ciprofloxacin + colistin

Ciprofloxacin + colistin is a combination of two antibiotics used primarily for the treatment of infections caused by multidrug-resistant Gram-negative bacteria, especially Pseudomonas aeruginosa. Ciprofloxacin is a second-generation fluoroquinolone that inhibits bacterial DNA gyrase and topoisomerase IV, thereby blocking DNA replication and transcription. Colistin (also known as polymyxin E) is a cationic polypeptide antibiotic that disrupts the bacterial cell membrane through a detergent-like mechanism, leading to cell death. The combination has demonstrated synergistic antimicrobial activity in vitro and in clinical settings, particularly for pulmonary infections such as those seen in cystic fibrosis patients or neutropenic individuals at risk for Gram-negative sepsis. Combination therapy aims to enhance efficacy, reduce resistance development, and minimize toxicity associated with high-dose monotherapy[1][2][5].