Comparison of orally absorbable andnonabsorbable antibiotics in shigellosis. A double-blind study with ampicillin and neomycin

The effects of orally administered neomycin and ampicillin on bacteriological cure and clinical course in acute shigellosis were assessed by a double-blind treatment study of 30 hospitalized infants and children. "Bacteeriological failure" (cultures positive more than 48 hours after initiation of therapy) occurred in 87 per cent of patients who received neomycin and in 13 per cent of those treated with ampicillin. All Shigellae showed in vitro susceptibility to the antibiotics used. "Clinical failure" (persistence of diarrhea beyond 5 days after starting therapy or removal of the patients from study or both) occurred in 60 per cent of the neomycin-treated group and in 13 per cent of those treated with ampicillin. Statistically significant differences between neomycin and ampicillin therapy were also demonstrated for the following parameteers: days until stool culture was negative, presence of Candida species in the stool, and days until afebrile. The failure of oral neomycin therapy in shigellosis supports the concept that nonabsorbable antimicrobial agents are not optimal therapy for acute shigellosis regardless of in vitro susceptibility.