[Amikacin concentration in the severely obstructed urinary tract].

Urinary amikacin concentration was determined in 9 patients with severely unilateral ureteral obstruction. Serum levels were within the normal range. The average concentration of amikacin in the urine from obstructed urinary tract was 118.9 mcg/ml 6 hours after 100 mg amikacin iv infusion. Urine concentration from the normal kidney was 155.9 mcg/ml at the first 2 hours after intravenous infusion, 98.8 at the second 2 hours 83.3 at the third 2 hours. Urinary amikacin excretion from severely obstructed urinary tract was about one third of the total excretion from a normal system. In summary, the urinary level in severely obstructed urinary tract after iv infusion of 100 mg amikacin may be enough prophylactically. But at the onset of infection in severely obstructed urinary tract, the administration of at least 200 mg amikacin intravenously is required.