Compatibility and stability of telavancin and vancomycin in heparin or sodium citrate lock solutions

The compatibility and stability of telavancin and vancomycin in heparin or sodium citrate lock solutions were evaluated.

Telavancin and vancomycin hydrochloride injection powder lyophilized for solution were reconstituted with 0.9% sodium chloride injection at room temperature according to the manufacturer's instructions and then further diluted with (1) commercially available heparin sodium to reach a final heparin concentration of 2500 units/mL or (2) sodium citrate solution 2.2% or 4% to achieve final telavancin and vancomycin concentrations of 2 and 5 mg/mL. Physical stability, chemical compatibility, and biological anticoagulant stability were analyzed for each antibiotic-anticoagulant combination immediately after preparation and at 24, 48, and 72 hours. Changes in coagulation were measured at each time point and compared using two-way analysis of variance.

Both telavancin and vancomycin retained at least 90% of the initial concentration after incubation at 37 °C over 72 hours. The biological stability of vancomycin 2 mg/mL and telavancin 2 mg/mL did not significantly alter prothrombin time when compared with that of 0.9% sodium chloride injection. However, telavancin 5 mg/mL and vancomycin 5 mg/mL significantly increased the activated partial thromboplastin time at 72 hours compared with the control solution. Visual precipitation only occurred with vancomycin-containing solutions; however, this dissipated after 10 minutes.

Telavancin 2 and 5 mg/mL was physically compatible in combination with heparin 2500 units/mL and with sodium citrate 2.2% and 4% over 72 hours. Vancomycin 2 and 5 mg/mL initially precipitated in the sodium citrate 2.2% formulation, but no precipitation was noted after 10 minutes of incubation at 37 °C. Telavancin and vancomycin 2 and 5 mg/mL retained over 90% of the initial concentration after incubation at 37 °C over 72 hours.