Treatment with single doses of antibiotics of uncomplicated urinary tract infections in women is a well-established therapeutic regimen (1,4,12,15,20). Therapeutic failures following a single-dose treatment appear to predict complicating factors such as silent pyelonephritis (14), morphologic alterations, dynamic disturbances, or microbial resistance to antibiotics (6,8,11,13).Ciprofloxacin, a new'quinolone drug which can be administered both orally and intravenously, has good antimicrobial activity against microorganisms frequently found in urinary tract infections. The aim of the present study was to evaluate the efficacy of a single dose of ciprofloxacin in the treatment of uncomplicated'urinary tract infection. In addition, two oral doses, 250 and 100 mg, were compared to estimate clinical and bacteriological efficacy at the lower-dosage range.Women 16 years or older attending our outpatient clinic were enrolled in the study if they presented with acute dysuria and frequent micturition of <72 h in' duration. Admission criteria included bacteriuria (>102 CFPU/ml) and pyuria (>10 leukocytes per mm3). Exclusion criteria were pregnancy, fever of >38°C, serum creatinine of >115 pumol/liter, and a history of antecedent complicated urinary tract infection (e.g., due to obstruction in the u4nary tract).Uncomplicated recurrent urinary tract infections did not lead to exclusion. A total blood count, erythrocyte sedimentation rate, serum creatinine, alkaline phosphatase, and glutamate pyruvate transaminase were determined at presentation.Midstream urine was collected after individual instruction of the patient and was cultivated quantitatively on human blood and MacConkey agar plates. Uropathogenic microorganisms were differentiated according to standard methods, and Staphylococcus saprophyticus was identified by the novobiocin method (5). A routine sensitivity test by photometric measurement of the optical density (MS-2 automated antimicrobial susceptibility testing system; Abbott Laboratories, Chicago, Ill.), as well as determinations of MICs by a micromethod (16) in Mueller-Hinton broth and a disk test on Mueller-Hinton agar for ciprofloxacin, was performed for all isolates (2). Patients received either 100 or 250 mg of ciprofloxacin orally at presentation, before any laJoratory values were available.A total of 40 women with a median age of 25.0 years (range, 18 to 61 years) entered the study, 2 of whom had to be excluded because initial culture-s were inconclusive * Corresponding author.354
