Subcutaneous Suppressive Antibiotic Therapy for Bone and Joints Infections: Safety and Outcome in a Cohort of 10 Patients

BACKGROUND: Optimal surgical therapy could be sometimes non-feasible, especially in the elderly population. Therefore, a medical therapy with oral prolonged suppressive antibiotic therapy (PSAT) seems to be an option to prevent recurrence and prosthesis loosening. Subcutaneous (SC) administration of injectable intravenous antibiotics as PSAT could be a convenient way when oral treatment is not available to facilitate ambulatory care, even if this practice is considered as an “off-label” practice. METHODS: All patients receiving SC PSAT since 2010 were prospectively enrolled in a cohort study evaluating treatment modalities, efficacy, and safety. Success was defined by the absence of clinical signs of infection at the time of last follow-up. RESULTS: We included 10 patients (median age of 79 years): seven had PJI and three chronic osteomyelitis. Six had plurimicrobial infections and four had infections due to multidrug-resistant Gram-negative pathogens. Suboptimal surgery was performed in seven patients, and three received only antibiotics. All patients received an induction-phase therapy with conventional antibiotic treatment before SC PSAT. For nine patients, SC injections were delivered by a 50 mlml 30 minute gravity infusion of the antibiotic, using butterfly disposable needle. One patient received direct flash SC administration. The most frequent drug used was ertapenem (n = 7; 1–2 g/day), followed by ceftriaxone (n = 2; 1 g/day), and ceftazidime (n = 1; 2 g/day). The dose was adjusted depending on the results of trough residual blood concentration. Median duration of treatment was 6 months (from 1 to 58 months), corresponding to a total of about 5,000 SC injections. SC PSAT had to be discontinued for side effects in only two patients, including skin necrosis in the patient receiving direct SC infusion (lost to follow-up after treatment discontinuation) and epilepsy under ertapenem therapy (with relapse of the BJI after the treatment discontinuation). One other patient experienced a relapse despite the SC PSAT. Finally, SC PSAT was still ongoing in seven patients with a favorable outcome at the last follow-up. CONCLUSION: SC PSAT appears to be a safe and effective alternative therapy when optimal surgical strategy is not feasible and when oral treatment is not available. DISCLOSURES: T. Ferry, HERAEUS: Consultant, Speaker honorarium. S. Lustig, Heraeus: Consultant, Consulting fee