Clinical experience with phenytoin prophylaxis in severe preeclampsia.

In North America, magnesium sulfate is the traditional treatment for severe preeclampsia and eclampsia. Its use has been strongly criticized, in that it acts peripherally with no central effect and maternal and neonatal complications are well known. Phenytoin, the mechanism of action of which is clear, seems a logical alternative. Our aim was to develop a safe, practical, effective regimen with the use of phenytoin. In this prospective, descriptive study four dosage regimens were investigated in 104 patients. The initial regimens produced unexpected and unacceptable side effects in comparison with the nonpregnant population. The final regimen (15 mg/kg intravenously, given as 10 mg/kg initially then 5 mg/kg 2 hours later) provided therapeutic levels and had minimal maternal and perinatal side effects. No seizures occurred after its correct usage. This regimen is simple, safe, effective, and provides ongoing anticonvulsant coverage in the postpartum period. We suggest that phenytoin may represent a suitable alternative anticonvulsant in this condition.