Vitamins and entacapone in levodopa-induced hyperhomocysteinemia: a randomized controlled study.

Elevated homocysteine is associated with increased risk of heart disease, stroke, and dementia. Therapy of Parkinson disease (PD) with levodopa elevates homocysteine. The authors conducted a 6-week, multicenter, randomized, double-blind, placebo-controlled trial to test whether folate 1 mg/vitamin B(12) 500 microg or entacapone reduced serum homocysteine in 35 levodopa-treated PD patients. Levodopa initiation caused a small elevation in homocysteine. Vitamin therapy, but not entacapone, resulted in a decrease in homocysteine compared to placebo.