Efficacy and safety of nifedipine tablets for the acute treatment of severe hypertension in pregnancy.

Abstract

The purpose of this study was to determine whether the slower- and longer-acting nifedipine tablets were as effective and safe as the rapid onset and short-acting nifedipine capsules for the treatment of acute severe hypertension in pregnancy. Sixty-four women in the second half of pregnancy who were not in labor randomly received 10 mg nifedipine tablets (n = 55 studies) or 10 mg nifedipine capsules (n = 74 studies) if blood pressure was > or =170/110 mm Hg. Blood pressure, heart rate, and cardiotocography were monitored over the subsequent 90 minutes. Successful treatment was a target blood pressure of 110 to 169/80 to 109 mm Hg after 90 minutes; unsuccessful treatment included fetal distress at any stage, the requirement for additional treatment (intravenous hydralazine), or the development of hypotension by 90 minutes after treatment. Nifedipine capsules lowered blood pressure further (28/19 vs 21/13 mm Hg; P =.03) than nifedipine tablets, but more than three quarters of each group had a successful treatment. Twice as many women (28%) who received nifedipine tablets required a second dose to achieve successful treatment (P =.05), but fewer women had hypotensive episodes (P =.001). Fetal distress was uncommon in both groups (3%-4%), and both groups were delivered an average of 4 days after the study. Nifedipine tablets, although of slower onset, are as effective as nifedipine capsules for the rapid treatment of severe hypertension in pregnancy.