Pristinamycin in the treatment of MSSA bone and joint infection-authors' response

Objectives: The aim of this study was to evaluate pristinamycin in the treatment of MSSA bone and joint infection (BJI). Patients and methods: A retrospective, single-centre cohort study (2001–11) investigated outcome in adults receiving pristinamycin for MSSA BJI and pristinamycin-related adverse events (AEs). Results: One hundred and two MSSA BJIs were assessed in 98 patients [chronic infection, 33.3%; and orthopaedic device-related infection (ODI), 67.6%]. Surgery was performed in 77.5% of total cases, and in all but three ODIs, associated with antibiotic therapy of a median total duration of 29.2 weeks. Pristinamycin was prescribed as a part of the initial intensive treatment phase (29.4%) and/or included in final maintenance therapy (83.3%) at a dose of 47.6 (45.5–52.6) mg/kg/day for 9.3 (1.4–20.4) weeks. AEs occurred in 13.3% of patients, consisting of gastrointestinal disorder (76.9%) or allergic reaction (23.1%), leading to treatment interruption in 11 cases. AEs were related to daily dose (OR, 2.733 for each 10 additional mg/kg/day; P1⁄40.049). After a follow-up of 76.4 (29.6–146.9) weeks, the failure rate was 34.3%, associated with ODI (OR, 4.421; P1⁄40.006), particularly when the implant was retained (OR, 4.217; P1⁄40.007). In most patients, the pristinamycin companion drug was a fluoroquinolone (68.7%) or rifampicin (21.7%), without difference regarding outcome. Conclusions: Pristinamycin is an effective, well-tolerated alternative therapeutic option in MSSA BJI, on condition that a daily dosage of 50 mg/kg is respected.