to reduce the effect of glyceryl trinitrate and other antianginal drugs.

Inhalation anaesthetics (e.g. halothane, cyclopropane, sevoflurane, desflurane, isoflurane) have a relaxing effect on uterus and produce a notable inhibition of uterine tone and thereby, may diminish the uterotonic effect of ergometrine.

Patients with coronary artery disease may be more susceptible to angina or myocardial ischaemia and infarction caused by ergometrine-induced vasospasm.

Ergometrine has potent uterotonic activity. Therefore, ergometrine is contraindicated during pregnancy, during induction of labour, and during first and second stage labour prior to the delivery of the anterior shoulder.

In breech presentation and other abnormal presentations, ergometrine should not be given before delivery of the child is completed, and in multiple births not before the last child has been delivered.

Ergometrine derivatives are excreted in breast milk but in unknown amounts. There is no specific data available for elimination of ergometrine partitioned in breast-milk. Ergometrine can inhibit prolactin secretion and in turn can suppress lactation, so its repeated use should be avoided.