Carboprost is a synthetic prostaglandin. It binds the prostaglandin E2 receptor, causing myometrial contractions, causuing the induction of labour or the expulsion of the placenta. Prostaglandins occur naturally in the body and act at several sites in the body including the womb (uterus). They act on the muscles of the womb, causing them to contract.
Carboprost tromethamine administered intramuscularly stimulates in the gravid uterus myometrial contractions similar to labor contractions at the end of a full term pregnancy. Whether or not these contractions result from a direct effect of carboprost on the myome-trium has not been determined. Nonetheless, they evacuate the products of conception from the uterus in most cases. Postpartum, the resultant myometrial contractions provide hemostasis at the site of placentation. Carboprost tromethamine also stimulates the smooth muscle of the human gastrointestinal tract. This activity may produce the vomiting or diarrhea or both that is common when carbo-prost tromethamine is used to terminate pregnancy and for use postpartum. In laboratory animals and also in humans carboprost tromethamine can elevate body temperature. With the clinical doses of carboprost trometh-amine used for the termination of pregnancy, and for use postpartum, some patients do experience transient temperature increases. In laboratory animals and in humans large doses of carboprost tromethamine can raise blood pressure, probably by contracting the vascular smooth muscle. With the doses of carboprost tromethamine used for terminating pregnancy, this effect has not been clinically significant. In laboratory animals and also in humans carboprost tromethamine can elevate body temperature. With the clinical doses of carboprost tromethamine used for the termination of pregnancy, some patients do experience temperature increases. In some patients, carboprost tromethamine may cause transient bronchoconstriction.
Metabolized in the lungs and liver. Metabolites are excreted in urine.
Symptoms of overdose include irritation, nausea, vomiting, diarrhea, coughing, dyspnea, asthma, hypertension, flushing, and pyrexia.