Alectinib Rifampicin
ModerateRifampicin lowers the amount of Alectinib in the blood. In a study, taking 600 mg rifampicin daily with a single 600 mg Alecensa dose cut Alecensa's peak level by 51% and its overall exposure by 73%. Rifampicin strongly speeds up the CYP3A enzyme that breaks down the drug. Its active by-product M4, which works against ALK about as well, rose 2.20-fold at peak and 1.79-fold in overall exposure.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.