The effects of AN-132, 3-(diisopropylaminoethyl-amino)-2',6'-dimethylpropionanilide.2H 3PO4, on chloroform-induced arrhythmias and plasma digoxin concentrations have been compared with those of quinidine in rats. AN-132 (0.01-3 mg kg-1) administered orally significantly inhibited the incidence of cardiac arrhythmias in a dose-related fashion. A single dose of digoxin (1 mg kg-1) given orally for 7 consecutive days was followed, on day 8, orally by digoxin alone, or together with AN-132 (50, 100 and 200 mg kg-1) or quinidine (25 and 50 mg kg-1). The AUC0-24 and Cmax of plasma digoxin were enhanced significantly by co-administration of quinidine, but not by AN-132.