Objective: To determine the physical compatibility and chemical stability of tacrolimus injection and fluconazole injection combined in a range of concentrations used clinically for intravenous Y-site co-administration over 3 hours.
Design: Tacrolimus injection (Prograf) was combined with fluconazole injection (Diflucan) in volumetric glass flasks at room temperature (23 degrees C to 25 degrees C) to form final concentrations of 5 or 20 micrograms/mL and 500 or 1,500 micrograms/mL, respectively. Immediately after preparation and at 1.5 and 3 hours, triplicate samples and controls were visually inspected and assayed in duplicate by high-performance liquid chromatography; pH of the samples was also determined.
Setting: University of Michigan College of Pharmacy.
Patients: Not applicable.
Interventions: Not applicable.
Main outcome measures: Initial and subsequent concentrations of tacrolimus and fluconazole at 1.5 and 3 hours.
Results: More than 99% of the initial concentration of each drug remained in all samples throughout the study period. There was no color change, and the pH of the samples did not change appreciably.
Conclusion: Tacrolimus and fluconazole are stable and compatible in a range of clinically used concentrations for 3 hours and can be intravenously co-administered through a Y-site.