Physical compatibility of vancomycin and piperacillin sodium–tazobactam at concentrations typically used during prolonged infusions

Abstract

The physical compatibility of vancomycin and piperacillin sodium-tazobactam at dosing concentrations commonly administered during prolonged infusions was studied. Concentrations of vancomycin and piperacillin sodium-tazobactam typically used in prolonged infusions were evaluated. Vancomycin hydrochloride and piperacillin sodium-tazobactam were reconstituted with 0.9% sodium chloride injection and diluted to the following concentrations: vancomycin, 4 mg/mL; piperacillin sodium 30 mg/mL plus tazobactam 3.75 mg/mL; and piperacillin sodium 40 mg/mL plus tazobactam 5 mg/mL. Combinations of vancomycin and piperacillin sodium-tazobactam were tested using simulated Y-site administration; phenytoin served as a positive control for precipitation with vancomycin. Each combination was prepared in triplicate, alternating the order of drug addition, and stored without light protection at room temperature. The resultant admixtures were microscopically observed and subjected to particle-size and turbidity analyses for five days. Statistical analyses were performed using two-way repeated measures analysis of variance with conservative Bonferroni corrections for multiple comparisons. Vancomycin was compatible with piperacillin sodium-tazobactam in the concentrations tested. No particulate matter was observed by the unaided eye. Similarly, the antibiotic admixtures displayed no differences microscopically, by particle-size analysis, or by turbidity analysis when compared with negative controls at five days. Vancomycin 4 mg/mL and piperacillin sodium 30 mg/mL plus tazobactam 3.75 mg/mL or piperacillin sodium 40 mg/mL plus tazobactam 5 mg/mL were physically compatible during simulated Y-site injection at room temperature without light protection for five days.