Comparison of trimethoprim-sulfamethoxazole and ampicillin theraphy for shigellosis in ambulatory.

One-hundred seventy-four infants and children with acute diarrhea were treated as ambulatory patients with either ampicillin (100 mg/kg/day orally in four divided doses) or trimethoprim sulfamethoxazole (10 mg TMP and 50 mg SMX/KG/day orally in two divided doses). There were 65 patients with shigellosis. Responses of those treated with TMP/SMX and of those with susceptible Shigella treated with ampicillin were comparable. Patients with resistant organisms failed to respond to ampicillin. All Shigella, including ampicillin-resistant strains, were suseptible in vitro to TMP/SMX, and patients with ampicillin-resistant strains responded favorably to treatment with TMP/SMX. TMP/SMX appears to be the best, currently available drug for the treatment of shigellosis.