Safety and efficacy of urapidil and sodium nitroprusside in the treatment of hypertensive emergencies

Objective: To assess the safety and efficacy of urapidil compared to sodium nitroprusside in the treatment of hypertensive emergencies. Design: randomized, prospective clinical study. Setting: Emergency department in a 2000-bed inner city hospital. Patients: Eighty-one patients with hypertensive emergencies defined as elevation of systolic blood pressure above 200 mmHg and/or diastolic blood pressure above 110 mmHg plus evidence of end-organ damage were included in the study protocol. The efficacy of therapy was defined as 1) blood pressure reduction below 180/95 mmHg within 90 min and 2) no re-elevation of blood pressure during a 4-h follow-up period in primary responders. The safety of both drugs was defined as the number of minor and major side effects during treatment. Interventions: Patients received either sodium nitroprusside (n = 35; continuous intravenous administration with a starting dose of 0.5 mu g/kg per min; increase in increments of 0.5 mu g/kg per min every 15 min until response to treatment or a maximum of 3 mu g/kg per min) or urapidil (n = 46; intravenous bolus; starting dose: 12.5 mg; repetitive administration of 12.5 mg every 15 min until response or a maximum dose of 75 mg). Measurements and results: Blood pressure was measured every 2.5 min by using a non-invasive oscillometric blood pressure measurement unit. Response to treatment within 90 min was observed in 75 (93 %) patients (urapidil: n = 41 [89 %]; nitroprusside: n = 34 [97 %]; p = 0.18). During the follow-up period 8/34 (24 %) patients in the nitroprusside group and 1/41 (2 %) patients in the urapidil group exhibited blood pressure re-elevation. Major side effects were observed in seven patients receiving nitroprusside and two patients in the urapidil group (p = 0.04). Conclusion: Urapidil is equally effective, compared to sodium nitroprusside, in the treatment of hypertensive emergencies. Due to a smaller number of adverse events, urapidil is a reasonable alternative to nitroprusside in the treatment of hypertensive emergencies.