Complications of intravesical oxybutynin chloride therapy in the pediatric myelomeningocele population

Purpose: We report our experience with the intravesical administration of oxybutynin chloride with particular focus on the incidence and characterization of untoward effects and inconvenience of therapy. Materials and Methods: From 1990 to 1995, 23 children 5 to 11 years old with myelodysplasia were treated with intravesical oxybutynin chloride. Initial dose was 1.25 mg. in 5 cc sterile water instilled during routine catheterization 3 times daily, which was increased as tolerated and clinically indicated. Oral anticholinergic, antispasmodic and sympathomimetic medications were discontinued during therapy. We reviewed therapeutic indications, doses, frequency, duration, reason for discontinuation and untoward effects. Patients/parents were surveyed for convenience of treatment as well as side effects and their timing with respect to drug administration and dose. Results: In 15 patients (65%) treatment was discontinued and oral formulations were resumed or other therapy was required due to side effects, ineffectiveness or inconvenience. Seven patients had untoward effects, ranging from facial flushing and dizziness to agoraphobia and hyperactivity. Six patients discontinued therapy due to side effects after 1 day to 2 years (mode 1 month) at doses of 1.25 to 5 mg., including 5 who previously had side effects from oral oxybutynin chloride. Inconvenience of therapy was noted irrespective of the degree of independence of the child for performing intravesical therapy. Conclusions: Untoward effects and inconvenience are the most common reasons for discontinuing intravesical oxybutynin chloride therapy for neurogenic bladder dysfunction. Children who previously had side effects from oral oxybutynin chloride are more likely to have them during intravesical therapy.