Imipramine for refractory daytime incontinence in the pediatric population

Lower urinary tract (LUT) and voiding dysfunction constitute a large percentage of pediatric urology referrals. Children with urinary incontinence unresponsive to behavioral modifications and traditional pharmacotherapy including anticholinergics and alpha blockers remain a challenge. We evaluated the impact of imipramine on treatment outcomes in children with refractory incontinence.

Children ≤18 years of age with refractory non-neurogenic daytime incontinence prescribed imipramine were identified. Patient demographics and baseline testing were assessed, as well as medication dosing and side effects of all patients. The Vancouver Symptom Score (VSS) was completed at the initial consultation and each subsequent clinic visit. The questionnaire was self-administered and completed by patients and/or parents. Treatment success was defined as per the International Children's Continence Society (ICCS).

One hundred and three patients (55 males and 48 females) met the inclusion criteria. The intention-to-treat response rate was 65% (complete 44, partial response 23). Sixteen (15.6%) patients were non-responders and 20 (19.4%) were lost to follow-up. There was no statistical difference between all groups with regards to age, baseline VSS, and dose. Of those children with complete follow-up (n = 83), 44 (53%) experienced complete treatment response. Pre- and post-VSS were statistically different in both complete and partial response groups (complete 19.5-9.5; p < 0.0001; partial 19.7-13; p = 0.0002) (Table). Side effects were reported by 11 out of 83 (13.3%) patients; partial responders experienced a higher likelihood of side effects (26.1%; p = 0.03).

The mainstay of LUT dysfunction management in children is implementation of a bowel program and timed voiding regimen, with additional treatment modalities and pharmacotherapy added depending upon prevailing symptomatology. Daytime incontinence refractory urotherapy, anticholinergics, and/or non-selective alpha blockers can be difficult to treat, and can be unresponsive to parasacral transcutaneous electrical nerve stimulation (TENS) and percutaneous tibial nerve stimulation (PTNS). We observed that over half of children with refractory daytime incontinence reported complete resolution of daytime accidents with imipramine. Limitations of the study include the retrospective nature, relatively small sample size and lack of control group.

Two-thirds of children with refractory daytime incontinence experienced treatment response to imipramine, adding a valuable tool to the pediatric urologist's armamentarium in managing select, challenging patients.