IV labetalol and oral nifedipine in acute control of severe hypertension in pregnancy-A randomized controlled trial.

Objective: To compare the efficacy of intravenous labetalol with oral nifedipine in the treatment of severe hypertension in pregnancy with blood pressure ≥160/110 mm Hg.

Design, Setting And Participants: We conducted a parallel double-blinded randomized controlled trial between December 2014 to December 2016 in 120 antenatal women of gestational age >28 weeks, admitted with severe hypertension of blood pressure ≥160/110 mm Hg to maternity ward at a tertiary hospital. The labetalol group received 20 mg initially followed by escalating doses of 40 mg, 80 mg, 80 mg and 80 mg (5 doses) every 15 min to a maximum of 300 mg. Nifedipine group received 10 mg initially followed by repeated doses of 20 mg every 15 min (total 5 doses) to a maximum of 90 mg. Vital signs were recorded every 15 min. -The time taken and the number of doses required to achieve the target blood pressure (150/100 mmHg). Survival analysis was used to compare the efficacy of treatment regimens.

Results: Sixty women were randomised to each group and none were lost to follow-up. None of the patients in nifedipine group required labetalol, whereas three patients in labetalol group achieved target BP only after receiving nifedipine was administered after the maximum dose of labetalol.The mean time taken to achieve the target blood pressure in the labetalol group was higher (36.75 min) than in the nifedipine group (27.25 min) [mean difference 9.5 min,p = 0.002]. Nifedipine group required significantly lower doses (1.82 ± 0.83) as compared to labetalol (2.45 ± 1.32) [p = 0.002]. Nifedipine was 1.8 times more likely to achieve target blood pressure (Hazard Ratio = 1.8).

Conclusions: Both intravenous Labetalol and oral Nifedipine were effective in controlling blood pressure. Nifedipine reduced BP more rapidly than Labetalol. Oral Nifedipine may be a better alternative because of its ease of oral administration and a flat dosing regimen.