Oral Nifedipine or Intravenous Labetalol for Hypertensive Emergency in Pregnancy

Abstract

To compare the effectiveness of orally administered nifedipine and intravenously administered labetalol for acute blood pressure control in hypertensive emergency of pregnancy. In this double-blind, randomized, controlled trial, pregnant women with sustained increase in systolic blood pressure of 160 mm Hg or higher or diastolic blood pressure of 110 mm Hg or higher were randomized to receive nifedipine (10 mg tablet orally up to five doses) and intravenous placebo saline injection or intravenous labetalol injection in escalating doses of 20, 40, 80, 80, and 80 mg and a placebo tablet every 20 minutes until the target blood pressure of 150 mm Hg systolic and 100 mm Hg diastolic, or lower, was achieved. Crossover treatment was administered if the initial treatment failed. The primary endpoint of the study was time necessary to achieve target blood pressure. Secondary endpoints were number of dosages required, adverse maternal and neonatal effects, side effect profile, and perinatal outcome. From October 2012 to April 2013, we enrolled 60 patients. The median time taken to achieve target blood pressure was 40 minutes (interquartile range, 20-60 minutes) compared with 60 minutes (interquartile range 40-85 minutes) for nifedipine and labetalol, respectively (P=.008). The median dose required was two (interquartile range 1-3) compared with three (interquartile range 2-4.25) for nifedipine and labetalol, respectively (P=.008). No serious adverse maternal or perinatal side effects were witnessed in either group. As administered in this trial, oral nifedipine lowered blood pressure more quickly than did intravenous labetalol during hypertensive emergency in pregnancy. Clinical Trials Registry-India, www.ctri.nic.in, CTRI/2013/02/003350. I.