Effect of antibiotics on urine leakage in women with refractory detrusor overactivity: a phase IIb randomized trial

Aim: Because bacterial cystitis is common in women with refractory detrusor overactivity, the aim was to compare the efficacy of 6 weeks of rotating antibiotics versus placebo, in conjunction with an anticholinergic, in controlling the symptoms of urge incontinence.

Methods: In a multicenter phase IIb double-blinded randomized placebo-controlled trial, women with urodynamically proven refractory detrusor overactivity were randomized in a 2:1 ratio of antibiotics versus placebo for 6 weeks, in addition to darifenacin for 6 months. Any woman with disabling cystitis symptoms was given appropriate antibiotics (“clinical override”). The primary outcome was the degree of urge incontinence change at 6 weeks and 6 months on 24-h pad test. Secondary outcomes were changes in leaks and voids per day measured on 3-day bladder diary and quality of life measures. Microbiological data were collected at all visits.

Results: Although 278 women were screened, only 36 were randomized and 33 (91.7%) completed the trial. Leakage on 24-h pad test decreased at 6 months by 75 g in patients receiving antibiotics versus 35 g in placebo. Cure of urge incontinence occurred at 6 months in 10/21 (48%) of antibiotics versus 2/12 (17%) of placebo. Clinical override, necessitating treatment of cystitis, occurred in 41.6% of placebo versus 16.7% of the antibiotic group by 6 months.

Conclusion: Despite the small sample size, the study showed a significant reduction in pad leakage and leaks per day over 24 h in the active treatment group over a 6-month period. Nearly half of patients on placebo had disabling urinary tract infection symptoms that required clinical override treatment.