Labetalol is a competitive antagonist at both alpha1 and beta1-adrenergic receptors. It also has an intrinsic sympathomimetic effect at beta2 receptors

Antihypertensive effects of labetalol results from actions at both alpha1 and beta-adrenergic receptors. Alpha1 receptor blockade results in vasodilatation which is further enhanced by beta2 receptor activation. A reduction in heart rate is mediated by beta-1 receptor antagonism.

Labetalol does not alter serum lipids.

Adverse Effects:

• Orthostatic hypotension may occur due to alpha1 receptor blockade.

• Liver injury has been reported with labetalol usage.