doripenem + meropenem + vancomycin

This is a combination of three antibiotics—doripenem, meropenem, and vancomycin—used together for the treatment of severe or resistant bacterial infections.

• Doripenem is a synthetic carbapenem antibiotic with broad-spectrum activity against Gram-positive and Gram-negative bacteria. It acts by inhibiting bacterial cell wall synthesis through binding to penicillin-binding proteins (PBPs), leading to cell lysis and death. Doripenem is particularly effective against many Enterobacteriaceae and Pseudomonas aeruginosa but has limited activity against methicillin-resistant Staphylococcus aureus (MRSA).
• Meropenem is another carbapenem antibiotic with similar broad-spectrum bactericidal activity, also targeting PBPs to inhibit cell wall synthesis. It covers a wide range of Gram-positive and Gram-negative organisms.
• Vancomycin is a glycopeptide antibiotic that inhibits bacterial cell wall assembly by binding tightly to the D-Ala-D-Ala terminus of peptidoglycan precursors, making it especially effective against Gram-positive bacteria including MRSA.

The combination may be used in clinical scenarios where multidrug-resistant organisms are suspected or confirmed, such as hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), complicated intra-abdominal infections, or severe sepsis due to mixed pathogens including MRSA and resistant Gram-negatives. Studies have shown synergistic effects when combining carbapenems like doripenem or meropenem with vancomycin for certain resistant strains such as MRSA.