Methylergometrine (maleate)

Methylergometrine maleate (Methylergonovine maleate) is an ergot alkaloid and an active metabolite of Methysergide with vasoconstrictive and uterotonic activity. Methylergometrine maleate is a potent, selective and orally active 5-HT receptors antagonist with a pA₂ value of 9.6. Methylergometrine maleate has antimigraine and dopaminergic activity. Methylergometrine maleate can used for the prevention and control of postpartum hemorrhage^[1][2][3]. IC50 & Target:pA2: 9.6 (5-HT receptors)^[3] In Vitro: Both Methysergide and Methylergometrine displace the concentration-response curve of 5-HT to the right and depressed the maximum effect ; thus, both agents behaved as non-competitive antagonists of 5-HT. Methylergometrine is approximately 40-times more potent than Methysergide as an antagonist of the 5-HT-induced responses, since the calculated apparent pA2 values are 9.6 and 8.0, respectively^[3]. In Vivo: Methylergometrine is more potent than Methysergide as a vasoconstrictor on bovine middle cerebral artery and human coronary arteries, an effect on 5-HT1B receptors. Subacute oral administration would result in metabolism of Methysergide to Methylergometrine^[2].