Are there any potential drug interactions with Tarceva?
The potent CYP3A4 inhibitor ketoconazole has been shown to increase erlotinib AUC; thus, caution should be used during co-treatment with Tarceva and ketoconazole or other CYP3A4 inhibitors such as, but not limited to: atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, troleandomycin (TAO) and voriconazole. The CYP3A4 inducer rifampicin has been shown to decrease erlotinib AUC; thus, alternate treatments lacking CYP3A4 inducing activity should be considered. In the absence of an alternative, Tarceva dose modification should be considered during the co-treatment with rifampicin and CYP3A4 inducers such as, but not limited to: rifabutin, rifapentine, phenytoin, carbamazepine, phenobarbital and St. John’s Wort.
The potent CYP3A4 inhibitor ketoconazole has been shown to increase erlotinib AUC; thus, caution should be used during co-treatment with Tarceva and ketoconazole or other CYP3A4 inhibitors such as, but not limited to, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, troleandomycin (TAO), voriconazole, and grapefruit and grapefruit juice. When Tarceva was co-administered with ciprofloxacin, an inhibitor of both CYP3A4 and CYP1A2, the erlotinib AUC increased by 39%. The CYP3A4 inducer rifampicin has been shown to decrease erlotinib AUC; thus, alternate treatments lacking CYP3A4-inducing activity should be considered. In the absence of an alternative, Tarceva dose modification should be considered during co-treatment with rifampicin and other CYP3A4 inducers such as, but not limited to, rifabutin, rifapentine, phenytoin, carbamazepine, phenobarbital, and St. John’s Wort. Drugs that alter the pH of the upper GI tract may alt
