Transcutaneous Electrical Nerve Stimulation Combined with Oxybutynin is Superior to Monotherapy in Children with Urge Incontinence: A Randomized, Placebo Controlled Study

PURPOSE: To evaluate if combination therapy with TENS and oxybutynin results in a superior treatment response than monotherapy with the two modalities in childhood urge incontinence.

MATERIALS AND METHODS: In this placebo-controlled study 66 urge incontinent children (mean age 7.3 ± 1.6 years) were randomized into three treatment groups. Group 1: active TENS + active oxybutynin (n = 22). Group 2: active TENS + placebo oxybutynin (n = 21). Group 3: active oxybutynin + placebo TENS (n = 23). The children received active/placebo TENS over the sacral S2-S3 outflow for two hours daily in combination with 5 mg x 2/day of active/placebo oxybutynin. The intervention period was 10 weeks. Primary outcome was number of wet days/week. Secondary outcomes were severity of incontinence, frequency, MVV/EBC, AVV/EBC and VAS score.

RESULTS: Combination therapy was superior to oxybutynin monotherapy (P = 0.05) with an 83% greater chance of response in children receiving combination therapy. Active TENS/active oxybutynin was also significantly more effective compared to active TENS monotherapy regarding improvement in number of wet days/week (mean difference = -2.28, [CI: -4.06; -0.49]), severity of incontinence (mean difference = -3.11, [CI: -5.98; -0.23]), and voiding frequency per day (mean difference = -2.82, [CI: -4.48; -1.17]).

CONCLUSION: TENS in combination with oxybutynin for childhood urge incontinence was shown to be superior to both TENS and oxybutynin monotherapy although the latter only reached borderline statistical significance. Furthermore, TENS treatment was associated with a reduced risk of oxybutynin induced post-void residual urine > 20 ml.