Abstract
The effects of enantiomeric bitartrates of disopyramide on blood glucose levels and heart rate were evaluated in Donryu rats. A transient blood glucose lowering response was noted 2 to 3 hr after oral administration of 300 mg/kg d-disopyramide. After oral administration of 1-disopyramide, however, a significant hypoglycemic response was noted which lasted for more than 5 hr. This hypoglycemic action of the individual enantiomers was significantly more potent in the levorotatory form than in the dextrorotatory form, with a relative potency of Pr (d/1) =11.8. The inhibitory effect of the individual enantiomers on the heart rate calculated in vivo from ECG tracings and in vitro from the contraction rate of a right atrial preparation showed no significant difference between the two stereoisomers. These results suggest the possibility of a decrease in the incidence of clinical hypoglycemia while maintaining an acceptable cardiac action by utilizing the dextrorotatory stereoisomer of disopyramide alone.
