Reduced plasma conc that may result in decreased efficacy w/ CYP3A4 inducers (eg, rifampicin, phenytoin, phenobarb, carbamazepine, St. John's wort), ritonavir & drugs that increase gastric pH (eg, proton pump inhibitors, antacids & H2
-receptor antagonist). Increased exposure w/ CYP3A4 inhibitors (eg, ketoconazole, itraconazole, ritonavir, telithromycin, clarithromycin, nefazodone). Dabigatran etexilate, digoxin. Reduced action of combined hormonal & progestogen-only contraceptives.