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

To assess the activity of baclofen, a potent gamma-aminobutyric acid-ergic agonist, against dysfunctional voiding (DV) and lower urinary tract symptoms (LUTS) in a clinical trial, as DV is a leading cause of LUTS in women, but there is no effective treatment. We conducted a randomized double-blind placebo-controlled crossover trial in 60 women with DV and LUTS between January 2003 and January 2006; patients were randomly assigned either baclofen 10 mg three times daily, then matching placebo for 4 weeks, or matching placebo then baclofen 10 mg three times daily for 4 weeks, separated by a 2-week washout period. Voiding diaries and multichannel urodynamics (at baseline, 4 and 10 weeks) were used to record the changes of voids/24 h and urodynamic variables. The primary efficacy endpoint was the change in voids/24 h, and the TL value (log[T/L]), a new electromyographic variables showing the extent of DV. Efficacy outcomes at 4 and 10 weeks were compared with the baseline data, using a crossover-designed analysis of variance model. The efficacy analysis of the treatment showed that baclofen was associated with significantly fewer voids/24 h than placebo (mean difference from baseline 5.53 vs 2.70; P = 0.001) and a significant increase in TL (mean difference from baseline -1.78 vs 0.01, P = 0.001). No significant adverse events were reported. A 4-week course of baclofen significantly reduced the number of voids/24 h and increased the TL value in women with DV confirmed by transdermal perineal electromyography. These encouraging results suggest that baclofen could be used for treating DV in women.