Clinical Question: Is three days of ciprofloxacin therapy as effective as seven to 10 days of the same drug in older women with urinary tract infection (UTI)?

Setting: Outpatient (any)

Study Design: Randomized controlled trial (double-blinded)

Synopsis: In this study, women older than 65 years with a positive urine culture and at least one symptom of UTI were randomized to receive oral ciprofloxacin in a dosage of 250 mg twice daily for three days plus placebo for four days (n = 93) or ciprofloxacin in a dosage of 250 mg twice daily for seven days (n = 89). Women with diabetes, an indwelling catheter, abnormal renal function, sepsis, recent use of antibiotics, or signs of pyelonephritis (not specified) were excluded. The groups were similar at base-line, allocation was appropriately concealed, and analysis was by intention to treat.

Patients were followed for a total of six weeks. Four patients withdrew from the seven-day group because of adverse events, compared with one patient in the three-day group. Two deaths occurred in each group (the study included some hospitalized patients because it was organized through a central laboratory).

Most patients (71 percent) had Escherichia coli, and 15.8 percent had Klebsiella pneumoniae. No differences between groups were noted two days after completion of antibiotic therapy regarding bacterial eradication (98 percent for the three-day group versus 93 percent for the seven-day group) or symptom improvement (98 percent for the three-day group versus 92 percent for the seven-day group). The same was true at six weeks, with similar rates of reinfection (14 percent for the three-day group versus 18 percent for the seven-day group) and relapse (15 percent versus 13 percent). Adverse effects—drowsiness, loss of appetite, and nausea or vomiting, in particular—were more common among patients in the seven-day group.

Bottom Line: This reasonably large study found that treatment with three days of ciprofloxacin twice daily is as effective and better tolerated than seven days of treatment in healthy older women with UTI. Although a much larger study might find a small difference in outcomes, it is unlikely to be clinically meaningful; this study was powered to detect a modest 10 percent difference in outcomes. (Level of Evidence: 1b)