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

F. J. Buckwold, P. Ludwig, G. K. Harding, L. Thompson, M. Slutchuk, J. Shaw and A. R. Ronald

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.