Magnesium sulfate versus phenytoin for seizure prophylaxis in pregnancy-induced hypertension

Although pregnant women with hypertension are usually given magnesium sulfate to prevent seizures, it is possible that other anticonvulsants, such as phenytoin, would also be effective. To investigate this further, a prospective, controlled study was carried out with 47 hypertensive patients who are at 36 weeks or more gestation (70 percent were only mildly hypertensive). The subjects were randomly assigned to receive either magnesium sulfate (24 patients) or phenytoin (23 patients) intravenously; blood levels of the drugs were monitored. After delivery, patients and nurses completed questionnaires concerning the side effects of the drugs. The neonatal outcome was also evaluated. Results showed that both drugs were safe and tolerated well by the women. No seizures occurred and no negative neonatal outcomes were noted. The blood levels of free phenytoin (not bound to albumin) were within the therapeutic range in 22 cases, while the total phenytoin levels (free plus bound) were higher than the usual levels in nonpregnant patients. The results show that both phenytoin and magnesium sulfate are safe and effective for seizure prophylaxis. Because less patient monitoring is needed with phenytoin than magnesium sulfate, patients with mild pregnancy-induced hypertension and low risk of seizures may be better suited for phenytoin treatment. (Consumer Summary produced by Reliance Medical Information, Inc.)