Clindamycin-rifampin Drug Interaction in the Treatment of Bone and Joint Infections

Inclusion Criteria: * age ≥18 years * surgical management of OAI * Postoperative IV antibiotic therapy for 10±2 days * Chronic bone and/or joint infection (evolving for \>4 weeks) with bacteriologically documented staphylococci, streptococci or susceptible anaerobes in skin flora susceptible to clindamycin and rifampin * Continuation of IV administration possible for a maximum of 25 days * Patient consent to participate in the study * Patients entitled enrolled to a French National Health Insurance Exclusion Criteria: * Allergy or intolerance to the family of antibiotics used, i.e. lincosamides (clindamycin, lincomycin) and rifamycins (rifampin), or to one of their constituents * Taking active products able to induce CYP3A4/3A5: alcohol (chronic intake), anti-seizure drugs (carbamazepine, phenobarbital, phenytoin), anti-infectious agents (rifabutin, efavirenz, nevirapine, griseofulvin), anti-fungals (ketoconazole, itraconazole, voriconazole, posaconazole, fluconazole, miconazole), calcium channel blockers (diltiazem, verapamil), macrolides (erythromycin, clarithromycin, josamycin, telithromycin) * Being treated with one of the following: cyclosporine and/or tacrolimus (immunosuppressants) ; midazolam (psychotropic agents) * Human immunodeficiency virus-positive patient being treated with protease inhibitors (ritonavir, amprenavir, atazanavir, indinavir, nelfinavir, lopinavir, saquinavir) or delavirdine * Cirrhosis, hepatocellular insufficiency * Creatinine clearance \< 30 mL/min (according to the cockcroft and gault formula) * Severe sepsis (systolic blood pressure (SBP) \<90 mm Hg; O2 saturation \<90%, encephalopathy, oligo-anuria, creatininemia \>176 mmol/L, platelets \<100,000/mm3, INR \>1.5, Glasgow coma score \<13) or septic shock (persistent hypotension despite volumetric filling) at arrival in the unit * Porphyria * Congenital galactosemia, glucose and galactose malabsorption syndrome, lactase deficit because of the presence of lactose in the dalacin® capsules * Intolerance of fructose, glucose and galactose malabsorption syndrome, sucrase-isomaltase deficit because of the presence of saccharose in the rifadin® capsules * Major cognitive disorders, according to the DSM IV-TR (Diagnostic and Statistical Manual of Mental Disorders) definition (36) * Weight \>100 kg or \<50 kg * Woman of childbearing age using estrogen-progestin contraception and not wanting to switch to an effective mechanical-type contraceptive method * Pregnancy or breast-feeding * Patient under guardianship