Evaluation of Antihypertensive Efficacy of Intravenous Hydralazine and Intravenous Labetalol in the Management of Severe Preeclampsia and Eclampsia

BACKGROUND Hypertensive disorders of pregnancy are one of the most common obstetrical problems and affect 5-10% of all pregnancies. Severe preeclampsia is a multisystem disorder and causes many complications like intracranial haemorrhage, hypertensive encephalopathy, abruptio placentae, heart failure, pulmonary oedema and eclampsia. Intravenous hydralazine and labetalol are considered as first line antihypertensive agents for management of hypertensive crisis. The objective of this study was to compare efficacy of intravenous hydralazine and labetalol in lowering blood pressure in severe pregnancy induced hypertension, as well as to find out frequency of maternal adverse reactions and foetal impacts. METHODS The study was conducted at Calcutta National Medical College and Hospital over a period of one year. 100 women with severe preeclampsia were included in the study and randomly divided into two groups of 50 each. One group received intravenous hydralazine while the other group was treated with intravenous labetalol. The time and number of doses taken to achieve target blood pressure were noted. Number of patients having persistent severe hypertension after receiving maximum drug dosage were also taken into account. RESULTS The pre-treatment systolic blood pressure was 168.80 mmHg in hydralazine group and 173.64 mmHg in labetalol group whereas the diastolic blood pressure was 143.92 mmHg and 142.6 mmHg in hydralazine and labetalol group respectively. Mean time to achieve blood pressure control was 22.20 minutes in hydralazine group and 26.04 minutes in labetalol group. There were 3 cases of persistent severe hypertension in hydralazine group and 2 cases in labetalol group. No statistically significant difference was found between the two groups in terms of efficacy, maternal adverse effects and perinatal outcome. However, maternal tachycardia and headache was found to be significantly higher in patients treated with hydralazine. CONCLUSIONS Thus, both hydralazine and labetalol are effective and safe antihypertensive drugs which can be used to treat pregnancy induced hypertensive crisis. No significant difference is found between these two agents.