Oral Immediate-Release Nifedipine Versus Intravenous Hydralazine for Controlling Severe Hypertension in Pregnancy: A...

A significant gap exists in understanding the efficacy and safety of oral immediate-release nifedipine and intravenous hydralazine in the control of severe hypertension in pregnancy within the context of randomised control trials.

To compare the efficacy and safety of oral immediate-release nifedipine and intravenous hydralazine for controlling severe hypertension in pregnancy.

Randomised, double-blind, 2-arm, single center non-inferiority trial in pregnant women with confirmed severe hypertension in pregnancy who were randomised in a 1:1 ratio to receive oral immediate-release Nifedipine (n=35) or intravenous hydralazine (n=35) was done from 20^th June 2019 to 20^th December, 2019. The primary outcome was the mean time required to achieve target blood pressure. Secondary outcomes included the mean number of anti-hypertensive doses needed, proportions requiring crossover or rescue therapy, frequency of maternal side effects, fetal heart rate abnormalities, maternal complications, neonatal birth asphyxia, and mode of delivery.

The baseline socio-demographic parameters were similar between the two groups. The mean durations taken to reach the target blood pressure for patients that received oral immediate-release nifedipine versus intravenous hydralazine were 48.29min±31.95 and 41.20min±26.98 respectively (P=0.320). The mean dose used before target blood pressure was reached, the proportion of participants that crossed over to another treatment allocation, and the proportion that required a rescue antihypertensive (labetalol) to achieve the target blood pressure were similar between the two groups (P >0.05). None of the participants that received oral immediate-release nifedipine had maternal or neonatal side effect while one participant (2.9%) that received intravenous hydralazine had nausea and vomiting.

Oral immediate-release nifedipine is as effective as intravenous hydralazine in controlling severe hypertension in pregnancy. Both have remarkable materno-fetal safety profile and its non-invasive nature makes it an appealing modality especially in resource poor countries. More robust studies are encouraged to increase the evidence for its use as first line antihypertensives, especially in low and middle-income countries.

Pan African Clinical Trial registry, PACTR201906662822573, registration date: 19^th June, 2019.