Effects of clarithromycin and amoxicillin on gastric emptying in rats

The effects of oral administration of clarithromycin (CLR), amoxicillin (AMX), and lansoprazole (LPZ) on gastric emptying in rats were investigated by a glass powder method and a phenol red method. By both test methods, no significant effects on gastric emptying were observed when CLR, AMX, or LPZ was administered alone or when the three drugs were administered concomitantly. The levels of gastrointestinal absorption of [(14)C]CLR and [(14)C]AMX were measured. Four hours after injection of [(14)C]CLR or [(14)C]AMX into the stomach and duodenum loops of rats, 86.63 and 1.27% of the original amount of [(14)C]CLR administered were recovered in the contents of the stomach and duodenum loops, respectively, and 80.01 and 55.88% of the original amount of [(14)C]AMX administered were recovered in the contents of the stomach and duodenum loops, respectively.