Treatments: Anticholinergics

Names:

• Trihexyphenidyl (Artane)
• Benztropine (Cogentin)
• Biperiden,
• Procyclidine
• 2,5 Antihistimines (orphenadrine)

How They Work:

Anticholinergic drugs block the action of the neurotransmitter acetylcholine on neurons in the brain. Normally, acetylcholine and dopamine have opposite effects, at least in the motor areas of the brain. To oversimplify, acetylcholine excites, while dopamine inhibits. Because the level of dopamine is reduced in Parkinson's patients, the neurons responsible for smooth motor control become overstimulated by acetylcholine, causing tremors and rigidity. However, anticholinergic drugs decrease the influence of acetylcholine in the body, either by preventing its production, blocking its receptor sites, or breaking it down chemically. This helps to restores the chemical balance between dopamine and acetylcholine in the motor system.

Thus, anticholinergic drugs are used to decrease tremors, rigidity, and drooling in patients under the age of 60. Unfortunately, acetylcholine is essential for proper neurotransmission in other areas of the brain. After the age of 60, the risk of problems with the central nervous system caused by anticholinergics increases to a great degree. Because of the risks of various side effects, it is suggested that these drugs not be prescribed to people older than 60.

Antihistimines are sometimes prescribed for tremors and rigidity in Parkinson's patients because they have a slight anticholinergic effect.

Side Effects:

Central Nervous System effects:

• sedation
• dysphoric effects
• memory impairment
• acute confusion
• hallucinations

Other effects:

• Dry mouth
• Blurred vision
• Difficulty in urinating
• Constipation

Information from:

Parkinson's Disease at Harvard

WE MOVE