gentamicin + polymyxin

Gentamicin + polymyxin is a compounded combination of two antibiotics, gentamicin (an aminoglycoside) and polymyxin (typically polymyxin B, a polypeptide antibiotic). This combination is not available as a standard commercial product but may be prepared in hospital or pharmacy settings for specific clinical uses, such as bladder irrigation or topical application in the treatment of infections caused by susceptible bacteria. Gentamicin acts by binding to the 30S ribosomal subunit of bacteria, inhibiting protein synthesis and leading to bacterial cell death. Polymyxin disrupts the integrity of the bacterial cell membrane by interacting with phospholipids, particularly in gram-negative organisms, resulting in increased permeability and cell death. Both agents are primarily active against gram-negative bacteria; however, their combined use increases risk for nephrotoxicity and neurotoxicity and should be reserved for special circumstances under close medical supervision[2][5][7].