Clinical efficacy of istradefylline versus rTMS on Parkinson’s disease in a randomized clinical trial

OBJECTIVE: To compare the efficacy of istradefylline (20 mg/day, 40 mg/day) and repetitive transcranial magnetic stimulation (rTMS) (1 Hz, 10 Hz) as an adjunct therapy to levodopa in the treatment of Parkinson's disease (PD). METHODS: A total of 132 PD patients from China were randomly assigned to receive 20 mg/day istradefylline plus sham-rTMS (Group I), 40 mg/day istradefylline plus sham-rTMS (Group II), placebo plus 1 Hz rTMS (Group III) and placebo plus 10 Hz rTMS (Group IV) for 12 weeks. Unified Parkinson's Disease Rating Scale (UPDRS) part III score was the primary outcome. Clinical Global Impression-Global Improvement (CGI-I) was the secondary outcome. The change in daily off time in Groups I and II was also recorded. RESULTS: After 12 weeks of treatment, the changes in UPDRS part III score were -6.05, -6.39, -5.91 and -6.46 for Groups I, II, III and IV, respectively, and the difference was not significant. The difference in CGI-I among the four groups was not significant. The daily off time was reduced by -1.43 hours in Group I and -1.62 hours in Group II. No severe adverse events occurred among the four groups. CONCLUSION: These results indicate that, as augmentation agents to levodopa in the treatment of PD, istradefylline and rTMS had comparable efficacy and tolerability.