TOXIC INTERACTIONS BETWEEN DISOPYRAMIDE AND PROPRANOLOL IN CHICK-EMBRYOS

The toxic interaction between disopyramide and propranolol were studie d in chick embryos. Fertilized eggs of White Leghorns were incubated a nd investigated, Disopyramide with and without propranolol was injecte d into the air sac of a fertilized egg on thf 16th day of incubation, Electrocardiograms (ECGs) were recorded 0 to 60 min after the injectio n, After each drug injection alone, the heart rate was not different c ompared with control, I-however, the heart rate was significantly decr eased bg combination with disopyramide and propanolol, In addition, ar rhythmia was produced by disopyramide 1.0 mg/egg alone and in combinat ion with propranolol. These findings indicate that the interaction bet ween disopyramide and propranolol has a marked influence on the heart rate in chick embryos.