Antiparkinson medications or agents are drugs that are used to combat the symptoms of Parkinson's Disease such as tremors and muscular stiffness. Since Parkinson's is caused by a reduction or lack of dopamine in the basal ganglia (hyperlink?) the majority of antiparkinson agents are geared towards the replacement of dopamine.
These are called dopaminergic antiparkinson agents and they work by stimulating the release of dopamine in the brain or by imitating dopamine so that he body treats it as such. Examples of dopaminergic antiparkinson agents are L-DOPA or levodopa and deprenyl. Another class of antiparkinson medications are anticholinergic antiparkinson agents which work by reducing acetylcholine. Examples of anticholinergic antiparkinson agents include orphenadrine, procyclidin, and trihexyphenidyl.