Medical articles impregnated with antimicrobial compositions containing synergistic combinations of octoxyglycerin and other anti-infective compounds are disclosed. Such medical articles may include urinary catheters, central venous catheters, tracheal catheters, arterial grafts, wound dressings, sutures, or any other medical articles derived from polymeric substrates such as biomedical polyurethane, biomedical polyvinylchloride (PVC), biomedical silicon, biodegradable polymers, polytetrafluoroethylene (PTFE), etc. or from natural products including natural rubber, silk or cotton fiber. Antimicrobial compositions comprising salicylic acid and sesquiterpenoids are also disclosed.