Giotrif Drug Interactions

P-glycoprotein (P-gp) Interactions: Based on in vitro data, afatinib is a substrate of P-gp. Based on clinical data, concomitant administration of strong P-gp inhibitors or inducers may alter exposure to afatinib. Results of a drug interaction trial demonstrated that GIOTRIF can be safely combined with P-gp inhibitors (such as ritonavir) as long as the inhibitor is administered simultaneously with or after GIOTRIF. If administered prior to GIOTRIF, strong P-gp inhibitors (including but not limited to ritonavir, cyclosporine A, ketoconazole, itraconazole, erythromycin, verapamil, quinidine, tacrolimus, nelfinavir, saquinavir, and amiodarone) may increase exposure to afatinib and should be used with caution. (see Pharmacology: Pharmacokinetics under Actions, Dosage & Administration, and Precautions ).
Strong P-gp inducers (including but not limited to rifampicin, carbamazepine, phenytoin, phenobarbital or St. John's Wort) may decrease exposure to afatinib. (see Pharmacology: Pharmacokinetics under Action and Precautions).
Food Effect on Afatinib: Co-administration of a high-fat meal with GIOTRIF resulted in a significant decrease of exposure to afatinib by about 50% in regard to C_max and 39% in regard to AUC_0-∞. GIOTRIF should be administered without food (see Pharmacology: Pharmacokinetics under Action and Dosage & Administration).