Prescribing Patterns And Patient Outcomes For Bone And Joint Infections Treated With Cefazolin And Probenecid: A Retrospective Observational Study

Background: Previous studies have described the use of cefazolin with probenecid to treat uncomplicated skin and soft-tissue infections. Some prescribers are extrapolating from this evidence to treat more invasive infections, which have a greater potential for poor outcomes, including treatment failure that could lead to increased morbidity and mortality. Information supporting cefazolin with probenecid as effective treatment in this context is needed.Objectives: To describe prescribing patterns and outcomes for patients who received cefazolin with probenecid for the treatment of bone and joint infections.Methods: This single-centre retrospective study involved adult outpatients for whom cefazolin and probenecid were prescribed for bone and joint infections between April 1, 2012, and March 31, 2017. Patient charts were reviewed, and data were collected for clinical and microbiological variables using a standardized data collection form.Results: In a total of 80 cases, the patient received cefazolin and probenecid for treatment of a bone or joint infection, of which 69 cases met the inclusion criteria. In most cases (n = 67), the patients were treated with cefazolin 2 g IV plus probenecid 1 g PO, both given twice daily. Completion of prescribed treatment occurred in 56 patient cases (81%), resolution of signs and symptoms in 53 (77%), readmission to hospital in 11 (16%), recurrence of infection in 6 (9%), and treatment failure requiring a change in therapy in 7 (10%).Conclusions: The effectiveness of cefazolin and probenecid for the treatment of bone and joint infections appears to be similar to that of standard treatment, as reported in the literature. Antibiotic effectiveness is difficult to determine conclusively in a retrospective analysis, so these results should be interpreted with caution, but they may stimulate further research.