Effects of Coenzyme Q10 (CoQ) in Parkinson Disease

Parkinson disease (PD) is a progressive neurodegenerative disease that affects more than 1,000,000 Americans. Currently there is no proven therapy to reduce the rate of progression of PD. In a previous phase II clinical trial, investigators demonstrated that Coenzyme Q10 (CoQ) at dosages of 300, 600, and 1200 mg/day was safe and well-tolerated in individuals with early, untreated PD. The findings also suggested that CoQ may slow the progressive impairment of PD as measured by the Unified Parkinson Disease Rating Scale (UPDRS). In this study, researchers will conduct a randomized, placebo-controlled, phase III trial of CoQ to confirm and extend the results of the earlier phase II study. The primary objective of this trial is to compare the effect of two dosages of CoQ (1200 and 2400 mg/day) and placebo on the total UPDRS score in people with early PD. The study also will evaluate independent function, cognition, and quality of life. Plasma CoQ levels will be measured at months 1, 8 and 16 and correlated with changes in UPDRS scores. Participants will be randomly assigned to receive a placebo (an inactive substance), 1200 mg/d CoQ, or 2400 mg/d CoQ. They will be evaluated at screening, baseline, and during visits at months 1, 4, 8, 12, and 16. Information gained from this trial could lead to changes in management of people with early PD.