Urodynamic effects and safety of modified intravesical oxybutynin chloride in patients with neurogenic detrusor overactivity: 3 years experience


Motoaki Saito md phd, Department of Surgery, Division of Urology, Tottori University Faculty of Medicine, 86 Nishimachi, Yonago, Tottori 683-0826, Japan.
Email: saitomo@grape.med.tottori-u.ac.jp


Abstract  Background:  Intravesical oxybutynin chloride with hydroxypropylcellulose (HPC) (modified intravesical oxybutynin) has been reported to be effective for treatment of overactive bladder. We reported the short-term effects of modified intravesical oxybutynin previously. In the present article, we detail the results of a 3-year follow-up study of patients from our previous analysis and report the efficacy and side-effects of modified intravesical oxybutynin.

Methods:  Modified intravesical oxybutynin (5 mg/10 mL, twice a day) was applied for more than 3 years to six neurogenic overactive detrusor patients (three men and three women, average age 53.3 years) who were not satisfied with oral anticholinergic agents or the other therapy. A cystometogram (CMG) was performed before, 1 week after and 3 years after the start of modified intravesical oxybutynin treatment. We evaluated the patient's satisfaction of this treatment after 4 weeks and again after 3 years. We compared the patients’ answers before and after the therapy (excellent, good, fair, unchanged and worse). We also monitored systemic and topical side-effects in these patients during this period.

Results:  CMG studies showed that two of six patients no longer exhibited uninhibited contraction 1 week after the treatment and that the cystocapacity of patients before, 1 week after and 3 years after the initial modified intravesical oxybutynin was 129.7 ± 19.4, 283.5 ± 40.4 and 286.8 ± 38.1 mL, respectively. For the evaluation of patients’ satisfaction with this treatment, four patients considered the therapy excellent and one patient described it as good after both 4 weeks and after 3 years. Two patients dropped out of the study; one developed left ureteral cancer (2.25 years) and the other developed ileus (1.5 years). Dry mouth and acute cystitis were observed in both patients.

Conclusion:  Modified intravesical oxybutynin is an effective and relatively safe option of therapy for overactive bladder patients. However, this therapy requires careful observation for emergent side-effects.