Administration of outpatient antibiotic therapy (OPAT) among intravenous drug users (IVDUs) is problematic. Factors associated with OPAT failure have not been well elucidated. Our objective was to determine the frequency of OPAT among IVDUs and identify risk factors associated with failure of outpatient therapy in this population.
We reviewed all patients with a history of IVDU on IV antimicrobial therapy who were eligible for hospital discharge between 12/2013 and 12/2015. OPAT failure was defined as worsening or ongoing infection requiring hospital re-admission within 30 days, worsening or ongoing infection at follow-up resulting in therapy extension, premature discontinuation of OPAT, patient noncompliance, or death during treatment.
118 patients were identified; 21% (n=25) were discharged on oral antibiotics, 22% (n=26) remained hospitalized until completion of therapy, and 57% (n=67) were discharged to OPAT. Among OPAT patients (n=67), 53% were men, 92% were Caucasian, and the median age was 34.5 years (range: 19-62). Median Charlson Comorbidity Index was 1.5 (0-8). Underlying infections included endocarditis (54%), epidural abscess (15%), osteomyelitis (13%), or other infections (18%). Causative pathogens were S. aureus (69%; [46% MSSA, 22% MRSA]) and viridans streptococci (7%). Vancomyin (34%), nafcillin (31%), and cefazolin (9%) were the most commonly administered agents. 26% of patients received other agents. 62% of patients followed up in OPAT clinic during their treatment duration. Overall, 61% failed OPAT. Reasons for failure included noncompliance (n=20), 30-day readmission (n=15), worsening or ongoing infection at follow-up (n=4), and death during treatment (n=2). The median time since last IVDU was shorter among patients who failed versus completed OPAT (3 weeks vs 8 weeks; P=0.02). By multivariate analysis, time since last IVDU was independently associated with OPAT failure (P=0.04).
IVDUs are at high risk for OPAT failure. Accordingly, only 57% of eligible patients were discharged with IV therapy. Patients should be aggressively screened to determine risks for ongoing IVDU prior to hospital discharge.
N. Shah, None
C. Shoff, None
K. Sheridan, None