Intravenous labetalol in the management of severe hypertension and hypertensive emergencies.

The intravenous administration of labetalol, a combined alpha- and beta-adrenergic receptor blocking agent, reduced diastolic blood pressure by 30 mm Hg or more in 15 of 17 patients with severe hypertension (supine diastolic blood pressure greater than or equal to 125 mm Hg). A method repeated intravenous injection of the drug produced a prompt but gradual reduction of arterial blood pressure without the induction of a reflex tachycardia. Side effects were mild and of brief duration despite the presence of hypertensive complications in many of these patients. Hypotension, coronary insufficiency, or neurologic deterioration did not occur. Labetalol appears to be a suitable alternative to the direct vasodilating agents in the management of patients with severe hypertension and hypertensive emergencies.