Comparative study of oral nifedipine versus intravenous labetalol in severe hypertension in pregnancy: A randomized controlled study

Abstract

Objective: To compare the efficacy of oral nifedipine with intravenous labetalol in the treatment of severe hypertension in pregnancy. Materials and Methods: It was a double-blind, randomized, controlled study conducted in pregnant women with blood pressure ≥160/110 mm Hg. Total 60 patients were enrolled from October 2016 to September 2017. Patients were randomized to receive nifedipine (10 mg tablet orally up to five doses) and intravenous placebo saline injection or intravenous labetalol injection in doses of 20, 40, 80, 80, and 80 mg and a placebo tablet every 20 minutes until the target blood pressure of ≤ 150/100 mmHg was achieved. The primary outcome of the study was time necessary to achieve target blood pressure. Secondary outcome were number of doses required, onset of labour, mode of delivery, adverse maternal and neonatal effects, side effect, and perinatal outcome. Results: The time to achieve the blood pressure goal was significantly shorter with nifedipine (mean ± SD, 34.67 ± 20.297 minutes) than with labetalol (52.00 ± 29.054minutes; P <0.017). Urine output was significantly increased in nifedipine group (mean ± SD, 2296 ± 210.483 ml) compared with labetalol group (1374 ± 155.798 ml, P < .0001) and remained significantly increased 24 hours after initial administration. No patients required crossover therapy. The adverse effects were infrequent. There were no significant differences in maternal age, gestational age, and blood pressures between the groups. Conclusion: Oral nifedipine and intravenous labetalol both are effective in the management of severe hypertension of pregnancy; however, nifedipine controls hypertension more rapidly with less number of doses and was associated with a significant increase in urinary output.