Trimethoprim-sulfamethoxazole compared to ampicillin in the treatment of shigellosis.

Twenty hospitalized children between 1 and 11 years of age were enrolled in a comparative randomized evaluation of trimethoprim-sulfamethoxazole (TM-SM) and ampicillin for the treatment of shigellosis. Each drug was provided for five days. The group treated with ampicillin had significantly more stools per day (mean 21.25) compared to the TM-SM group (8.64). Treatment with TM-SM appeared to be associated with a more rapid reversion of stool cultures to normal, but these differences compared to ampicillin were not statistically significant. Review of all isolates of Shigella from our hospital revealed a marked decrease in sensitivity to ampicillin over the last six years. This pattern has been observed in other centers. TM-SM may be the best drug for the treatment of shigellosis in areas where multiple antibiotic-resistant organisms are common.