colistin + tobramycin

Pre-OP is an oral, non-absorbable antibiotic combination solution containing colistin sulphate (20 mg/mL) and tobramycin (16 mg/mL). Developed by Universitair Medisch Centrum Utrecht (UMC Utrecht), it is specifically designed for the prevention of surgical site infections (SSIs) and postoperative wound infections in patients undergoing elective colorectal surgery. The combination functions as a selective decontamination of the digestive tract (SDD) regimen, targeting gram-negative intestinal bacteria. Colistin, a polymyxin antibiotic, acts by binding to lipopolysaccharides and phospholipids in the outer cell membrane of gram-negative bacteria, leading to membrane disruption. Tobramycin, an aminoglycoside antibiotic, inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Because neither active ingredient is significantly absorbed from the gastrointestinal tract when administered orally, the drug achieves high local concentrations in the gut with minimal systemic exposure, resulting in a favorable safety profile.

Brand names

Pre-OP

Other names

colistin sulphate + tobramycincolistin and tobramycin