Long-term intermittent netilmicin therapy of chronic pyelonephritis: a pharmacokinetic and clinical study

A trial was conducted with long-term intermittent netilmicin therapy in six patients suffering from chronic pyelonephritis. Netilmicin was given in full dose for a period of 3-10 days (2-6 mg/kg/day), followed by 2 mg/kg doses once or twice weekly for 3-6 months. Individual doses were determined by computer based on the age, sex, lean body weight and serum creatinine concentrations of the patients. During the full-dose period of treatment netilmicin concentrations in serum were between 2 and 16 mg/l in serum and between 50 and 200 mg/l in urine. During intermittent treatment serum levels remained below 2 mg/l (except for 8-12 hours after dosing); in the urine concentrations were permanently in therapeutic ranges (150-4 mg/l). Renal tissue levels were simulated. Six to 12 months after long-term netilmicin treatment all patients are abacteriuric and free from symptoms. No auditory or renal toxic effects occurred.