Intravenous fosfomycin indications and treatment outcomes in pediatric usage: analysis from a single center in Turkey

Current data on fosfomycin usage in children are limited. We present data on the clinical use of intravenous (IV) fosfomycin in children. Hospitalized patients who received ≥3 days of IV fosfomycin between April 2021 and March 2023 were analyzed retrospectively. Forty-three episodes of infection in 39 patients were evaluated. The mean age of the patients was 5.35 (10 days to 17.5 years) years, and 54% were male. Infections were hospital-acquired in 79% of the episodes. Indications for fosfomycin were urinary tract infection (35%), bacteremia (32.6%), catheter-related bloodstream infection (16.3%), soft tissue infection (4.7%), sepsis (4.7%), surgical site infection (2.3%), burn infection (2.3%), and pneumonia (2.3%). Klebsiella pneumoniae was identified in 46.5% of the episodes, and a pan-drug or extensive drug resistance was detected in 75% of them. Carbapenem was used before fosfomycin at significantly higher rates in K. pneumoniae episodes (P = .006). Most (88.5%) patients received fosfomycin as a combination therapy. Culture negativity was achieved in 80% of episodes within a median treatment period of 3 (2-22) days, which was significantly shorter in K. pneumoniae episodes (P < .001). Treatment-related side effects were seen in 9.3% of the episodes. Side effects were significant after 3 weeks of treatment (P = .013). The unresponsivity rate to fosfomycin was 23.3%. Nine (21%) of the patients who were followed up in the intensive care units mainly died because of sepsis (56%). IV fosfomycin is an effective agent in treating severe pediatric infections caused by resistant microorganisms. Fosfomycin can be used in various indications and is generally safe for children.