colistin + rifampicin

Colistin + rifampicin is a combination of two antibiotics used primarily for the treatment of multidrug-resistant (MDR) Gram-negative bacterial infections, especially those caused by *Acinetobacter baumannii*, *Pseudomonas aeruginosa*, and certain Enterobacteriaceae. Colistin (polymyxin E) is a polymyxin antibiotic that disrupts the bacterial outer membrane by interacting with lipopolysaccharides and phospholipids, leading to cell death. Rifampicin (also known as rifampin) inhibits bacterial DNA-dependent RNA polymerase, thereby blocking RNA synthesis. The combination is investigated for its synergistic effects—colistin increases membrane permeability allowing greater intracellular penetration of rifampicin, which can enhance bactericidal activity even against some colistin- or carbapenem-resistant strains. This synergy has been demonstrated in vitro and in animal models; clinical studies suggest potential benefits such as faster microbiological clearance in ventilator-associated pneumonia due to MDR pathogens[1][2][4][5][6]. However, evidence for improved overall clinical outcomes remains limited.

Other names

colistin and rifampicincolistin-rifampicin combinationpolymyxin E + rifampicin