erdafitinib + itraconazole

**Erdafitinib + itraconazole** is a combination of **erdafitinib**, a selective pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor, and **itraconazole**, a triazole antifungal agent and strong CYP3A4/P-glycoprotein inhibitor. Erdafitinib is indicated for locally advanced or metastatic urothelial carcinoma with FGFR2/FGFR3 mutations, while itraconazole is primarily used for various systemic fungal infections. When administered together, itraconazole increases the plasma exposure (AUC) of erdafitinib by inhibiting its metabolism through CYP3A4, necessitating dose adjustments due to the risk of increased adverse effects. This combination is not an approved combination product, but represents a clinically relevant drug-drug interaction scenario for pharmacokinetic management in oncology and infectious disease settings[1][2][5][4].