Closeup of doctor's hands pointing to pills

Anticholinergic medications reduce tremor by blocking acetylcholine, a brain chemical that influences movement. Anticholinergics can be helpful for tremor and may ease dystonia (painful cramping) associated with wearing-off or peak-dose effect, however, they have little effect on other symptoms of Parkinson's disease (PD).

Potential adverse effects include blurred vision, dry mouth, constipation and urinary retention.

Additionally, research from the Parkinson’s Foundation Parkinson’s Outcomes Project supports the finding that cognitive slowing is a side effect of anticholinergics. Older individuals are especially susceptible to confusion and hallucinations on anticholinergics, so these agents should be avoided in people older than 70.

Quick Facts

  • Anticholinergics are the oldest class of medications to treat PD; they were first used in the 1900s.
  • They can be used to reduce the amount of saliva that is produced, and therefore can decrease drooling.
  • These medications can be helpful to younger people with Parkinson's who experience tremor.

Forms of Anticholinergics

Common Side Effects of Anticholinergics

  • Confusion
  • Hallucinations
  • Decreased short-term memory
  • Dry mouth
  • Blurry vision
  • Urinary retention

Page reviewed by Dr. Chauncey Spears, Clinical Assistant Professor and Dr. Amelia Heston, Movement Disorders Fellow at the University of Michigan.

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