Nifedipine in acute hypertensive emergencies in pregnancy.

The effect of nifedipine (Adalat; Bayer-Miles)--a calcium channel blocker, which has a well-established place in nonobstetric hypertension--was compared with dihydralazine in 33 primigravidas with severe hypertension of pregnancy. Patients with a diastolic blood pressure greater than 110 mmHg before drug administration were randomly assigned to treatment with either nifedipine or dihydralazine. Both drugs were found to be equally efficacious. Nifedipine, however, showed an earlier onset of action in lowering systolic blood pressure and had the advantage of oral administration.