nafcillin + vancomycin

Nafcillin + vancomycin is a combination of two antibiotics used primarily for the treatment of serious infections caused by Staphylococcus aureus, including methicillin-resistant (MRSA), methicillin-susceptible (MSSA), and heterogeneously vancomycin-intermediate S. aureus (hVISA). Nafcillin is a beta-lactam antibiotic in the penicillin class that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to cell lysis. Vancomycin is a glycopeptide antibiotic that also inhibits bacterial cell wall synthesis but through binding to D-alanyl-D-alanine termini of peptidoglycan precursors, preventing cross-linking and further assembly of the cell wall. The combination has demonstrated synergistic antibacterial activity against hVISA, MRSA, and MSSA strains in both in vitro studies and animal models, often outperforming either drug alone[1][5][10]. This synergy may be particularly beneficial for persistent or difficult-to-treat staphylococcal bacteremia where monotherapy has failed[2].