Addressing catheter lock therapy: Does heparin reduce the bioactivity of dalbavancin when together in solution during freezing?

Introduction The possible use of dalbavancin as a catheter lock solution was previously demonstrated by our study group. However, it was needed to assess whether heparin could affect dalbavancin bioactivity during freezing storage. Methods We tested the bioactivity of a dalbavancin+heparin (DH) vs. dalbavancin (D) against Staphylococcal biofilms comparing DH median value of cfu counts and metabolic activity with that obtained for D before and during storage under freezing up to 6 months. Results Despite there was a slight decrease in the median percentage reduction of metabolic activity at month 3 in Staphylococcus epidermidis between DH and D (97.6 vs. 100, p=0.037), considering the clinical criteria, no significant reduction in any of the variables tested was observed at the end of the experiment between D and DH solutions. Conclusion The addition of heparin to a dalbavancin lock solution did not affect its bioactivity against staphylococcal biofilms irrespective of its preservation time under freezing.