About sotalolbeta (nonselective) adneregic blocking agent, a potassium channel blocker, anti-hypertensive,class iii anti-arrhythmic.mechanism of action of sotalolsotalol is a non selective beta receptor antagonist. it has negative chronotropic effect on heart. it decreases oxygen consumption- cardiac work and aortic pressure. it increases oxygen supply and exercise tolerance in angina patients. it prolongs duration of monophasic action potentials in atria and ventricles &. prolongs effective refractory period of av node, his purkinje system and all cardiac tissues and av conduction is delayed. it has class 3 antiarrhythmic action of prolonging repolarisation by blocking cardiac k+ channels. it increases ventricular fibrillation threshold in myocardium the drug decreases bp in hypertensive individuals. initially total peripheral resistance increases due to blockade of beta mediated vasodilatation and decrease in cardiac output- so little change in bp.