Intravenous Use of Diazoxide in the Treatment of Severe Hypertension

Thirty-three patients with severe hypertension were treated with rapidly injected intravenous diazoxide. Renal function was measured in nine patients and four underwent cardiac catheterization during renal function studies. Diazoxide had a rapid, profound hypotensive effect. Average decrease in mean arterial pressure was 26%, with an average duration of 16 hours. Drug resistance was not observed. Renal function was not impaired despite maintenance of arterial pressure at or near normal levels. Decreased mean arterial pressure was associated with a decrease in systemic vascular resistance and left ventricular end-diastolic pressure while an increase in cardiac index and heart rate occurred. Urine volume was unchanged, whereas the glomerular filtration rate and the effective renal plasma flow increased but urinary sodium excretion decreased markedly. Intravenous diazoxide is a practical effective agent for treatment of all forms of severe hypertension.