Three studies were undertaken to determine the minimum effective dosing regimen of ciprofloxacin for the treatment of acute, symptomatic, uncomplicated lower urinary tract infection.
All studies were multicenter, prospective, randomized, double-blind trials. A total of 970 evaluable patients with a diagnosis of urinary tract infection received oral ciprofloxacin (200 mg to 500 mg daily in one or two divided doses for 1, 3, 5, or 7 days) or norfloxacin (400 mg twice daily [BID] for 7 days). The primary measure of efficacy was bacteriologic eradication at the end of therapy.
In study 1, bacteriologic eradication was reported in 95 (89%) and 101 (98%) of patients in the groups who received ciprofloxacin, 500-mg single dose and 250 mg BID for 7 days, respectively. Clinical success occurred in 101 patients (94%) who received a 500-mg single dose and in 103 patients (100%) who were administered 250 mg BID for 7 days. In study 2, eradication rates in the groups who received ciprofloxacin, 100 mg BID for 3 days, 250 mg BID for 3 days, and 250 mg BID for 7 days, were 98 (93%), 95 (90%), and 98 (93%), respectively. Clinical success was reported in 102 (97%), 105 (100%), and 104 (98%) of the patients, respectively. In study 3, the eradication rates in the groups who received ciprofloxacin in dosages of 500 mg once daily for 3 days and 500 mg once daily for 5 days and norfloxacin in a dosage of 400 mg BID for 7 days were 137 (92%), 134 (90%), and 133 (94%) of the women, respectively. Clinical success was the same (97%) in all three groups. Overall, short-course (either 3- or 5-day) therapy with ciprofloxacin was statistically equivalent to conventional (7-day) therapy with either ciprofloxacin or norfloxacin. Single-dose ciprofloxacin therapy was statistically less effective than conventional treatment.
Ciprofloxacin at a dosage of 100 mg BID for 3 days was the minimum effective dose for the treatment of uncomplicated urinary tract infection in women.(Arch Intern Med. 1995;155:485-494)