[Actions of carbocromen of toxic effects of digitalis (author's transl)]

Experiments an anaesthetized dogs, rabbits and guinea pigs show that with clinically relevant doses of 3-(2-diethyl-aminoethyl)-4-methyl-7-(carbethoxy-methoxy)-2-oxo-1,2-chromene-hydrochloride (carbocromen, Intensain¿) the LD100 of digoxin (+50%) and ouabain (+60%) considerably increase. The positive inotropic effect of digoxin is not influenced by carbocromen. The appearance of arrhythmias is significantly delayed, the coupling between atrial and ventricular activity continues for a longer time. Besides effects on myocardial metabolism a membrane effect of carbocromen could be responsible for the improvement of the therapeutic range of digoxin and ouabain.