Therapy for acute cystitis in adult women. Randomized comparison of single-dose sulfisoxazole vs trimethoprim-sulfamethoxazole.

One hundred seventeen unselected women with symptoms of acute cystitis were randomized to groups for immediate therapy with one of the following four single-dose regimens: (1) 1 g of sulfisoxazole; (2) 2 g of sulfisoxazole; (3) a combination of trimethoprim, 160 mg, and sulfamethoxazole, 800 mg; and (4) a combination of trimethoprim, 320 mg, and sulfamethoxazole, 1,600 mg. Forty-one women were excluded, 13 did not return for follow-up, and 28 did not have significant bacteriuria in the pretherapy culture. Escherichia coli was isolated in 81% of infections. Antibacterial activity was significantly greater in urine collected during the 24 hours after therapy in those who received trimethoprim-sulfamethoxazole. However, overall cure varied from 85% to 95%, without any great differences between the regimens. The rate of cure of 69% in the 13 patients with presumptive evidence of renal infection (antibody-coated bacteria present) was significantly lower than the rate of cure of 95% in women without evidence of renal infection. Single-dose therapy with these regimens was safe and effective in adult women with symptoms of acute cystitis, regardless of the localization of the site of infection.