COMT and Parkinson disease: Parkinson’s Disease medications used included levodopa and decarboxylase inhibitor (74%), pramipexole (12.2%), ropinirole (3.8%), entacapone (3.3%), amantadine (2.8%), selegiline (2.0%), and levodopa, decarboxylase inhibitor and COMT inhibitor (1.1%).