Background: Around 16% of adults have symptoms of overactive bladder (urgency with frequency and/or urge incontinence). The prevalence increases with age. Anticholinergic drugs are commonly used to treat this condition.
Objectives: To determine the effects of anticholinergic drugs for the treatment of overactive bladder syndrome.
Search strategy: The Cochrane Incontinence Group trials register was searched to January 2002.
Selection criteria: Randomised or quasi-randomised trials in adults with overactive bladder syndrome that compared an anticholinergic drug with placebo treatment or no treatment.
Data collection and analysis: Two reviewers independently assessed eligibility, trial quality and extracted data. Data were processed as described in the Cochrane Collaboration Handbook.
Main results: Fifty one trials, 32 parallel designs and 19 crossover designs were included (6713 adults). Most trials were described as double-blind, but were variable in other aspects of quality. The crossover trials did not present data in a way that allowed inclusion in the meta-analysis. Seven medications were tested: darifenacin; emepronium bromide or carrageenate; oxybutynin chloride; propiverine; propantheline; tolterodine; and trospium chloride. One trial included the newer, slow release, formulation of tolterodine. After treatment, cure/improvement (RR 1.41, 95%CI 1.29 to 1.54), changes in leakage episodes in 24 hours (WMD -0.56, 95%CI -0.73 to -0.39), number of voids in 24 hours (WMD -0.59, 95%CI -0.83 to -0.36), maximum cystometric volume (WMD 53.85 ml, 95%CI 42.28 to 65.41), and volume at first contraction (WMD 52.25 ml, 95%CI 37.45 to 67.06), were significantly in favour of medication. Medication was associated with significantly higher residual volumes (WMD 4.06 ml, 95%CI 0.73 to 7.39) and more than two and a half times the rate of dry mouth (RR 2.61, 95% CI 2.27 to 3.00). Sensitivity analysis, while limited by small numbers of trials, showed little likelihood that these effects were modified by age, sex, diagnosis, or choice of drug.
Reviewer's conclusions: The use of anticholinergic drugs by people with overactive bladder syndrome results in statistically significant improvement in symptoms. However, the clinical significance of these differences is uncertain, and the longer-term effects are not known. Dry mouth is a common side effect of therapy.