Oxybutynin is preferred to tolterodine for overactive bladder

Question Is extended release oxybutynin or tolterodine more effective and tolerable in women with an overactive bladder?

Synopsis Overactive bladder is characterised by symptoms of urinary urgency, and frequent micturitions with or without involuntary loss of urine (urge incontinence). This randomised controlled (double blinded) study, conducted in 71 centres in the United States, enrolled 790 older women with 21 to 60 urge urinary incontinence episodes per week and who urinated 10 or more times per day. Almost half the women had previously been treated with an anticholinergic. The study did not include a placebo control arm and allocation concealment was not documented. The women randomly received extended release oxybutynin (Ditropan XL) 10 mg per day or extended release tolterodine (Detrol LA) 4 mg per day for three months. The women kept 24 hour diaries for seven days at baseline and during weeks 2, 4, 8, and 12 of treatment. The average number of weekly urinary urge incontinence episodes was not different between the two groups, decreasing from approximately 37 to 11 per week in each group. There was also no difference in the decrease of average number of total incontinence episodes between the two groups, dropping from approximately 43 to 13 per week. More women treated with oxybutynin reported no incontinence episodes in their last week of treatment (23% v 17%; number needed to treat = 16). Dry mouth was reported by 30% of women receiving oxybutynin and 22% of those receiving tolterodine, though most episodes were characterised as mild.

Bottom line After three months of treatment, approximately 1 in 4 women receiving extended-release oxybutynin and 1 in 6 women receiving extended-release tolterodine will be completely continent. Overall, both drugs similarly decreased the number of episodes of urge incontinence and total incontinence. Oxybutynin caused more reports of dry mouth. These results are similar to those seen with immediate release forms of both drugs.

Level of evidence 1c (see www.infopoems.com/resources/levels.html); all or none randomised controlled trials