Various embodiments relate to catheter locking solutions and catheter locking therapies with use of trisodium citrate and ethyl alcohol, and in particular 4.0 to 15.0 weight/volume % trisodium citrate as an anticoagulant component and/or an antibacterial component and 15.0 to 25.0 volume/volume % ethyl alcohol as an antibacterial component. Use of the catheter locking solution and catheter locking therapy can reduce treatment failure during medical procedures that may employ catheters to supply treatment by at least significantly reducing the risks associated with bloodstream infections, catheter system malfunction, emboli formation, patient discomfort, and patient illness. These benefits can be partially due to the synergistic antibacterial effects of the trisodium citrate and ethyl alcohol in solution, generating an effective catheter locking solution with minimal concentrations of ethyl alcohol.