Methylergonovine, marketed as Methergine, is an ergot alkaloid used for the prevention and treatment of postpartum hemorrhage caused by uterine atony. It is a second-line agent, used after oxytocin, and its defining nursing concern is its capacity to raise blood pressure, which makes hypertension an absolute contraindication. For this reason, the single most important nursing action associated with this drug is to check the blood pressure before every dose. Postpartum hemorrhage is defined as a cumulative blood loss of 1000 mL or more, or any blood loss accompanied by signs and symptoms of hypovolemia, within 24 hours after delivery. The most common cause is uterine atony, the failure of the uterus to contract firmly after delivery of the placenta, which accounts for roughly 70 to 80 percent of cases. When atony persists despite oxytocin and fundal massage, the provider may add methylergonovine as part of a multi-agent treatment protocol. Methylergonovine produces a sustained, tonic uterine contraction, which is different from the rhythmic contractions produced by oxytocin and is the reason it is used only after the placenta has delivered and...