colistin sodium methanesulfonate + fosfomycin

This is a combination of two antibiotics—colistin sodium methanesulfonate (also known as colistimethate sodium) and fosfomycin—used primarily for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. Colistin is a polymyxin antibiotic that acts by disrupting the bacterial cell membrane, leading to cell death. It is administered as an inactive prodrug (colistimethate sodium), which is converted in vivo to active colistin[10][5][6]. Fosfomycin inhibits bacterial cell wall synthesis by blocking the enzyme MurA, essential for peptidoglycan biosynthesis. The combination has been studied for synergistic effects against carbapenem-resistant organisms such as Acinetobacter baumannii and Klebsiella pneumoniae, showing improved microbiological eradication rates compared to monotherapy[1][2][3][4]. This regimen is considered when other treatments are ineffective due to resistance.

Other names

colistimethate sodium + fosfomycincolistin methanesulfonate sodium salt + fosfomycin