isavuconazole + sirolimus

Isavuconazole + sirolimus is a combination of two pharmaceutical drugs: **isavuconazole**, a broad-spectrum triazole antifungal, and **sirolimus**, an immunosuppressant macrolide. - **Isavuconazole** acts by inhibiting fungal lanosterol 14α-demethylase (a CYP51 enzyme), thereby blocking ergosterol biosynthesis essential for fungal cell membrane integrity. - **Sirolimus** exerts its effects by binding to FKBP12 and inhibiting the mechanistic target of rapamycin (mTOR), resulting in blockage of T-cell activation and proliferation. The combination may be used notably in immunocompromised populations, such as transplant patients, for both antifungal prophylaxis/treatment and prevention of graft rejection. Coadministration leads to a pharmacokinetic interaction: isavuconazole inhibits CYP3A4, which in turn increases the serum concentration of sirolimus, requiring monitoring and possible dose adjustment.