Overview
Fosfomycin is a broad-spectrum bactericidal antibiotic that inhibits bacterial cell wall synthesis by inactivating the enzyme UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), which is essential for peptidoglycan formation. It is primarily used for uncomplicated urinary tract infections (UTIs) caused by susceptible bacteria, including Escherichia coli and Enterococcus faecalis. Fosfomycin tromethamine is available as an oral single-dose treatment, offering convenience and high urinary concentrations.
Mechanism of Action
Fosfomycin irreversibly inhibits the enzyme UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), which catalyzes the first step in peptidoglycan biosynthesis. This inhibition prevents the formation of N-acetylmuramic acid, a critical component of the bacterial cell wall, leading to bactericidal activity against susceptible organisms.
Indications
- Uncomplicated urinary tract infections (UTIs) in women caused by susceptible strains of Escherichia coli and Enterococcus faecalis
Dosage
For uncomplicated UTIs: A single 3-gram sachet of fosfomycin tromethamine dissolved in water and taken orally. It should be administered on an empty stomach (at least 2 hours before or after a meal) to maximize absorption.
Contraindications
- Hypersensitivity to fosfomycin or any component of the formulation
Side Effects
- Diarrhea
- Nausea
- Headache
- Vaginitis
- Dizziness
- Dyspepsia
- Abdominal pain
- Back pain
- Rash
Interactions
- Metoclopramide may decrease fosfomycin absorption; avoid concurrent use
- Antacids containing aluminum or magnesium may reduce fosfomycin absorption; administer fosfomycin at least 2 hours before or after antacids