Clinical Evaluation of Different Doses of Intravenous Enalaprilat in Patients With Hypertensive Crises

BACKGROUND: The appropriate dose of intravenous enalaprilat to be used in the treatment of hypertensive crisis is controversial. There has been no comparative study of the efficacy and safety of different dosages of enalaprilat in hypertensive patients. METHODS: Sixty-five consecutive patients with hypertensive urgencies (systolic blood pressure > 210 mm Hg and/or diastolic blood pressure > 110 mm Hg) or emergencies (diastolic blood pressure > 100 mm Hg and evidence of end-organ damage, ie, angina pectoris, hypertensive encephalopathy, or congestive heart failure) admitted to an emergency department from January 1, 1994, to September 30, 1994, were identified. The patients were randomized to receive different doses of enalaprilat (0.625, 1.25, 2.5, and 5 mg). Response to treatment was defined as a stable reduction of systolic blood pressure to below 180 mm Hg and diastolic blood pressure to below 95 mm Hg within 45 minutes after the start of treatment and relief of symptoms in patients with hypertensive emergencies. RESULTS: In 41 (63%) of 65 patients, the treatment goal was reached. Twenty-four patients (37%) failed to achieve the goal of treatment within 45 minutes after administration of enalaprilat. The response rates in the 0.625-mg, 1.25-mg, 2.5-mg, and 5-mg groups were 67%, 65%, 59%, and 62%, respectively. The proportion of patients initially randomized who responded to treatment was not different between any of the four groups of enalaprilat doses. There were no significant differences according to enalaprilat dose with respect to changes in systolic, diastolic, and mean arterial blood pressure. No severe side effects were observed. CONCLUSION: Enalaprilat is a safe antihypertensive drug with moderate efficacy in the treatment of hypertensive crisis. As doses above 0.625 mg alter neither response rates nor the magnitude of blood pressure reduction, we recommend 0.625 mg as the initial dose in the treatment of hypertensive crisis.