Early Oral Switch to Linezolid for Low-risk Patients With Staphylococcus aureus Bloodstream Infections: A Propensity-matched Cohort Study

Background. Oral switch to linezolid is a promising alternative to standard parenteral therapy (SPT) in Staphylococcus aureus bacteremia (SAB). Methods. We conducted a prospective cohort study of all adult cases of SAB between 2013 and 2017 in a Spanish university hospital. We compared the efficacy, safety, and length of hospital stay of patients receiving SPT and those where SPT was switched to oral linezolid between days 3 and 9 of treatment until completion. We excluded complicated SAB and osteoarticular infections. A k-nearest neighbor algorithm was used for propensity score matching with a 2: 1 ratio. Results. After propensity score matching, we included 45 patients from the linezolid group and 90 patients from the SPT group. Leading SAB sources were catheter related (49.6%), unknown origin (20.0%), and skin and soft tissue (17.0%). We observed no difference in 90-day relapse between the linezolid group and the SPT group (2.2% vs 4.4% respectively; P = .87). No statistically significant difference was observed in 30-day all-cause mortality between the linezolid group and the SPT group (2.2% vs 13.3%; P = .08). The median length of hospital stay after onset was 8 days in the linezolid group and 19 days in the SPT group (P < .01). No drug-related events leading to discontinuation were noted in the linezolid group. Conclusions. Treatment of SAB in selected low-risk patients with an oral switch to linezolid between days 3 and 9 of treatment until completion yielded similar clinical outcomes as SPT, allowing earlier discharge from the hospital.