Treatment of Methicillin-sensitive Staphylococcus Aureus (MSSA)

Background: One of the leading causes of peri-operative osteoarticular infections (OAI) is Staphylococcus aureus. Treatment usually requires surgical debridement in association with appropriate antibiotic therapy. After surgery, an intravenous (IV) antibiotic therapy is routinely indicated for 10 to 15 days, followed by a minimal one-month oral treatment. In this protocol, the latter includes clindamycin in combination with rifampin or levofloxacin. Clindamycin is considered a good option in staphylococcal infections, because of its action against biofilm formation and bacterial adherence, its high level of joint and bone penetration and its good tolerance. Rifampin, a potent cytochrome P-450 inducer, enhances the elimination of a large number of drugs. Therefore, an influence of rifampin on clindamycin pharmacokinetics must be considered. Objectives: The primary objective is to compare the influence of rifampin and levofloxacin respectively on the pharmacokinetics of clindamycin in a randomized series of peri-operative staphylococcal OAI. The investigators then seek to determine the optimal drug association with regard to infection control and drug tolerance. Study design: Monocentric, randomized, open label, comparative study Study period: From November 2010 to October 2011. Materials and Methods: Following surgical debridement and after 10 to 15 days of IV antibiotherapy, patients are randomly assigned either to the "clindamycin/rifampin" arm either to the "clindamycin/levofloxacin" arm, according to the antimicrobial susceptibility testing. Peak and trough serum concentrations of clindamycin are measured at day-1, day-15 and day-30 of oral treatment. Rifampin and levofloxacin serum concentrations are measured at the same intervals to monitor patient compliance.