Clinical Health Updates

Coenzyme Q10 ineffective in Parkinson’s disease

Clinical Question:
Does coenzyme Q10 improve symptoms in patients with midstage Parkinson’s disease?

Bottom Line:
Coenzyme Q10, when added to stable drug regimens, is no better than placebo in improving symptoms of midstage Parkinson’s disease.

Storch A, Jost WH, Vieregge P, et al., for the German Coenzyme Q10 Study Group. Randomized, double-blind, placebo-controlled trial on symptomatic effects of coenzyme Q10 in Parkinson disease. Arch Neurol 2007;64:938-944.

Study Design:
Randomized controlled trial (double-blinded)

Major hallmarks in the pathophysiology of Parkinson disease are cellular energy depletion and oxidative stress leading to cellular dysfunction and death. Coenzyme Q(10) (CoQ(10)) is an electron acceptor bridging mitochondrial complexes I and II/III and a potent antioxidant that consistently partially recovers the function of dopaminergic neurons. Given the background above the authors then determined whether nanoparticular CoQ(10) is safe and displays symptomatic effects in patients with midstage Parkinson disease without motor fluctuations. They did a multicenter, randomized, double-blind, placebo-controlled, stratified, parallel-group, single-dose trial. The participating clinics are academic and nonacademic movement disorder clinics. One hundred thirty-one patients with Parkinson disease without motor fluctuations and a stable antiparkinsonian treatment were included. Intervention Random assignment to placebo or nanoparticular CoQ(10) (100 mg 3 times a day) for a treatment period of 3 months. Stratification criterion was levodopa treatment. The subjects underwent evaluation with the Unified Parkinson’s Disease Rating Scale (UPDRS) at each visit on a monthly basis. The primary outcome variable was the change of the sum score of the UPDRS parts II and III between the baseline and 3-month visits. One hundred thirty-one subjects were randomized according to the protocol. The mean changes of the sum UPDRS parts II/III score were -3.69 for the placebo group and -3.33 for the CoQ(10) group (P = .82). Statistical analysis according to the stratification did not result in significant changes of the primary outcome variable. No secondary outcome measure showed a significant change between the placebo group and the CoQ(10) group. The frequency and quality of adverse events were similar in both treatment groups.