A 32-year-old patient at 34 weeks’ gestation is admitted for…

A 32-year-old patient at 34 weeks’ gestation is admitted for severe preeclampsia. The patient reports a persistent headache (rated 6/10), epigastric pain, and nausea. Vital signs: BP 164/110mmHg, HR 92 bpm, RR 18 bpm, SpO₂ 98% on room air. Urine dipstick shows +3 proteinuria, and deep tendon reflexes are brisk (3+). Which medication should the nurse prioritize administering?