Comparison of Effects of Labetalol and Hydralazine in Treatment of Hypertension in Patients with Severe Preeclampsia

Document Type : Original Article


1 Associate Professor of Obstetrics and Gynecology, Faculty of Medicine, Women's Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.

2 Resident of Obstetrics and Gynecology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

3 Resident of Internal Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

4 Bachelor of Midwifery, Faculty of Medicine, Women's Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.


Introduction: Hypertension is one of the most common complications of pregnancy which is the main reason of both maternal and perinatal morbidity. Labetalol (both beta and alpha – receptor inhibitor) is an important drug in controlling blood pressure that is rarely used in Iran's gynecology ward of university hospitals. This research was held with the aim of comparing the effects of two medications: hydralazine and Labetalol, in treatment of hypertension in patients with severe preeclampsia.
Methods: This clinical trial study was performed on two hundred women with severe hypertension in pregnancy and gestational age of 28 to 40 weeks from March to December in 2011. They were randomly classified into two groups: receiving hydralazine (5 mg as a slow bolus dose given intravenously, and repeated every 20 min up to a maximum of five doses) and receiving labetalol (20 mg intravenous bolus dose followed by 40 mg if not effective within 20 min, followed by 80 mg every 20 min up to a maximum dose of 300 mg). The main aim was successful lowering of diastolic blood pressure 90 to 100 mm Hg and preventing maternal hypertension. Collected data were analyzed by using SPSS software version 13, chi-square and Mann Whitney Test. P value less than 0.05 was considered statistically significant.
Results: Multivariate analysis revealed no significant differences between two groups (hydralazine and labetalol) in systolic (p=0.619) and diastolic (p=0.888) blood pressure after receiving medications, time of delivery (p=0.903), Apgar score 1minute (p=0.681), Apgar score 5 minute (p=0.639), cesarean section (p=0.659) and abnormal bleeding after delivery (p=0.998) respectively.
Conclusion: Labetalol can be used alternatively instead of hydralazine to control blood pressure in severely hypertensive pregnant women.


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