Clinical experience with daptomycin treatment of foot or ankle osteomyelitis: a preliminary study

We retrospectively reviewed 25 patients with foot or ankle osteomyelitis reported to a registry who were treated with daptomycin. The patients' clinical experience was analyzed and described at a median dose of 6 mg/kg (range, 4-6.2 mg/kg) and a median duration of 38 days (range, 6-59 days). Twenty-three patients received daptomycin as secondary or tertiary therapy, primarily for not responding to their prior antibiotic therapy (n = 15). Concomitant antibiotics were given to 11 patients, mostly for Gram-negative and/or anaerobic coverage. Methicillin-resistant Staphylococcus aureus was the most common pathogen overall (15 of 25 patients). The median followup interval was 9 weeks (range, 0.5-77 weeks). Outcomes at the end of therapy were 16 patients' symptoms resolved, eight patients improved, and one patient did not respond to therapy; at followup, 19 patients' symptoms resolved, three patients improved, and three patients did not respond to therapy. Ongoing antibiotics were given to 52% of patients for a minimum of 8 days (median, 30 days; range, 8-232 days). Four patients with an implant (all removed) were successfully treated. Daptomycin appears promising for foot and ankle osteomyelitis caused by Gram-positive bacteria. Prospective, controlled clinical trials of daptomycin for osteomyelitis are warranted.