In a patient with preeclampsia, which medication is used to prevent seizures?

• A. Magnesium sulfate
• B. Labetalol
• C. Hydralazine
• D. Nifedipine

Answer: (A)

Magnesium sulfate is used to prevent seizures in preeclampsia because it acts as a central nervous system depressant that lowers neuronal excitability. By reducing the release of acetylcholine at neuromuscular junctions and stabilizing neuronal membranes, it decreases cerebral irritability and helps prevent progression to eclampsia, where seizures occur.

In practice, it’s given IV as a loading dose followed by a maintenance infusion, with careful monitoring of deep tendon reflexes, respiratory rate, and urine output to watch for signs of toxicity. If reflexes are diminished, respiration slows, or urine output drops, the infusion is reassessed and adjusted.

Other medications listed are important for controlling blood pressure in preeclampsia, but they do not provide seizure prophylaxis. They help prevent hypertension-related complications, while magnesium sulfate specifically targets seizure prevention.