Carbetocin is a drug used to control postpartum hemorrhage, bleeding after giving birth. It is an analogue of oxytocin, and its action is similar to that of oxytocin -- it causes contraction of the uterus. (en)
Carbetocin binds to oxytocin receptors present on the smooth musculature of the uterus, resulting in rhythmic contractions of the uterus, increased frequency of existing contractions, and increased uterine tone. The oxytocin receptor content of the uterus is very low in the non-pregnant state, and increases during pregnancy, reaching a peak at the time of delivery. (en)