A double-blind comparative study of norfloxacin versus placebo in hospitalised elderly patients with asymptomatic...

Patients over the age of 65 years with clear catch specimens of urine containing organisms sensitive to norfloxacin were blindly randomised to receive either norfloxacin in a dose of 400 mg twice daily for 7 days or a placebo for the same period. Urine cultures were repeated immediately prior to treatment, at the end of treatment and at 7 days, 1 month and 3 months after treatment. Physical and mental function were assessed by performing a Crighton Behavioural Rating Scale at the same time intervals. Observations were made on 29 each of subjects on norfloxacin and placebo. The proportions of patients abacteriuric at the end of treatment, 7 days and 3 months post- treatment were 16/24 (66%), 12/24 (50%) and 5/24 (21%) in the norfloxacin group and 10/26 (38%), 8/26 (31%) and 8/25 (32%) in the placebo group. Percentage calculations (and denominators) exclude those patients withdrawn or for whom there were no specimens available at the sampling interval in question. Means and 95% intervals for the Crighton Behaviour Rating Scales initially and at 3 months in subjects on norfloxacin were 18.1 (15.1-20.7) and 19.1 (16.2-21.9) respectively. The same figures for the placebo group were 15.7 (12.6-18.8) and 16.6 (13.7-19.5). It is concluded that a 7 day course of norfloxacin for the treatment of asymptomatic bacteriuria had no effect on the physical and mental function of elderly continuing care patients, and that one explanation for this is that there was a high rate of urinary re-infection.