Comparison of electric stimulation and oxybutynin chloride in management of overactive bladder with special reference to urinary urgency: a randomized placebo-controlled trial

Abstract

Objectives: To compare the efficacy of electric stimulation (ES), oxybutynin, and placebo in managing the symptom complex of overactive bladder (OAB), particularly urgency.

Methods: A randomized placebo-controlled trial was conducted for 68 patients with OAB, placing emphasis on urinary urgency. The interventions for the 12-week treatment period, conducted by the physiotherapist, who was unaware of the progress and outcome, included a vaginal ES program using biphasic symmetric, pulsed current with a 10-Hz frequency, 400-micros pulse width, 10/5 duty cycle, and varying intensity; and oxybutynin (2.5 mg) or placebo three times per day. Identical preintervention and postintervention assessments included the measurement of warning time, urodynamics, voiding diaries, and King's Health Questionnaire.

Results: Of the 68 women who completed this study, 24 were in the ES, 23 in the oxybutynin, and 21 in the placebo group. The between-group comparison showed that significant improvements in daily voided volume, pad count, number of urgency and nocturia episodes, and the domain 2 score and total score of the King's Health Questionnaire existed between the ES and the other groups (all P < or = 0.050). The changes in warning time, maximal voided volume, number of urgency episodes, and frequency were significantly improved between oxybutynin and placebo (all P < 0.013). Additionally, a comparison of the voided volume in uroflowmetry between the ES and placebo groups revealed a greater difference after treatment (P = 0.013). The reduction rate of OAB was 58.4% for the ES, 39.1% for the oxybutynin, and 9.5% for the placebo group (P = 0.036).

Conclusions: ES had the greatest subjective outcome for OAB and was the most effective of the three treatments. Oxybutynin was more effective than placebo.