Norfloxacin versus co-trimoxazole in the treatment of acute bacterial diarrhoea: a placebo controlled study.

The bacteriological and clinical efficacy of norfloxacin 400 mg b.i.d. was compared to those of co-trimoxazole (160 mg of trimethoprim plus 800 mg of sulphamethoxazole) b.i.d. and placebo b.i.d. for the treatment of acute bacterial diarrhoea in a randomized double-blind trial. Of a total of 450 patients with acute diarrhoea, 303 had positive bacterial cultures and were evaluable for efficacy. The time to elimination of pathogens was significantly (p less than 0.001) shorter in the norfloxacin group than in the co-trimoxazole and placebo groups. At completion of treatment, bacteriological cure was found in 97.9%, 72.4% and 38.2% of patients treated with norfloxacin, co-trimoxazole and placebo, respectively. All pathogens were susceptible to norfloxacin and none of them developed resistance to norfloxacin during treatment. In the co-trimoxazole group, resistance to that antibiotic increased from 2% at inclusion to 65.6% at the end of treatment (p less than 0.001). In patients with shigellosis or cholera, the mean time to normalization of bowel movements was significantly shorter in the norfloxacin and co-trimoxazole groups than in the placebo group (p less than 0.05 and p less than 0.01, respectively). There were no significant differences between groups with respect to adverse events reported. In conclusion, norfloxacin was well tolerated and highly effective in the treatment of acute bacterial diarrhoea.