Serum levels of mecillinam in patients with severely impaired renal function.

12 patients with severe renal insufficiency were treated for urinary tract infection with 400 mg of mecillinam intravenously every 6 h. High serum concentrations of mecillinam were found 6 h after the first morning dose on day 2 and day 5 of the treatment period (mean values 11.4 and 14.5 microgram/ml respectively), and a serum half-life of 334 min. In spite of reduced elimination of the drug, a nearly steady state was achieved within the first few days of treatment. Side effects were not observed.