Increased plasma conc w/ strong CYP3A4 inhibitors (eg, clarithromycin, itraconazole, ketoconazole, lopinavir/ritonavir, posaconazole or voriconazole). Avoid grapefruit or grapefruit juice. Decreased plasma conc w/ strong CYP3A4 inducers (eg, carbamazepine, phenytoin, rifampicin, St. John's wort). Interactions w/ substrates of OCT2, MATE1, MATE2-K (eg, metformin) may occur. Interactions w/ P-gp substrates w/ narrow therapeutic index (eg, digoxin or dabigatran etexilate) may occur.