Labetalol: an alpha- and beta-blocker.

Labetalol is an investigational alpha- and beta- adrenoreceptor antagonist. The ratio of effective beta: alpha-blockade is approximately 7:1. Labetalol, administered intravenously or orally, has been effective in treatment of hypertension, with minimal effects on cardiac output. Labetalol will offer advantages over propranolol due to its more potent antihypertensive effects and less potent effects on left ventricular function at both rest and exercise in patients with coronary artery disease. The drug will be utilized in patients unresponsive to other beta-blocking agents and in patients with congestive heart failure and concomitant hypertension, angina, or arrhythmias when other beta-blockers are contraindicated. The drug appears to be safe in obstructive airway diseases and offers advantages over other beta-blockers in long-term treatment after myocardial infarction.