2008 Abstract : 1

Authors: El Helou O, Berbari E, Lahr B, Eckel-Passow J, Hansen A, Duffy M, Razonable R Sia I, Steckelberg J, Virk A, Walker R, Wilson W,
and Osmon D

Title: Efficacy and Safety of Rifampin(Rf)/Levofloxacin(Lev) for Staphylococcal Prosthetic Joint Infection Treated with Debridement and Retention (D/R)

Institution: Mayo Clinic, Rochester, Minnesota

Purpose: To prospectively evaluate the efficacy and safety of Rf/Lev therapy for S. aureus (SA) or coag.neg. staphylococci (CNS) PJI, total hip arthroplasty or knee arthroplasty treated with D/R and Rf/Lev according to our approved practice guidelines (PG).

Methods: Patients with Rf/Lev susceptible SA or CNS PJI in the prospective study were treated with D/R and oral Rf together with IV antimicrobials for 6 weeks followed by a course of oral Rf/Lev for 3-6 months, then suppressive therapy with an oral antibiotic. The outcome of these patients was compared to patients in the retrospective study treated similarly but with antimicrobial regimens that did not contain Rf in 56 of 87 treated patients. All patients were followed for one year in both the retrospective and prospective cohorts. Cox proportional hazards regression was used to analyze treatment effects on time-to treatment failure (TF) controlling for the propensity to treat with Rf and factors that differed between the prospective and retrospective cohorts.

Results: In the prospective study, 14 episodes of Rf/Lev susceptible SA or CNS PJI were followed prospectively. 1/14 (7%) developed TF. In the retrospective cohort, 21/56 (38%) developed TF. Median duration of chronic suppression was 192 days (140,306 days) and 322 days (6, 365 days) in the prospective and retrospective cohort respectively. Controlling for the propensity to treat with rifampin and American Society of Anesthesia scores, patients with an episode of SA or CNS PJI treated with Rf/Lev in the prospective study had a lower risk of TF when compared to patients in the retrospective study not treated with a rifampin based regimen (HR 0.11; 95%CI 0.01-0.84). None of the patients in the prospective study developed nephrotoxicity or hepatotoxicity.3/56 (5%) patients developed nephrotoxicity in the retrospective cohort.

Discussion and Conclusion: The outcome of Rf/Lev susceptible SA or CNS PJI treated with D/R and rifampin containing regimens was improved when compared with a historical cohort treated without rifampin. There was no toxicity in the prospective cohort.