What is "labetalol"

n. A mixed alpha/beta adrenergic antagonist, which is used to treat high blood pressure.

n. antihypertensive drug (trade names Trandate and Normodyne) that blocks alpha and beta-adrenergic receptors of the sympathetic nervous system (leading to a decrease in blood pressure) [syn: labetalol hydrochloride, Trandate, Normodyne]

Labetalol, sold under the trade names Normodyne among others, is a mixed alpha/ beta adrenergic antagonist that is used to treat high blood pressure. It can be given intravenously in severe hypertensive situations, or by mouth for long term hypertension management. Its dose and use is limited by its main side effect— postural hypotension, where there is a substantial drop in blood pressure when standing up.

Labetalol's dual alpha- and beta- blockade has different physiological effects in short and long term situations. In short term, acute situations, labetalol decreases blood pressure by decreasing systemic vascular resistance with little effect on stroke volume, heart rate and cardiac output. During long term use, labetalol can reduce heart rate during exercise while maintaining cardiac output by an increase in stroke volume.