Norfloxacin for selective decontamination: a study in human volunteers.

During five consecutive days three different dosages of 200, 400 and 800 mg norfloxacin were administered to ten healthy males. Cultures of feces and oral washings revealed that even the lowest dose was effective in eliminating gram-negative bacilli from the gi-tract within a reasonable period of time. At this dose signs of a decreased CR due to norfloxacin and measured by both overgrowth by resistant ppmo or the appearance of beta-asp-gly in feces were not seen. Treatment with 100 mg norfloxacin twice daily seems therefore suitable for SDD, at least in volunteers. However, further studies in patients should be performed.