Dopaminrgics are drugs that increase the effects of dopamine at receptor sites—have been proven to be even more effective than anticholinergics in the treatment of parkinsonism (see the following table).
Dopaminergic agents include amantadine (Symmetrel), apomorphine (Apokyn), bromocriptine (Parlodel), levodopa (Dopar), carbidopa–levodopa (Sinemet), pramipexole (Mirapex), rasagiline (Azilect), and ropinirole (Requip).
Levodopa is the mainstay of treatment for Parkinson disease. This precursor of dopamine crosses the blood–brain barrier and is converted into dopamine. In this way, it acts like a replacement therapy. Although levodopa is almost always given in combination form with carbidopa as a fixed-combination drug (Sinemet),