Randomized controlled trial comparing the efficacy of intravenous labetalol with intravenous hydralazine for the control of severe hypertension in pregnancy

Abstract

Objective: To compare the efficacy and safety of intravenous hydralazine with intravenous labetalol for acute control of severe hypertension in pregnancy at the University of Ilorin Teaching Hospital, Nigeria.Method: The study was a parallel design open-label randomized controlled trial with a ratio of 1:1 involving 160 pregnant women who presented with severe hypertension in pregnancy (160/110mmHg) and were randomized to receive either intravenous bolus hydralazine or labetalol. Women who had live singleton pregnancies with a gestational age of 20 weeks or more with severe hypertension were recruited. The sampling technique was by computer-generated random numbers with blocked randomization. The primary outcome measure was the number of patients that achieved target blood pressure. Secondary outcome measures included need for additional antihypertensive agents and side effects.Results: Both groups had similar baseline parameters (p > 0.05). No significant difference in number of participants between hydralazine and labetalol groups that achieved target blood pressure after the first dose [RR 1.05, CI 0.78 - 1.42; P=0.75], second dose [RR 1.04, CI 0.85 - 1.26; P=0.73], third dose [RR 0.97, CI 0.85 - 1.11; P=0.66], fourth dose [RR 0.95, CI 0.85 - 1.05; P=0.29] and fifth/last dose [RR 0.97, CI 0.91 - 1.05; P=0.47]. However, frequency of adverse effect was significantly higher [27.6% vs 11%, P=0.01] among hydralazine than labetalol group.Conclusion: Incremental Intravenous bolus labetalol is as effective as intravenous bolus hydralazine in rapidly controlling severe hypertension in pregnancy but adverse effects are significantly more common with hydralazine than labetalol.