PIN18 - Clinical comparison of full course intravenous or abbreviated oral antibiotics in hospitalized patients with methicillin-resistant s. Aureus (mrsa) skin and soft tissue infections

Abstract

Orally active MRSA drugs are utilized in hospitalized patients for treatment of skin infections to abridge intravenous (IV) therapy, but clinical evidence of their effectiveness is needed. Our goal was to compare health outcomes in hospitalized adult patients treated with a full course of IV or abbreviated oral antibiotics for MRSA skin infections. This was a single center, retrospective cohort study of hospitalized patients with culture positive MRSA skin infections managed from 2009-2013. Patients were stratified based on receipt of full course IV antibiotics or abbreviated oral antibiotics during the hospital stay. Treatment failure was defined as one of the following within 90 days of initiation of treatment: 1. additional MRSA culture from any site, 2. change in antibiotic therapy, 3. secondary incision and drainage. Statistical analysis included multivariate logistic regression models to assess for predictors of failure. Among 101 patients with MRSA skin infections, 60 received a full course of IV antibiotics and 41 converted to oral antibiotics (minocycline or doxycycline [n=34]). Treatment failure at 90 days was 35%, occurrence of failure was similar among patients with a full course of IV therapy and those abbreviated to oral therapy (21 of 60 [35%] vs. 14 of 41 [34%], p = 0.93). The length of IV therapy was significantly less in patients treated with oral therapy (6.5 days vs 4 days, p< 0.01). In the multivariate adjusted model, treatment with oral antibiotics was not associated with failure. Predictors of failure included Hispanic ethnicity (aOR 15.8; 95% CI, 1.8-138.9, P = 0.01) and a trend towards significance for ulcer skin infections (p = 0.052). Although hospitalized patients are commonly treated with full course IV antibiotics for MRSA skin infections, we found similar outcomes in those converted to oral antibiotics. Treatment failures were associated with Hispanic ethnicity and ulcer skin infections.