Introduction: Daptomycin is a concentration-dependent, bactericidal alternative to vancomycin, non-inferior for treatment of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections and endocarditis, with reduced risk of nephrotoxicity and infusion reactions. Dosing varies by indication and patient-specific factors such as renal impairment and obesity, ranging from 4 mg/kg for skin infections to ≥10 mg/kg for vancomycin-resistant enterococci (VRE). Despite longstanding availability, rising VRE prevalence, and frequent use in resistant Gram-positive infections, data on daptomycin prescribing compliance and practice variation remain limited. This study aims to evaluate adherence to dosing recommendations and explore the clinical implications of resistance patterns. Methods: This single-center, retrospective chart review included adults who received intravenous daptomycin between October 2023 and September 2024. Appropriateness was defined by indication, renal function, and weight-based calculations. Descriptive statistics assessed primary and secondary outcomes, including adherence to institutional guidance, pathogen resistance, and anti-MRSA therapy utilization. Results: Seventy patients were included, with a mean age of 57 years; 36% had BMI >30 kg/m2 and 17% had CrCl < 30 mL/min. Patients were primarily treated in critical care settings, most commonly the Trauma-Surgical (11.4%) and Medical Intensive Care Units (10%). Initial dosing was appropriate in 85% (n=60), with highest adherence in endocarditis (90%, 9/10) and osteomyelitis (89%, 8/9). Maintenance dosing was appropriate in 88% (n=62). Among isolates, 71% (20/28) of S. aureus were MRSA and 100% (24/24) of E. faecium were VRE. Anti-MRSA therapy immediately preceding daptomycin initiation occurred in 61% (43/70), while concurrent therapy was infrequent (16%, 11/70). Sixteen patients had a documented vancomycin allergy; of these, 31% experienced infusion reactions. No patients experienced daptomycin-related adverse events. Conclusions: While most daptomycin prescribing aligned with institutional guidance, discrepancies in complex infections and high resistance rates highlight the need for ongoing provider education and antimicrobial stewardship. Optimizing dose selection remains essential to improving outcomes in resistant infections.
Cutler et al. (Sun,) studied this question.