Alpha-blockers ineffective in women with overactive bladder syndrome
Overactive bladder syndrome (OAB) is a common problem. Its symptom complex comprises urgency, frequency and nocturia. While in men treatment is often targeted at the most common cause, ie bladder outflow obstruction secondary to benign prostatic enlargement, in women treatment is usually with anticholinergics.
Studies suggest, however, that a combination of lack of efficacy and considerable side-effects (eg dry mouth) means that fewer than 50% of patients on these drugs continue treatment beyond one month (even on newer, extended release formulations).
With significant alpha-receptor activity in the bladder neck of women, it has been postulated that selective alpha-blockers may mediate symptoms of OAB in women and these drugs have been used off-label for this indication for some time.
A study has compared the use of tamsulosin, an alpha-blocker, with placebo in OAB and found no significant difference in reducing the number of voids.
The multicentre study included more than 360 women in 12 European countries. They were randomised to receive placebo, various strengths of extended release tamsulosin or extended release tolterodine. Treatment was for six weeks, with two weeks of follow-up. The primary outcome measure was change from baseline in mean number of voids per 24 hours.
There was no statistical difference between tamsulosin and placebo for the primary outcome, nor for various other secondary outcome measures, such as the number of episodes of urgency or incontinence.
Although this is a relatively small study, with only 60 patients in each arm, the findings suggest that alpha-blockers are ineffective for the management of symptoms of OAB in women and question their continued off-label use.
However, this study does not discount the use of alpha-blockers in combination with an anticholinergic, which remains to be studied.
Robinson D, Cardozo L, Terpstra G et al. A randomized double-blind placebo-controlled multicentre study to explore the efficacy and safety of tamsulosin and tolterodine in women with overactive bladder syndrome. BJU Int 2007;100:840-5Reviewer
Dr Jonathan Rees
GPwSI Urology, Bristol