Introduction

In addition to motor symptoms, bladder dysfunction is a major clinical issue in patients with Parkinson's disease (PD). Istradefylline, a novel non-dopaminergic selective adenosine A2A receptor antagonist, was approved in 2013. We previously reported that Istradefylline improved not only motor symptoms, but also lower urinary tract symptoms (LUTS) in patients with PD in a short-term period. However, the long-term effects of istradefylline for LUTS has not yet been clarified. The aim of this study was to determine the effects of 1 year istradefylline treatment on LUTS in PD patients.

Methods

We enrolled male 12 male PD patients. The mean of age of patients was 66 (61-80) years old, the Hoehn-Yahr stage was 2 (2-3), and disease duration was 9 (4-26) years. The effects of istradefylline (20 mg/day) on LUTS in PD patients with motor complications after 3, 6 months and 1 year of therapy were evaluated based on the International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score (OABSS), King's Health Questionnaire (KHQ) score, 3-day voiding diary, and urinary flow rate and post-voiding residual urine volume before and after its administration.

Results

Motor symptoms significantly improved after 1 year evaluating movement disorder rating scale (P<0.01). Significant improvements were also observed in the answers provided on urinary questionnaires after 1 year treatment (IPSS: 14.4 ± 7.6 vs. 8.5 ± 6.8, OABSS: 6.9 ± 2.8 vs. 5.5 ± 3.7; P<0.05) [breakdown: Table]. Data from the KHQ revealed that the domain of impact on life had significantly improved after 1 year treatment [Table]. And in 3-day voiding diary, nighttime urinary frequency (3.0 ± 1.6 vs. 2.4 ± 0.7; P<0.05). However, no significant changes were observed in the urinary flow rate (Qmax) or post-voiding residual urine volume (RU) between before and after 1 year administration of istradefylline (Qmax (ml/s): 10.7 ± 3.9 vs. 8.0 ± 2.8, RU (ml): 51.0 ± 60.0 vs. 40.5 ± 30.8). No adverse urological effects were observed in any patient.

Conclusions

Istradefylline effectively improved not only motor symptoms, but also LUTS in patients with PD in a long-term period. And the results of the present study confirmed that adenosine A2A receptor antagonists are useful as a new pharmacological treatment for OAB in patients with PD.

Funding

none