Comparison of the effects of cetamolol and atenolol on epinephrine- and isoproterenol-induced hypokalemia in anesthetized dogs.

Epinephrine-induced hypokalemia is a beta 2-adrenoceptor-mediated effect known to occur in patients after acute myocardial infarction. Cetamolol and atenolol are beta-adrenoceptor antagonists that possess cardioselectivity. They were studied for their ability to inhibit epinephrine- and isoproterenol-induced hypokalemia in anesthetized dogs at equipotent beta 1-adrenoceptor blocking doses. Cetamolol was able to block epinephrine-induced hypokalemia completely, in a dose-related manner, and to block isoproterenol-induced hypokalemia partially. On the other hand, atenolol could produce only partial blockade of epinephrine-induced hypokalemia in a dose-related manner and had essentially no effect on isoproterenol-induced hypokalemia. These results showed that cetamolol was less cardioselective than atenolol and suggest cetamolol would be more beneficial than atenolol in preventing epinephrine-induced hypokalemia in patients who have an acute myocardial infarction.