A nurse is teaching a client who has chronic migraines about a new prescription for sumatriptan. Which of the following statements should the nurse include in the teaching?

A. "You should take a second dose if there is no relief within fifteen minutes after the initial dose." The second dose of sumatriptan should not be taken sooner than 2 hours after the first dose if there is no relief or if the migraine returns. Taking it too soon increases the risk of adverse effects. B. "You may experience low blood pressure while taking this medication." Sumatriptan more commonly causes hypertension, not hypotension. It can cause vasoconstriction, which may elevate blood pressure and poses risks, especially in clients with cardiovascular disease. C. "You should have complete relief in six hours after taking this medication." Relief from sumatriptan is often experienced within 1–2 hours after administration. While not all clients achieve complete relief, the medication acts quickly, and six hours is not the expected timeframe. D. “You may experience muscle cramps as a potential adverse effect of the medication." Muscle cramps or tightness in the chest, neck, or limbs can occur due to vasoconstriction caused by sumatriptan. This is a known side effect and should be reported if severe or persistent.