Fosfomycin sodium

Objective: To assess pharmacokinetics and changes to sodium levels in addition to adverse events (AEs) associated with fosfomycin among neonates with clinical sepsis. Design: A single-centre open-label randomised controlled trial. Setting: Kilifi County Hospital, Kenya. Patients: 120 neonates aged ≤28 days admitted being treated with standard-of-care (SOC) antibiotics for sepsis: ampicillin and gentamicin between March 2018 and February 2019. Intervention: We randomly assigned half the participants to receive additional intravenous then oral fosfomycin at 100 mg/kg two times per day for up to 7 days (SOC-F) and followed up for 28 days. Main outcomes and measures: Serum sodium, AEs and fosfomycin pharmacokinetics. Results: 61 and 59 infants aged 0-23 days were assigned to SOC-F and SOC, respectively. There was no evidence of impact of fosfomycin on serum sodium or gastrointestinal side effects. We observed 35 AEs among 25 SOC-F participants and 50 AEs among 34 SOC participants during 1560 and 1565 infant-days observation, respectively (2.2 vs 3.2 events/100 infant-days; incidence rate difference -0.95 events/100 infant-days (95% CI -2.1 to 0.20)). Four SOC-F and 3 SOC participants died. From 238 pharmacokinetic samples, modelling suggests an intravenous dose of 150 mg/kg two times per day is required for pharmacodynamic target attainment in most children, reduced to 100 mg/kg two times per day in neonates aged <7 days or weighing <1500 g. Conclusion and relevance: Fosfomycin offers potential as an affordable regimen with a simple dosing schedule for neonatal sepsis. Further research on its safety is needed in larger cohorts of hospitalised neonates, including very preterm neonates or those critically ill. Resistance suppression would only be achieved for the most sensitive of organisms so fosfomycin is recommended to be used in combination with another antimicrobial. Trial registration number: NCT03453177.

Objectives: In March 2019, cefazolin was unavailable owing to difficulty in procuring the active ingredient. Furthermore, the supply of alternative drugs, such as cefotiam and cefmetazole, was limited. In the Department of Nephro-Urology, fosfomycin-based drugs are used as substitutes for cefazolin, which is a perioperative prophylactic antibacterial drug. Herein, we investigated the effectiveness of fosfomycin sodium and cefotiam in preventing infection after endoscopic combined intrarenal surgery as a retrospective preliminary study. Methods: A total of 200 patients who underwent endoscopic combined intrarenal surgery at our department between August 2017 and January 2021 were included. The patients were administered cefotiam (n = 95) or fosfomycin (n = 105) as perioperative antibacterial agents. There were no significant differences in the median age or surgery time between the cefotiam and fosfomycin groups. Propensity score matching was performed to match the preoperative urine bacterial counts of both groups. Sixty-eight patients were selected from each group. Results: The median postoperative hospital stay duration was 4 days for the two groups. The median maximum postoperative temperatures were 37.5 and 37.4°C, respectively. There were no significant differences between the maximum postoperative temperatures in both groups. Furthermore, there were no differences between the groups regarding the white blood cell counts, C-reactive protein levels, and aspartate aminotransferase and alanine aminotransferase levels postoperatively, as well as in terms of postoperative fever requiring additional antibiotics. Conclusions: During a period of difficulty in acquiring cefazolin and cefotiam, the use of fosfomycin allowed us to continue with the procedure without increased clinical complications.

The objectives of this study were to characterize the role of the uhpT, glpT, and fosA genes in fosfomycin resistance in Klebsiella pneumoniae and evaluate the use of sodium phosphonoformate (PPF) in combination with fosfomycin. Seven clinical isolates of K. pneumoniae and the reference strain (ATCC 700721) were used, and their genomes were sequenced. ΔuhpT, ΔglpT, and ΔfosA mutants were constructed from two isolates and K. pneumoniae ATCC 700721. Fosfomycin susceptibility testing was done by the gradient strip method. Synergy between fosfomycin and PPF was studied by checkerboard assay and analyzed using SynergyFinder. Spontaneous fosfomycin mutant frequencies at 64 and 512 mg/liter, in vitro activity using growth curves with fosfomycin gradient concentrations (0 to 256mg/liter), and time-kill assays at 64 and 307 mg/liter were evaluated with and without PPF (0.623 mM). The MICs of fosfomycin against the clinical isolates ranged from 16 to ≥1,024 mg/liter. The addition of 0.623 mM PPF reduced fosfomycin MIC between 2- and 8-fold. Deletion of fosA led to a 32-fold decrease. Synergistic activities were observed with the combination of fosfomycin and PPF (most synergistic area at 0.623 mM). The lowest fosfomycin-resistant mutant frequencies were found in ΔfosA mutants, with decreases in frequency from 1.69 × 10-1 to 1.60 × 10-5 for 64 mg/liter of fosfomycin. In the final growth monitoring and time-kill assays, fosfomycin showed a bactericidal effect only with the deletion of fosA and not with the addition of PPF. We conclude that fosA gene inactivation leads to a decrease in fosfomycin resistance in K. pneumoniae The pharmacological approach using PPF did not achieve enough activity, and the effect decreased with the presence of fosfomycin-resistant mutations.