Ketoconazole Erlotinib

ERLOTINIB ANTIFUNGALS - FLUCONAZOLE, ITRACONAZOLE, KETOCONAZOLE VORICONAZOLE t erlotinib levels 1 metabolism of erlotinib Avoid co-administration... 

The metabolism of erlotinib is markedly affected by other drugs that are potent inhibitors (e.g. ketoconazole) or inducers (e.g. ri-fampicin) of the cytochrome P450 isoenzyme CYP3A4. Alternatives to these drugs should be used where possible if not, alteration of the dose of erlotinib is required. The concurrent use of temozolomide may either reduce or increase erlotinib levels, depending on the dose of erlotinib. Smoking increases the metabolism of erlotinib. 

The AUC of erlotinib has been found to be increased by 66% when given with ketoconazole 200 mg twice daily for 5 days. The manufacturers advise caution with concurrent use, and recommend that the dose of erlotinib should be reduced if severe adverse reactions occur when given with strong CYP3A4 inhibitors. They specifically name atazanavir, clarithromycin, erythromycin, grapefruit and grapefruit juice, indinavir, itraconazole, ketoconazole, nefazodone, neltinavir, ritonavir, saquinavir, telithromycin, troleandomycin and voriconazole. ... 

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