RT Journal Article
SR Electronic
T1 The effect of the combination of quinidine and propranolol upon atrial and ventricular automatically in dogs.
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 303
OP 311
VO 204
IS 2
A1 Korte, D W
A1 Nash, C B
YR 1978
UL http://jpet.aspetjournals.org/content/204/2/303.abstract
AB The effects of quinidine, propranolol and their combination on atrial and ventricular automaticity were studied in pentobarbital-anesthetized dogs with complete heart block produced by injection of 40% formalin. The indices of atrial and ventricular automaticity were the intrinsic rate and the asystole interval, 10-beat period, and beats per 30 seconds after cessation of a 2-minute overdrive. Potentiation was considered to be a response produced by the combination of a half-dose of quinidine plus a half-dose of propranolol significantly greater than that produced by the full dose of either drug. Two combinations were studied: combination I consisted of 1.0 mg/kg of quinidine and 0.04 mg/kg of propranolol while combination II consisted of 2.0 mg/kg of quinidine and 0.08 mg/kg of propranolol. Neither combination potentiated the action of the individual drugs on the ventricle. Both combinations produced a potentiation of the individual drug effects on atrial intrinsic rate, asystole interval, and 10-beat period while only combination II potentiated the individual drug effects on atrial beats per 30 seconds. These studies indicate that the enhanced effect of the quinidine-propranolol combination in conversion of atrial tachyarrhythmias to sinus rhythm may be a function of its potentiation of the ability of the individual drug to depress atrial automaticity.