Evaluation of partial oral antibiotic treatment for persons who inject drugs and are hospitalized with invasive infections

Background. Persons who inject drugs (PWID) are at risk of invasive infections; however, hospitalizations to treat these infections are frequently complicated by against medical advice (AMA) discharges. This study compared outcomes among PWID who (1) completed a full course of inpatient intravenous (IV) antibiotics, (2) received a partial course of IV antibiotics but were not prescribed any antibiotics on AMA discharge, and (3) received a partial course of IV antibiotics and were prescribed oral antibiotics on AMA discharge. Methods. A retrospective, cohort study of PWID aged ≥18 years admitted to a tertiary referral center between 01/2016 and 07/2019, who received an infectious diseases consultation for an invasive bacterial or fungal infection. Results. 293 PWID were included in the study. 90-day all-cause readmission rates were highest among PWID who did not receive oral antibiotic therapy on AMA discharge (n = 46, 68.7%), compared with inpatient IV (n = 43, 31.5%) and partial oral (n = 27, 32.5%) antibiotics. In a multivariate analysis, 90-day readmission risk was higher among PWID who did not receive oral antibiotic therapy on AMA discharge (adjusted hazard ratio [aHR], 2.32; 95% confidence interval [CI], 1.41–3.82) and not different among PWID prescribed oral antibiotic therapy on AMA discharge (aHR, .99; 95% CI, .62–1.62). Surgical source control (aHR, .57; 95% CI, .37–.87) and addiction medicine consultation (aHR, .57; 95% CI, .38–.86) were both associated with reduced readmissions. Conclusions. Our single-center study suggests access to oral antibiotic therapy for PWID who cannot complete prolonged inpatient IV antibiotic courses is beneficial.