Anticholinergic use in children: Persistence and patterns of therapy

Introduction: Overactive bladder (OAB) symptoms are complex and generally require long-term therapy. Nevertheless, it has been demonstrated that persistence rates of antimuscarinic drug use are low in adults. Better understanding of the treatment patterns of children treated with antimuscarinics could help to improve drug management. Our objective was to evaluate persistence rates of patients under 20 years of age on antimuscarinic therapy over a four-year period. Methods: Patients having received a first-ever antimuscarinic drug prescription between April 2007 and March 2008 were identified using IMS Brogan's Public and Private Drug Plans database. Canadian drug claims data from Private Drug Plans, Regie de l'Assurance Maladie du Quebec, and Ontario Public Drug Plans were analyzed retrospectively. Patients were followed for four years to assess the prescribed drugs, the lines of treatment, and the duration of each treatment. Results: Data were available for 374 patients. The most prescribed drug as a first-line therapy was oxybutynin (87.2%), followed by tolterodine LA (5.9%). Patients refilled their index prescriptions for an average of 429 days. Solifenacin had the highest mean duration of index therapy (765 days). The median number of antimuscarinics prescribed was one. At the end of the followup, 44 patients were still on therapy. Reasons for discontinuation of treatment were not available. Conclusions: Overall discontinuation rate of antimuscarinic therapy in children is comparable to what has been reported in adult patients with OAB. However, children seem to persist on the medication for a longer duration before adherence rates start declining. The low rate of persistence highlights the need to identify the reasons for discontinuation of therapy in children in order to obtain better persistence rates.