ORAL ADMINISTRATION OF A P-GP INHIBITORS LIKE RITONAVIR, CYCLOSPORINE A, KETOCONAZOLE, ITRACONAZOLE, ERYTHROMYCIN, VERAPAMIL, QUINIDINE, TACROLIMUS, NELFINAVIR, SAQUINAVIR, AND AMIODARONE 1 HOUR BEFORE ADMINISTRATION OF AFATINIB INCREASED SYSTEMIC EXPOSURE TO AFATINIB BY 48%. THERE WAS NO CHANGE IN AFATINIB EXPOSURE WHEN RITONAVIR WAS ADMINISTERED SIMULTANEOUSLY WITH OR 6 HOURS AFTER AFATINIB.
CO-ADMINISTRATION WITH ORAL DOSE OF A P-GP INDUCER LIKE RIFAMPICIN AT 600 MG ONCE DAILY FOR 7 DAYS & CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, AND ST. JOHN'S WORT DECREASED EXPOSURE TO AFATINIB BY 34%.