indication

For the treatment of uncomplicated urinary tract infections (acute cystitis) in women due to susceptible strains of Escherichia coli and Enterococcus faecalis.

pharmacology

Fosfomycin is a broad spectrum antibiotic that concentrates in kidney and bladder and is used to treat uncomplicated urinary tract infections. Fosfomycin also reduces nephrotoxicity and ototoxicity of platinum-containing anti-tumor agents.

mechanism of action

Fosfomycin is a phosphoenolpyruvate analogue produced by Streptomyces that irreversibly inhibits enolpyruvate transferase (MurA), which prevents the formation of N-acetylmuramic acid, an essential element of the peptidoglycan cell wall.

toxicity

LD₅₀>5 g/kg (rats). Side effects may include diarrhea

biotransformation

No transformation, excreted unchanged

absorption

Fosfomycin tromethamine is rapidly absorbed following oral administration and converted to fosfomycin. Oral bioavailability under fasting conditions is 37%. When given with food, oral bioavailability is reduced to 30%

half life

5.7 (± 2.8) hours. The elimination half-life is 40 hours in anuric patients undergoing hemodialysis.

route of elimination

Fosfomycin is excreted unchanged in both urine and feces.