Cefazolin is a recommended treatment for methicillin-susceptible Staphylococcus aureus
(MSSA) infections that has been successfully used in outpatient parenteral antibiotic therapy (OPAT)
programs. The aim of this study was to assess the clinical outcomes of cefazolin delivered each day
(Group 24) vs. every two days (Group 48) for MSSA infections in OPAT programs. It was a prospective
observational study with retrospective analysis of a cohort of MSSA infections attended in OPAT. The
primary outcome was treatment success, defined as completing the antimicrobial regimen without
death, treatment discontinuation, or readmission during treatment and follow-up. A univariate and
multivariate logistic regression model was built. A two-sided p < 0.05 was considered statistically
significant. Of the 149 MSSA infections treated with cefazolin 2 g/8 h in OPATs, 94 and 55 patients
were included in the delivery Group 24 and Group 48, respectively. Treatment failure and unplanned
readmission rates were similar in both groups (11.7% vs. 7.3% p = 0.752 and 8.5% vs. 5.5% p = 0.491).
There was a significant increase in vascular access complications in Group 24 (33.0%) with respect to
Group 48 (7.3%) (p < 0.001). Treating uncomplicated MSSA infection with cefazolin home-delivered
every two days through an OPAT program is not associated with an increased risk of treatment
failure and entails a significant reduction in resource consumption compared to daily delivery