Background
Fosfomycin is a potentially attractive option as step-down therapy for bacteraemic urinary tract infections (BUTI), but available data are scarce. Our
Conclusions
Fosfomycin trometamol might be a reasonable option as step-down therapy in patients with BUTI due to MDR-Ec but the higher rate of relapses would need further assessment.
Methods
Participants in the FOREST trial (comparing IV fosfomycin with ceftriaxone or meropenem for BUTI caused by MDR-Ec in 22 Spanish hospitals from June 2014 to December 2018) who were stepped-down to oral fosfomycin (3 g q48h) or other drugs were included. The primary endpoint was clinical and microbiological cure (CMC) 5-7 days after finalization of treatment. A multivariate analysis was performed using logistic regression to estimate the association of oral step-down with fosfomycin with CMC adjusted for confounders.
Results
Overall, 61 patients switched to oral fosfomycin trometamol and 47 to other drugs (cefuroxime axetil, 28; amoxicillin/clavulanic acid and trimethoprim/sulfamethoxazole, 7 each; ciprofloxacin, 5) were included. CMC was reached by 48/61 patients (78.7%) treated with fosfomycin trometamol and 38/47 (80.9%) with other drugs (difference, -2.2; 95% CI: -17.5 to 13.1; P = 0.38). Subgroup analyses provided similar results. Relapses occurred in 9/61 (15.0%) and 2/47 (4.3%) of patients, respectively (P = 0.03). The adjusted OR for CMC was 1.11 (95% CI: 0.42-3.29, P = 0.75). No relevant differences in adverse events were seen. Conclusions: Fosfomycin trometamol might be a reasonable option as step-down therapy in patients with BUTI due to MDR-Ec but the higher rate of relapses would need further assessment.