Intravenous labetalol in severe hypertension.

1 Labetalol was administered by intravenous infusion or by the combination of intravenous bolus injection plus infusion to 15 patients with severe essential hypertension and to one with phaeochromocytoma. 2 With the infusion alone the reduction of arterial pressure was slow to develop and limited in degree, but with the combination of the bolus injection plus the infusion the reduction in pressure was more prompt, more pronounced and longer lasting. Apart from an uncomplicated syncopal attack in one patient, no serious side--effects were encountered. 3 Subsequent treatment with oral labetalol usually required the addition of a diuretic to control the blood pressure probably due to sodium and fluid retention during treatment with labetalol alone.