Acute treatment of hypertension with slow infusion of diazoxide

We have treated 81 patients who had hypertension with slow intravenous infusion of diazoxide (15 mg/min; 5 mg/kg of body weight). Blood pressure was reduced effectively both in patients with severe hypertension (n = 40) and in patients with a hypertensive crisis (n = 34); the decrease of mean arterial pressure (delta MAP) being -17.0% +/- 1.2% (mean +/- SEM) and -19.7% +/- 1.5%, respectively. However, the delta MAP was significantly greater in patients with preeclampsia (-26.0% +/- 3.0%). In all instances BP fell gradually and then decreased only slightly after discontinuation of the infusion. Thus, the potentially hazardous, steep, and exaggerated fall of BP, observed after bolus injections, can be avoided. Electrocardiographic signs of myocardial ischemia were seen in two patients. No other serious side effects were observed. We conclude that, even in patients with a hypertensive crisis, slow infusion is a safe and effective procedure for the reduction of BP.