Phosphonic acid derivative
Gram-positive: Staphylococcus spp., Enterococcus spp.
Gram-negative: E. coli, Enterobacter spp., Citrobacter spp., Klebsiella spp., Proteus spp., Providencia spp. P. aeruginosa
Irreversibly attaches to pyruvyl transferase, an important enzyme in the early step of bacterial cell wall synthesis
Pharmacodynamics:
No data
Cmax: 26.2±8.1mcg/ml; Half-life: 3.6±0.44 (hr); Tmax: 2.5±0.8 (hr); Table 2
GI: diarrhea, nausea, abdominal pain
Other: vaginitis, headache, dizziness
PO: Powder for reconstitution
UTI in children < 5 years old: 2g once
UTI in Adults: 3g once
Disease state based dosing:
Renal failure: Dosing adjustments not necessary
Hepatic failure: Dosing adjustments not necessary
Contraindications/Warnings/Precautions:
Precautions: Food delays absorption – administer on an empty stomach
Cisapride: decreased urinary concentrations of fosfomycin
Metoclopromide: decreased urinary concentrations of fosfomycin
Pregnancy:
Category B: No evidence of risk in humans but studies inadequate.
Monitoring Requirements:
Therapeutic: Culture and sensitivities, signs and symptoms of infection
Toxic: None