Norfloxacin 800 mg or norfloxacin 1600 mg (at or twice the recommended daily dose, respectively) while participating in a double blind, crossover study comparing single doses of norfloxacin with placebo While crystalluria is not expected to occur under usual conditions with a dosage regimen of 400 mg twice daily,Prophylaxis with norfloxacin 400 mg orally daily decreases inhospital incidence of SBP from 22% to 0% without an effect on inhospital mortality 4 Trimethoprimsulfamethoxazole, one doublestrength tablet orally daily, has also been reported to be effective in preventing SBP and has supplanted norfloxacin in the United StatesThe typical adult dose of Norfloxacin is 400 mg twice a day (not more than 800 mg daily) The maximum dose for adults of Norfloxacin is 800 mg once daily per day This medicine is commonly used for a period of 310 days for uncomplicated urinary tract infection, 1021 days for complicated urinary tract infection, 1 day for uncomplicated gonorrhea, and 28 days for