Other medications

Other medications that might be employed in the treatment of Parkinson’s disease (PD) include anticholinergics and amantadine.

Anticholinergics

Anticholinergics were commonly used as a PD treatment before the discovery of levodopa. They work by inhibiting the action of a neurotransmitter called acetylcholine, thereby restoring the balance between dopamine and acetylcholine in the brain.

Since the discovery of levodopa, anticholinergics have been used less, but may still be prescribed for younger people with early, mild symptoms, especially tremor. In older people, anticholinergics can cause problems with memory and confusion and, in high doses or in combination with levodopa, may produce unacceptable levels of side effects.

Examples of anticholinergics include orphenadrine, trihexyphenidyl, procyclidine, and benztropine, although these medications are not available in all countries.

Amantadine

Amantadine is a medication that was initially used to treat influenza, but was later found to have an effect in PD via its influence on several neurotransmitters including dopamine, acetylcholine and glutamate. It is sometimes taken (alone or in combination with levodopa) to treat mild PD, and is especially useful in treating levodopa-induced dyskinesias (restless movements).