Propranolol

Propranolol is a nonselective β₁- and β₂-adrenergic receptor antagonist available in both IV and oral forms. Propranolol is highly lipophilic; it is almost entirely absorbed following oral administration and undergoes up to 75% first-pass clearance by the liver. Hemodynamic effects of propranolol and other β-adrenergic antagonists are secondary to the reduction of cardiac output and suppression of the renin–angiotensin system. β-Adrenergic antagonists can be distinguished by their relative β₁ selectivity, their intrinsic sympathomimetic activity, and their pharmacologic half-lives.