Xu D et al. (2007) Dysfunctional voiding confirmed by transdermal perineal electromyography, and its effective treatment with baclofen in women with lower urinary tract symptoms: a randomized double-blind placebo-controlled crossover trial. BJU Int 100: 588–592

Dysfunctional voiding is a major cause of lower urinary tract symptoms in women for which there is no established, effective treatment. Xu and colleagues, therefore, conducted a randomized, double-blind, placebo-controlled crossover study to evaluate the efficacy of baclofen, a potent γ-aminobutyric acid receptor agonist, as a treatment for adult women with dysfunctional voiding.

The authors enrolled 60 women (mean age 46.2 years) who presented with urodynamically confirmed dysfunctional voiding and in whom >1 year's treatment with anticholinergic agents had failed. Following a placebo lead-in period, patients were randomly assigned to receive either oral baclofen (10 mg three times daily) or matching placebo for 4 weeks; after a washout period of 2 weeks, the groups then switched to the other treatment for a further 4 weeks. Improvement in symptoms was assessed with voiding diaries, multichannel urodynamics and electromyography, performed at baseline, 4 weeks and 10 weeks.

Patients experienced significantly fewer voids per 24 h period after receiving baclofen compared with placebo (mean difference from baseline 5.53 versus 2.70, P = 0.001). The TL value (logarithm of the electrical potential ratio of the sphincter before voiding and at maximum urinary flow rate) was also significantly higher in patients treated with baclofen compared with placebo (mean difference from baseline −1.78 versus 0.01, P = 0.001). There was no difference in adverse events related to baclofen and placebo.

The authors conclude that this proof-of-concept study shows 4 weeks of baclofen treatment is effective in women with dysfunctional voiding.