labetalol + dexmedetomidine

A combination of labetalol and dexmedetomidine used for controlled hypotension during surgical procedures, particularly in functional endoscopic sinus surgery (FESS). Both drugs have distinct mechanisms of action that affect blood pressure and heart rate. Labetalol is a non-selective beta-adrenergic receptor antagonist and selective alpha-1-adrenergic receptor antagonist. It works by blocking these receptors, leading to vasodilation and decreased vascular resistance, which results in lower blood pressure. Following oral administration, labetalol has 3 times more beta-blocking ability than alpha-blocking ability, which increases to 6.9 times following intravenous administration. Dexmedetomidine is a selective alpha-2 adrenoceptor agonist that provides sedation, analgesia, and anxiolysis with minimal respiratory depression. It works by binding to presynaptic alpha-2 adrenoceptors, inhibiting the release of norepinephrine and terminating pain signal propagation. Activation of postsynaptic alpha-2 adrenoceptors inhibits sympathetic activity, decreasing blood pressure and heart rate.