Circulating catecholamine that is increased in early phase of myocardial infarction alters serum electrolyte levels which might predispose to serious ventricular arrhythmias. In this study the effect of pretreatment of carvedilol on adrenaline-induced changes in the serum electrolytes (Mg2+, K+, Ca2+, Na+) was evaluated in rats. Adrenaline was administered at a dose of 2 mg/kg body weight subcutaneously 2 injections 24 hours apart and serum electrolytes were estimated at 12 hours, 24 hours and 7 days after the 2nd injection of adrenaline. Adrenaline administration initially caused hypomagnesemia, hypokalemia, hypocalcemia and hyponatremia, which were restored to normal
spontaneously within 7 days. Pretreatment of carvedilol orally at a dose of 1 mg/kg body weight for 2 weeks significantly prevented initial reduction in serum electrolyte levels induced by adrenaline. It was concluded that prophylactic use of carvedilol might prevent the serious consequences of myocardial infarction as sudden cardiac death due to arrhythmia caused by electrolyte changes.