Cefadroxil as Oral Transitional Therapy for Gram-Positive Bacteremia With or Without Non-Vertebral Osteomyelitis: A Multicenter Retrospective Cohort Study.

BACKGROUND

Oral cefadroxil has favorable pharmacokinetics for the treatment of bloodstream infection (BSI) and osteomyelitis caused by Gram-positive cocci (GPC), but limited clinical data exist.

METHODS

We conducted a multicenter, retrospective cohort study between September 2022 and April 2025 assessing cefadroxil versus intravenous (IV)-only or other oral transitional therapy in adults with susceptible GPC BSI, with or without osteomyelitis. No patients with endocarditis, vertebral osteomyelitis, or prosthetic or central nervous system infections were included. Primary outcome was treatment success, defined as 90-day survival without infection progression or relapse. Prioritized secondary outcomes included all-cause mortality, recurrent bacteremia, and readmission at 90 days.

RESULTS

Of 323 patients with BSI, 58 were treated with cefadroxil, 72 IV only, and 193 with other oral antibiotics. Rates of osteomyelitis were comparable in each cohort, but skin and soft-tissue infections were a more common source of bacteremia in cefadroxil (52%) than either IV (28%, P = .01) or orally (PO) (31%, P = .003) cohorts. Staphylococcus aureus was more frequent in the IV (60%) than cefadroxil cohort (36%, P = .008). Nevertheless, cefadroxil-treated patients had a similar case mix index, expected mortality, and expected length of stay as the IV and PO cohorts, indicating comparable populations. Treatment success was similar for cefadroxil (91%), IV (94%, P = .51), and other oral (93%, P = .63) cohorts. Mortality, hospital readmission, and adverse events were comparable between groups.

CONCLUSIONS

We found similar outcomes for cefadroxil and IV or PO alternatives in patients with GPC BSI, absent endocarditis, vertebral osteomyelitis, prosthetic or central nervous system infection. Cefadroxil was well-tolerated without observed severe adverse events.

MAIN POINT: In this multicenter, retrospective cohort study, cefadroxil was an effective and safe oral transitional therapy for bloodstream infections, with or without nonvertebral osteomyelitis.