Comparative study of propranolol, sotalol and INPEA in ouabain-induced cardiac arrhythmias
Nag, D.P.; Chopra, S.C.; Sharma, P.L.
Indian Journal of Medical Research 66(6): 1015-1021
1977
ISSN/ISBN: 0019-5340 PMID: 580429 Document Number: 120581
The prophylactic and curative effects of 3 .beta.-receptor blocking agents, i.e., propranolol, sotalol and INPEA [N-isopropyl-1-(p-nitrophenyl) ethanolamine] against ouabain-induced cardiac arrhythmias were compared in anesthetized dogs and guinea pigs. In the dog, both isomers of propranolol and (-)-INPEA were equally effective in controlling ouabain-induced ventricular tachycardia, while (+).sbd.INPEA and (.+-.) sotalol were not effective. However, upon prophylactic administration all 3 drugs protected the animals from ventricular fibrillation as a terminal event. The decreasing order of potency was propranolol, sotalol and INPEA. In the guinea pigs, all the drugs were effective in abolishing ouabain-induced ventricular tachycardia and in protecting the animals from ventricular fibrillation as the terminal event. The (-)-isomers were somewhat more effective than the (+)-isomers. The study suggested that the membrane activity plays a predominant role and .beta.-receptor blockade contributes to the anti-arrhythmic actions of these drugs in digitalis-induced arrhythmias. The contributon of .beta.-blockade is greater in the guinea pig than in the dog. .beta. blockade plays a predominant role in protection against ouabain-induced ventricular fibrillation.