Pharmacological Interaction of Rifampicin on Clindamycin in Staphylococcic Osteoarticular Infections

Inclusion Criteria: * patients ≥18 years of age * osteoarticular infection * staphylococcus detected in bacteriological sampling * sensibility to rifampicin, erythromycin and clindamycin * active intravenous antibiotherapy against staphylococcus detected in bacteriological sampling Exclusion Criteria: * septic shock or severe initial sepsis * osteoarticular infection with other microorganism than staphylococcus * contraindication to clindamycin or rifampicin including case of hypersensibility to one of these two antibiotics * pre-existing renal insufficiency or severe renal insufficiency (creatinine clearance \<30 ml/min) * serious cognitive disorders * patient under guardianship, trusteeship or non affiliated to social security or CMU (beneficiary or assignee) * refusal to take part in the study and to sign the consent form * pregnancy * lactation * administration of clindamycin or rifampicin within the month before inclusion * treatment with enzymatic inductor or inhibitor within the month before inclusion * participation to another study modifying antibiotic treatment administration