Oxytocics

Oxytocics are drugs that stimulate uterine contractions or increase uterine tone. They are used in obstetrics to induce or augment labor, facilitate delivery of the placenta, and prevent or treat postpartum hemorrhage. Most oxytocics work by activating the uterine oxytocin receptor or by engaging prostaglandin pathways to provoke contractions and cervical changes.

Common oxytocic agents include oxytocin, ergometrine (ergot alkaloids), methylergonovine, carbetocin, misoprostol, dinoprostone, and carboprost tromethamine. Oxytocin is a natural hormone administered intravenously or intramuscularly for induction or augmentation of labor and for postpartum hemorrhage prevention. Ergometrine and methylergonovine are uterotonic ergot derivatives used after delivery to reduce bleeding but can raise blood pressure and are generally avoided in hypertensive patients. Carbetocin is a long-acting oxytocin analog used to prevent postpartum hemorrhage, particularly after cesarean birth. Prostaglandin-based agents such as misoprostol (PGE1), dinoprostone (PGE2), and carboprost (PGF2α) act as uterotonics and are employed for cervical ripening or treatment of atony-related hemorrhage.

Clinical use requires careful monitoring of uterine activity and fetal status. Oxytocics carry risks of uterine tachysystole or hyperstimulation, which can compromise fetal oxygenation, as well as hypertension with ergot derivatives, fever and diarrhea with prostaglandins, and potential fluid balance disturbances with high-dose oxytocin. Absolute contraindications include certain fetal or placental conditions (e.g., fetal distress or placental abruption) and products of conception where induction is not appropriate. Dose, route, and selection depend on the clinical context, including labor induction, augmentation, or postpartum hemorrhage management.