PROTOCOL OUTLINE: This is a randomized, international, multicenter study. Patients are randomized to receive either nimodipine or magnesium sulfate.
Arm I: Patients receive nimodipine by mouth every 4 hours. Treatment is continued until 24 hours post-partum.
Arm II: Patients receive a loading dose of magnesium sulfate IV for 20 minutes, followed by continuous infusion of magnesium sulfate. Treatment is continued until 24 hours post-partum.