Treating diabetic foot infections with sequential intravenous to oral moxifloxacin compared with piperacillin-tazobactam/amoxicillin-clavulanate

OBJECTIVES: Complicated skin and skin structure infections (cSSSIs), including diabetic foot infections (DFIs), are often polymicrobial, requiring combination or broad-spectrum therapy. Moxifloxacin, a broad-spectrum fluoroquinolone, is approved for cSSSI and can be administered by either intravenous (iv) or oral routes. To assess the efficacy of moxifloxacin for treating DFIs, we analysed a subset of patients with these infections who were enrolled in a prospective, double-blind study that compared the efficacy of moxifloxacin with piperacillin-tazobactam and amoxicillin-clavulanate. METHODS: Patients>or=18 years of age with a DFI requiring initial iv therapy were randomized to either moxifloxacin (400 mg/day) or piperacillin-tazobactam (3.0/0.375 g every 6 h) for at least 3 days followed by moxifloxacin (400 mg/day orally) or amoxicillin-clavulanate (800 mg every 12 h orally), if appropriate, for 7-14 days. DFI was usually defined as any foot infection plus a history of diabetes. Our primary efficacy outcome was the clinical response of the infection at test-of-cure (TOC), 10-42 days post-therapy. RESULTS: Among 617 patients enrolled in the original study, 78 with DFIs were evaluable for treatment efficacy. Clinical cure rates at TOC were similar for moxifloxacin and piperacillin-tazobactam/amoxicillin-clavulanate (68% versus 61%) for patients with investigator-defined infection (P=0.54). Overall pathogen eradication rates in the microbiologically-valid population were 69% versus 66% for moxifloxacin and comparator, respectively (P=1.00). CONCLUSIONS: Intravenous+/-oral moxifloxacin was as effective as iv piperacillin-tazobactam+/-amoxicillin-clavulanate in treating moderate-to-severe DFIs. Moxifloxacin may have potential as a monotherapy regimen for DFIs.