Daptomycin for Pediatric Complex Bone and Joint Infections: Real-world Efficacy and Safety Data from a Three-year Study

Bone and joint infections present a significant therapeutic challenge in children, particularly in complex or chronic cases. Staphylococcus aureus is the most common causative pathogen, with methicillin resistance rates varying by geographic location and hospital setting, underscoring the need for antibiotics effective against both methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. Daptomycin, a cyclic lipopeptide antibiotic effective against gram-positive pathogens, is increasingly used off-label in pediatric osteomyelitis. This prospective study evaluates its real-world application, focusing on clinical outcomes, dosing strategies, safety, and therapeutic potential. Over a 3-year period, 20 children (median age: 13.5 years) with bone and joint infections were treated with daptomycin. The patient cohort was highly complex, with 70% having severe orthopedic or medical comorbidities. Methicillin-sensitive Staphylococcus aureus was isolated in 60% of cases, while MRSA was identified in 35%. Daptomycin was administered following bacteremia dosing guidelines, with some patients receiving higher doses (mean: 10 mg/kg). The median duration of daptomycin therapy was 24.5 days. Treatment was successful in 90% of cases, often transitioning to oral antibiotic therapy. C-reactive protein levels showed a median reduction of 90%. A composite score evaluating clinical response - including C-reactive protein levels, type of continuation therapy, and the need for surgery - indicated substantial improvement in the majority of patients, with a median score of 4. No severe adverse events were recorded, though transient neutropenia and elevated creatine kinase levels were observed in 2 cases. This study underscores daptomycin's safety and efficacy in treating complex pediatric osteoarticular infections and suggests its potential as a first-line therapy, particularly for MRSA cases. The comprehensive data reflect the current microbiological landscape of pediatric bone and joint infections, supporting the reconsideration of daptomycin's role in initial treatment protocols. Further research and controlled trials are warranted to confirm these findings and optimize treatment strategies.