Stability of Antibiotics Used for Antibiotic-Lock Treatment of Infections of Implantable Venous Devices (Ports)

Antibiotic-lock is a treatment for catheter-related bloodstream infections in which a solution containing heparin and an antibiotic dwells in the lumen of the catheter or port. We tested the stability of vancomycin, cefazolin, ticarcillin-clavulanic acid, ceftazidime, or ciprofloxacin combined with heparin after incubation in vitro at 25 or 37°C for intervals of up to 10 days by bioassay. All the antibiotic solutions except ceftazidime retained ≥90% activity at both 25 and 37°C. Thus, studies of antibiotic-heparin lock solutions with dwell times of up to 10 days are feasible.