Randomised Controlled Trial of Oral Nifedipine Vs Intravenous Labetalol in Acute Control Of Blood Pressure In Hypertensive Emergencies Of Pregnancy

Abstract

Objectives: To compare the efficacy of oral nifedipine and IV labetalol in hypertensive emergencies of pregnancy, and their adverse effects Methodology: 100 women with blood pressure greater than 160 mmHg systolic and/or 110 mmHg diastolic were randomized to oral nifedipine or IV labetalol. They were administered drugs until blood pressure was less than or equal to 150 mmHg systolic and 100 mmHg diastolic. The time required to reduce blood pressure to the target value, the number of doses required and the adverse effects were measured. The statistical level of significance was taken at P < 0.05. Results: The patients who came in the inclusion criteria were treated with either nifedipine or labetalol based on their randomization number. It was found that oral nifedipine required 22.55 (± 9.02) minutes where as, Inj. labetalol requires 38.43 (±17.93) minutes to control blood pressure. The P-value was <0.001. This indicates that the difference was highly significant. This study reveals that oral nifedipine acts much quicker than Inj labetalol to reduce blood pressure in hypertensive emergencies of pregnancy. It was also found that nifedipine requires fewer doses than labetalol to achieve the same goal. Oral nifedipine required one dose of 10 mg to reduce blood pressure where as Inj Labetalol required 2 doses, a total of 60 mg to reduce blood pressure to the target level. The p-value calculated was <0.001. Indicating the difference was highly significant. Patients were also monitored for any side effects that may arise from the drugs. The adverse effects noted were, hypotension, dizziness, sweating, flushing, nausea, vomiting, palpitations, headache and fetal tachycardia. Adverse effects observed were very few and of minor degree. There was no statistical difference noted in the adverse effects in both group. Conclusion: Both oral nifedipine and IV labetalol were ultimately effective in reaching the therapeutic goal, but nifedipine achieved the target blood pressure more rapidly and with fewer doses than labetalol. Both drugs demonstrated a similar adverse effects profile. Nifedipine is also cheaper, easier to store, easier to administer as it is given orally, where as IV labetalol is more expensive, needs to be stored at a lower temperature and needs slow IV administration. Thus the present study concludes that Nifedipine is the preferred drug in case of severe pre-eclampsia to control blood pressure as it is more efficacious and can be used in the peripheral centers due to cost effectiveness and its ease of administration and storage. Inj labetalol still has a role in hypertensive emergencies in pregnancy, as it can be used in an unconscious or drowsy patient.