KEY POINTS
- Fosfomycin (Monurol, Fomicyt) works against susceptible bacteria by inactivating pyruvyl transferase (an enzyme critical for cell wall synthesis), which results in interference with bacterial cell wall formation
- Fosfomycin has activity versus a wide variety of bacteria, including MRSA, Pseudomonas aeruginosa, Acinetobacter baumannii, E. coli, Klebsiella pneumoniae
- Has activity versus some carbapenemase and extended spectrum beta-lactamase producing organisms
- In the U.S. fosfomycin is only available as an oral packet, which is mixed with cool water before ingestion
- Fosfomycin is available as an injectable formulation outside of the U.S.
- Oral fosfomycin is only FDA-approved for uncomplicated UTI
- For uncomplicated UTI can give just one dose for treatment
- Oral fosfomycin has been used off-label for complicated UTI and prostatitis
- For off-label uses, the dosing interval is usually once every 48 or 72 hours
- Is not usually tested routinely by microbiology labs, so a request for testing may be needed
- Oral fosfomycin is somewhat expensive compared to other UTI agents
RESOURCES
- Oral fosfomycin Package Insert
- IDSA Practice Guidelines
- Fosfomycin Review Article (2016)
- FDA Expanded Access (Compassionate Use)