Experience with High Dose Once-daily Vancomycin for Patients with Skin and Soft-tissue infections in an Ambulatory Setting

BACKGROUND: Intravenous (IV) vancomycin is commonly used to treat MRSA (methicillin-resistant Staphylococcus aureus) infections and is typically dosed at 15 mg/kg every 12 hours. Pharmacokinetic studies, animal models, and limited human study suggest that once-daily high dose (30 mg/kg) vancomycin is similar in efficacy for certain types of infection in the hospital setting, but there is little evidence for its use in outpatient antibiotic therapy (OPAT). We have used a high dose vancomycin regimen for MRSA skin and soft-tissue infections (SSTI) since 2011. We describe our experience with this regimen in an ambulatory setting supervised by Infectious Diseases (ID) physicians and evaluate its efficacy and safety. METHODS: This retrospective observational study included patients treated with vancomycin for SSTI from Jan 1, 2014 to July 31, 2015. Exclusion criteria included noncompliance with treatment. Patients with initial renal impairment were also excluded as they would be given 15 mg/kg vancomycin daily. Patient demographics, response to vancomycin, duration of therapy, readmission to emergency department (ER), and side effects experienced by patients were collected. A successful outcome was defined as no further requirement for IV vancomycin on the last day of therapy with either oral step down therapy or no further antibiotic. RESULTS: 407 charts were reviewed and 208 patients qualified for inclusion. The mean age of included patients was 38 years. Of the 208 patients, 31% were people who inject drugs, 39% had preceding SSTI in the 12 months prior, and 48% had been on antibiotics in the previous 8 weeks. Incision and drainage was done in 50% of the patients. There were 135 positive wound cultures, of which 58% grew MRSA. The average duration of treatment was 4.7 days. A successful outcome was achieved in 162 patients (79%). Side effects including red man syndrome and phlebitis were seen in 19 patients (9.3%). 42 patients (20.5%) were readmitted to ER within 30 days of initial referral, and 18 of those were related to the original infections. CONCLUSION: High dose (30 mg/kg) once-daily vancomycin for SSTI was effective and safe when used for select patients under the supervision of ID physicians in an ambulatory setting. DISCLOSURES: All authors: No reported disclosures.