Oxybutynin is the standard drug for management of overactive bladder (OAB) in children. In some cases, the medication is not tolerated due to its side effect profile or is inconvenient for the caretakers to administer multiple times a day. Although extended release oral formulations are an option, their use is limited by the child’s ability to swallow tablets. Herein, we report our experience with transdermal oxybutynin patch (TOP) as an alternative in a selected patient population without neurogenic compromise.
Consecutive patients assessed in a Nurse Practitioner urology clinic over a one-year period, diagnosed with OAB and with minimum follow-up of 3 months, were included. Children with neurogenic conditions were excluded. TOP starting dose was 3.9mg/day based on product design (Oxytrol®). Demographics and outcomes data were retrospectively collected, including flow rate and voiding diary information, previous anticholinergic therapy, and TOP tolerance. The primary outcome, symptomatic response, was defined as improvement or resolution of lower urinary tract symptoms.
35 children met inclusion criteria (mean age=8 years, range 4-16; 50% male; follow-up 3-6 months). In 69% (24/35) there was previous exposure to oxybutinin, which was discontinued due to intolerable side effects (dry mouth, constipation, behaviour changes). Overall, 34/35(97%) reported good symptom response (complete resolution in 20; improvement in 14). The main side effect was skin irritation at TOP site (35%), leading to discontinuation in 20%. Mean bladder capacity increased from 110cc to 139 cc at follow up. There were no reports of worsening constipation, blurred vision, heat intolerance, or behaviour changes with use of TOP.
Our data suggests that the use of TOP is a viable alternative for children with OAB who do not tolerate other formulations of oxybutynin or are unable to swallow extended-release tablets. Transdermal administration appears to a promising delivery route that merits further evaluation in the pediatric setting.