Decreased exposure of some antiretroviral drugs (eg, rilpivirine, atazanavir & nelfinavir). Increased exposure of other antiretroviral drugs (eg, saquinavir). Increased INR & prothrombin time w/ warfarin. May elevate & prolong serum conc of methotrexate &/or its metabolite hydroxymethotrexate, possibly leading to toxicities. Potential for increased exposure of digoxin & tacrolimus. Reduced absorption of drugs dependent on gastric pH for absorption (eg, Fe salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole). Decreased exposure w/ strong CYP2C19 or CYP3A4 inducers (eg, St. John's wort, rifampin, ritonavir-containing products). Increased exposure w/ strong CYP2C19 or CYP3A4 inhibitors (eg, voriconazole).