A nurse is caring for a client who has been given methylergonovine intramuscularly for a postpartum hemorrhage. The nurse should monitor for which of the following adverse effects?

A. Hematuria: Hematuria is not a typical adverse effect of methylergonovine. This medication primarily affects uterine smooth muscle and vascular tone, so urinary complications are uncommon. B. Elevated blood pressure: Methylergonovine is a potent vasoconstrictor, which can lead to hypertension. Monitoring blood pressure is essential because severe elevations can increase the risk of stroke or cardiac complications, especially in clients with preexisting hypertension. C. Uterine relaxation: Methylergonovine promotes uterine contraction, not relaxation. Uterine relaxation would be contrary to the intended therapeutic effect of preventing or controlling postpartum hemorrhage. D. Diarrhea: Gastrointestinal upset, including nausea, vomiting, or diarrhea, can occur but is less common and typically mild. Blood pressure changes are the primary adverse effect requiring close monitoring.