Why is methylergonovine contraindicated in patients with chronic hypertension?

• A. It can cause marked hypertension and vasospasm, risking stroke or other complications.
• B. It causes tachycardia.
• C. It causes hypotension.
• D. It is ineffective in controlling postpartum hemorrhage.

Answer: (D)

The main idea is that methylergonovine acts as a uterotonic by causing strong uterine contractions and also constricts vascular smooth muscle. In chronic hypertension, this vasoconstriction can provoke a dangerous rise in blood pressure and vasospasm, increasing the risk of stroke, myocardial ischemia, and other complications. Because of these safety concerns, methylergonovine is avoided in patients with long-standing hypertension, even though it can be effective for controlling postpartum hemorrhage. Clinicians would opt for other uterotonics, like oxytocin or certain prostaglandin analogs, that have a safer profile in hypertensive patients.