Effect of diammonium glycyrrhizinate on entecavir pharmacokinetics in rats

Aim: This study was designed to explore the effects of short-term and long-term pretreatment of diammonium glycyrrhizinate (GLN) on the pharmacokinetics of entecavir (ETV) in rats. Methods: Male SD rats were randomized into short-term and long-term experimental groups, respectively. In the short-term experiment, the control group received saline, the low dose group received GLN 13.5 mg·kg^-1 and the high dose group received GLN 40.5 mg·kg^-1. ETV (0.09 mg·kg^-1) was given i.g. 0.5 h after saline/GLN administration. For the long-term experiment, rats were allocated into two experimental designs. The control group received saline/ETV (0.09 mg·kg^-1), the low dose group received GLN 13.5 mg·kg^-1/ETV 0.09 mg·kg^-1 + GLN 13.5 mg·kg^-1, while the high dose group received GLN 40.5 mg·kg^-1/ETV 0.09 mg·kg^-1 + GLN 40.5 mg·kg^-1; all administration was continued for 15 days. On the 16^th day, 0.09 mg·kg^-1 ETV was administrated to all groups. Blood samples were obtained at different time points after ETV administration to determine plasma ETV concentrations. Results: Pretreatment with glycyrrhizin resulted in no significant alterations in the main pharmacokinetic parameters of ETV in the short-term and long-term administration experiments. Conclusion: Diammonium glycyrrhizinate has no effect on ETV pharmacokinetics in rats.