Effectiveness of anticholinergic drugs for treating people with overactive bladder syndrome

Review question

We wanted to see whether a group of drugs, called anticholinergics, made a difference to adults who had an overactive bladder (OAB) syndrome when compared to a placebo (fake) treatment. We collected and analysed all relevant studies to answer this question.


Overactive bladder syndrome is a common problem, especially as people get older. It means that you may suddenly feel the need to go to the toilet (called an 'urgency episode'), or suddenly leak a bit of urine. Overactive bladder is caused by your bladder muscle losing control unexpectedly. It is sometimes called 'irritable bladder', 'detrusor overactivity', 'urge incontinence' or 'urgency-frequency syndrome'.

Anticholinergic drugs are often given to people who have overactive bladder. They work by relaxing the muscles and can help some of the symptoms of overactive bladder, such as leakage or needing to go to the toilet at short notice.

How up-to-date is this review?

We studied evidence that was available up until 14 January 2020.  We updated this search on 3 May 2022, but these results have not yet been fully incorporated into the review.

Study characteristics

We included 104 studies in this review. Seventy-one of these were new or had been updated since the last time this review was published in 2006.

Twelve of these studies did not report how many people were included in their research. In total across the rest of the studies, 29,682 people were given an anticholinergic drug compared to 17,424 people who were given a placebo. The smallest study was made up of 18 people while the largest had 2334 participants. Most of the studies we included in the review lasted for 12 weeks. One study investigated symptoms only in men, while nine looked at symptoms in women. The rest of the studies included both men and women.

We only included studies that used anticholinergic drugs taken by mouth, and only at dosages that doctors normally prescribe to patients. Across the studies, nine different anticholinergic drugs were included: darifenacin; fesoterodine; imidafenacin; oxybutynin; propantheline; propiverine; solifenacin; tolterodine and trospium.

Study funding sources

Seventy studies included in this review were funded by the companies that make and sell the drugs.

Key results

We found that people who take an anticholinergic drug for overactive bladder may feel a positive change in their quality of life. Also, our results show that more patients will probably perceive an improvement or cure of their symptoms of overactive bladder when compared to those who take the placebo treatment.

Taking an anticholinergic drug probably results in a small reduction in the number of urgency episodes and the number of times people with overactive bladder go to the toilet in one day.

Twenty-two people in every 100 given an anticholinergic drug felt they had a dry mouth as a side effect of the drug, compared to 6 in 100 taking placebo. Taking anticholinergics may therefore increase the risk of having a dry mouth. Anticholinergics may also result in an increased risk of urinary retention: fewer than 2 in every 100 people felt they were unable to completely empty their bladder after taking an anticholinergic drug in comparison to fewer than 0.5 in every 100 people after taking placebo. 

Authors’ conclusions

We found that anticholinergic drugs could result in small but important changes to a person’s quality of life and their overactive bladder symptoms, however it is unclear if these changes can be sustained over a long period of time. 

Authors' conclusions: 

The use of anticholinergic drugs by people with overactive bladder syndrome results in important but modest improvements in symptoms compared with placebo treatment. In addition, recent studies suggest that this is generally associated with only modest improvement in quality of life. Adverse effects were higher with all anticholinergics compared with placebo. Withdrawals due to adverse effects were also higher for all anticholinergics except tolterodine. It is not known whether any benefits of anticholinergics are sustained during long-term treatment or after treatment stops.

Read the full abstract...

Around 16% of adults have symptoms of overactive bladder (OAB; urgency with frequency and/or urge incontinence), with prevalence increasing with age. Anticholinergic drugs are commonly used to treat this condition.

This is an update of a Cochrane Review first published in 2002 and last updated in 2006.


To assess the effects of anticholinergic drugs compared with placebo or no treatment for treating overactive bladder syndrome in adults.

Search strategy: 

We searched the Cochrane Incontinence Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, ClinicalTrials.gov, WHO ICTRP and handsearching of journals and conference proceedings (searched 14 January 2020), and the reference lists of relevant articles. We updated this search on 3 May 2022, but these results have not yet been fully incorporated.

Selection criteria: 

We included randomised or quasi-randomised trials in adults with overactive bladder syndrome that compared an anticholinergic drug alone with placebo treatment.

Data collection and analysis: 

Two review authors independently assessed eligibility and extracted data from the included studies, including an assessment of the risk of bias. We assessed the certainty of the body of evidence using the GRADE approach. We processed data as described in the Cochrane Handbook for Systematic Reviews of Interventions.

Main results: 

We included 104 studies, 71 of which were new or updated for this version of the review. Although 12 studies did not report the number of participants, there were 47,106 people in the remainder of the included studies. The majority of the studies had insufficient information to allow judgement of risk of bias and we judged them to be unclear for all domains. Nine anticholinergic drugs were included in these studies: darifenacin; fesoterodine; imidafenacin; oxybutynin; propantheline; propiverine; solifenacin; tolterodine and trospium. No studies were found that compared anticholinergic drugs to no treatment.

At the end of the treatment period, anticholinergics may slightly increase condition-specific quality of life (mean difference (MD) 4.41 lower, 95% confidence interval (CI) 5.28 lower to 3.54 lower (scale range -100 to 0); 12 studies, 6804 participants; low-certainty evidence). Anticholinergics are probably better than placebo in terms of patient perception of cure or improvement (risk ratio (RR) 1.38, 95% CI 1.15 to 1.66; 9 studies, 8457 participants; moderate-certainty evidence), and the mean number of urgency episodes per 24-hour period (MD 0.85 lower, 95% CI 1.03 lower to 0.67 lower; 23 studies, 16,875 participants; moderate-certainty evidence).

Compared to placebo, anticholinergics may result in an increase in dry mouth adverse events (RR 3.50, 95% CI 3.26 to 3.75; 66 studies, 38,368 participants; low-certainty evidence), and may result in an increased risk of urinary retention (RR 3.52, 95% CI 2.04 to 6.08; 17 studies, 7862 participants; low-certainty evidence). Taking anticholinergics may be more likely to lead to participants withdrawing from the studies due to adverse events (RR 1.37, 95% CI 1.21 to 1.56; 61 studies, 36,943 participants; low-certainty evidence). However, taking anticholinergics probably reduces the mean number of micturitions per 24-hour period compared to placebo (MD 0.85 lower, 95% CI 0.98 lower to 0.73 lower; 30 studies, 19,395 participants; moderate-certainty evidence).