Substances that are potent inhibitors of CYP3A4 activity (eg, ketoconazole and itraconazole) decrease gefitinib metabolism and increase gefitinib plasma concentrations.
<ketoconazole, mechanism, gefitinib>, <ketoconazole, mechanism, gefitinib>, <itraconazole, mechanism, gefitinib>, <itraconazole, mechanism, gefitinib>