Effect of rabeprazole on the transport and distribution of levofloxacin in rat stomachs

The aim of this study was to determine the transport and distribution characteristics of levofloxacin in the rat stomach and investigate the effects of combination treatment with rabeprazole. A total of 160 Wistar rats were randomly divided into four treatment groups: 50 mg/kg levofloxacin, 100 mg/kg levofloxacin, 50 mg/kg levofloxacin + rabeprazole and 100 mg/kg levofloxacin + rabeprazole. For two hours after intravenous administration, serum, gastric juice and stomach mucosa samples were collected at 15-min intervals, and the levofloxacin concentrations in all the samples were measured to determine the transport and distribution characteristics of levofloxacin in the rat stomach. In the 50 mg/kg levofloxacin and the 100 mg/kg levofloxacin groups, the drug concentration in the gastric juice gradually exceeded the serum concentration within 45–60 min of administration (P<0.05) and the drug concentrations in the gastric body and antrum were higher than those in the serum and the forestomach (P<0.05). At 15–30 min after administration, the drug concentrations in the gastric juice in the 50 mg/kg levofloxacin + rabeprazole and the 100 mg/kg levofloxacin + rabeprazole groups gradually exceeded the serum concentration (P<0.05). However, the levofloxacin concentration in the gastric body and in the antrum did not significantly differ between the two groups (P>0.05). The levofloxacin concentrations in each stomach region in the groups also treated with rabeprazole were higher than those treated with levofloxacin alone, but the differences were not significant. The levofloxacin transport fractions in the stomach in the 50 mg/kg levofloxacin, 100 mg/kg levofloxacin, 50 mg/kg levofloxacin + rabeprazole and 100 mg/kg levofloxacin + rabeprazole groups were 2.36, 2.52, 2.42 and 2.55, respectively, and no significant difference was identified. Levofloxacin may be actively transported in the rat stomach. The levofloxacin concentration in the gastric antrum exceeded that in the forestomach, and the local concentration increased with increasing dosage. Combining a proton pump inhibitor with levofloxacin has little effect on the concentration and distribution of levofloxacin in the stomach within 2 h.