Ceritinib has the potential to interact with medicinal products that are metabolised by CYP3A, which may lead to increased serum concentrations of the other product.
Co-administration of a single dose of warfarin (a CYP2C9 substrate) following 3 weeks of ceritinib dosing in patients (750 mg daily fasted) increased the S-warfarin AUCinf (90% CI) by 54% (36%, 75%) compared to warfarin alone. Co-administration of ceritinib with substrates primarily metabolised by CYP2C9 or CYP2C9 substrates known to have narrow therapeutic indices (e.g. phenytoin and warfarin) should be avoided.