voriconazole + ceftazidime + vancomycin

This is a combination of three antimicrobial agents—voriconazole, ceftazidime, and vancomycin—used together primarily in severe or resistant infections where broad-spectrum antibacterial and antifungal coverage is required. - **Voriconazole** is a synthetic second-generation triazole antifungal that inhibits fungal ergosterol synthesis by blocking the enzyme 14α-sterol demethylase, making it effective against invasive aspergillosis and other serious fungal infections. - **Ceftazidime** is a third-generation cephalosporin antibiotic with strong activity against Gram-negative bacteria (including Pseudomonas aeruginosa) via inhibition of bacterial cell wall synthesis through binding to penicillin-binding proteins. - **Vancomycin** is a glycopeptide antibiotic targeting Gram-positive organisms (notably MRSA), inhibiting cell wall biosynthesis by binding to D-Ala-D-Ala termini of cell wall precursor units. This combination may be used empirically in life-threatening ocular or systemic infections (such as endophthalmitis or febrile neutropenia) when both bacterial and fungal pathogens are possible, especially in immunocompromised patients[1][3]. The use of all three drugs together requires careful monitoring due to potential drug-drug interactions and additive toxicity risks such as nephrotoxicity[1][5].