Urinary concentrations of fosfomycin after a single 3 g dose of fosfomycin to elderly nursing-home patients.

The urinary concentrations of fosfomycin in 7 elderly patients with impaired renal function (mean creatinine clearance 40 ml/min) were studied after a single oral dose of 3 g fosfomycin as the trometamol salt. Urine samples were collected as 12 h portions for 84 h. Urinary concentrations of fosfomycin were 1,383 mg/l (range 314 to 4,200 mg/l) in the first 12 h and gradually declined to 165 mg/l (range 65 to 365 mg/l) between 36 and 48 h.