CONCLUSION
Coadministration of carotegrast methyl with rifampicin, a potent OATP1B1 and OATP1B3 inhibitor, significantly increased the exposure of carotegrast compared with carotegrast methyl administration alone in healthy adults. The active metabolite carotegrast was classified as a sensitive substrate of OATP1B1 and OATP1B3, and carotegrast methyl was a moderate substrate. However, no increase in the incidence of adverse drug reactions due to coadministration with rifampicin was observed.