Moxifloxacin plus rifampin as an alternative for levofloxacin plus rifampin in the treatment of a prosthetic joint infection with staphylococcus aureus

OBJECTIVES: The combination of a fluorquinolone with rifampin is one of the cornerstones in the treatment of a prosthetic joint infection (PJI) caused by staphylococci. Moxifloxacin is highly active against methicillin susceptible S. aureus (MSSA), and therefore, an attractive agent to use. However, several studies reported a lowering in serum moxifloxacin levels when combined with rifampin. The clinical relevance remains unclear. We determined the outcome of patients with an early acute PJI caused by MSSA treated either with moxifloxacin/rifampin or levofloxacin/rifampin.

METHODS: Medical files of patients treated with moxifloxacin/rifampin (University Medical Center Groningen) or levofloxacin/rifampin (Hospital Clínic Barcelona) were retrospectively reviewed (2005-2015). Treatment failure was defined as the need for revision surgery and/or suppressive therapy, death by infection or a relapse of infection during follow-up.

RESULTS: Differences in baseline characteristics between both cohorts were observed, but prognostic parameters for failure, as defined by the KLIC-score (Kidney failure, Liver cirrhosis, Index surgery, C-reactive protein and Cemented prosthesis), were similar between both groups (2.9 (1.5 SD) for the moxifloxacin group versus 2.2 (1.2 SD) for the levofloxacin group (p 0.16)). With a mean follow-up of 50 months (36 SD) in the moxifloxacin group, and 67 months (50 SD) in the levofloxacin group (p 0.36), treatment was successful in 89% versus 87.5%, respectively (p 0.89). None of the failures in the moxifloxacin group were due to rifampin or moxifloxacin resistant S. aureus strains.

CONCLUSION: Our data suggest that moxifloxacin combined with rifampin, is as clinically effective as levofloxacin/rifampin for early acute PJI caused by MSSA.