Efficacy of oral Labetalol vs Nifedipine in the management of severe hypertension in pregnancy. A Randomized Controlled Trial

Hypertensive disorders in pregnancy (HDP) are leading causes of pregnancy-related morbidity and mortality. International guidelines have recommended the use of intravenous hydralazine or Labetalol in the control of severe HDP. Oral Nifedipine or Labetalol have not been permitted as first-line in managing severe HDP even in low-resource settings where skill for intravenous access is not readily available. This study aimed to determine and compare the efficacy of oral Labetalol versus Nifedipine retard in achieving adequate blood pressure (BP) control among pregnant women with severe Hypertension at Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife.

This was a single-center, open-labeled, randomized controlled trial where 176 eligible pregnant women with severe BP, 30 minutes after Magnesium Sulfate administration, were randomized into Nifedipine and labetalol groups. Each group received either oral Labetalol or Nifedipine retard; 200mg and 20mg, respectively. The second and third doses were subsequently administered after an hour of the initial dose if adequate BP control was not achieved. The mean BP control, doses used, time of achieving blood pressure control, adverse outcomes, and the Effect of co-administration of both oral antihypertensives one hour after the third dose were assessed and compared accordingly. Data was analyzed using SPSS version 26. The efficacy of oral Labetalol versus Nifedipine in controlling BP among the participants was tested using a student’s t-test and chi-square. P-value < 0.05 was taken to be statistically significant.

There was a statistically significant BP control with co-administration of both anti-hypertensive after single agent doses, 70 (86.4%) vs. 65 (80.2%) for the labetalol and Nifedipine groups, respectively (p= 0.003). Participants in the labetalol group used fewer doses cumulatively, with statistical differences at P values of 0.015 and 0.0001 at the first and second doses, respectively. Participants in the labetalol group achieved BP control within a shorter period with minimal adverse outcomes.

Both oral antihypertensives were effective in controlling severe HDP. Oral Labetalol controlled severe Hypertension better with fewer doses, shorter duration, and fewer adverse outcomes; thus, it should be preferred.