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

OBJECTIVE: The purpose of this study was to determine whether the slower- and longer-acting nifecipine tablets were as effective and safe as the rapid onset and short-acting nifecipine capsules for the treatment of acute severe hypertension in pregnancy. STUDY DESIGN: Sixty-four women in the second half of pregnancy who were not in labor randomly received 10 mg nifecipine tablets (n = 55 studies) or 10 mg nifedipine capsules (n = 74 studies) if blood pressure was greater than or equal to170/110 mm Fig. 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. RESULTS: Nifecipine 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. CONCLUSION: Nifedipine tablets, although of slower onset, are as effective as nifedipine capsules for the rapid treatment of severe hypertension in pregnancy.