Urinary tract infections in patients with severe renal disease. Treatment with ampicillin and trimethoprim-sulfamethoxazole.

Twelve patients with severe renal failure and intercurrent urinary tract infections were treated with either ampicillin trihydrate, 500 mg four times a day, or trimethoprim-sulfamethoxazole, two tablets (80 mg trimethoprim, 400 mg sulfamethoxazole) twice a day. All patients achieved bacteriologic cure, including six with proved upper tract infection. Serum levels of all drugs were increased to values above those seen in normal subjects without adverse effects. Urine concentrations of trimethoprim, 28.6 mug/ml, and ampicillin, 88.6 mug/ml, were well above the minimum inhibitory concentrations of urinary pathogens. Urine sulfamethoxazole concentrations were less than 10 mug/ml in four of the six patients treated; however, this did not hamper bacteriologic success. It is concluded that both drugs can be used to treat urinary tract infections in patients with renal functional impairment.