ceftriaxone + metronidazole + aminoglycoside

This is a combination regimen of three antibiotics—ceftriaxone, metronidazole, and an aminoglycoside—used primarily for the empiric treatment of severe intra-abdominal infections and sepsis. - **Ceftriaxone** is a third-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to cell lysis and death[3][4][5]. - **Metronidazole** is a nitroimidazole antibiotic effective against anaerobic bacteria and protozoa; it disrupts DNA synthesis in susceptible organisms[1]. - **Aminoglycosides** (such as gentamicin or amikacin) are bactericidal antibiotics that bind to the 30S ribosomal subunit, inhibiting protein synthesis and causing misreading of mRNA in bacteria[6]. This combination provides broad-spectrum coverage against Gram-positive, Gram-negative (including many Enterobacteriaceae), and anaerobic pathogens. It is commonly used in hospital settings for complicated abdominal infections or sepsis where mixed flora are suspected[2][8].