## Breadcrumb - [Home](/) - [Living with Parkinson's](/living-with-parkinsons) - [Treatment](/living-with-parkinsons/treatment) - [Prescription Medications](/living-with-parkinsons/treatment/prescription-medications) ## Breadcrumb - [Home](/) - [Living with Parkinson's](/living-with-parkinsons) - [Treatment](/living-with-parkinsons/treatment) - [Prescription Medications](/living-with-parkinsons/treatment/prescription-medications) # Anticholinergic Drugs ## 💡 Quick Summary - Anticholinergic drugs reduce tremor and may help [dystonia](/understanding-parkinsons/movement-symptoms/dystonia "Dystonia") but have limited benefit for other Parkinson’s symptoms. - They can cause cognitive slowing, confusion and [hallucinations](/understanding-parkinsons/non-movement-symptoms/hallucinations-delusions "Hallucinations/Delusions"), especially in people over 70, so they are usually used in younger people. - Common side effects include dry mouth, blurry vision, [constipation](/understanding-parkinsons/non-movement-symptoms/constipation "Constipation & Nausea") and urinary retention. - Medication interactions should be reviewed with a doctor or pharmacist. ![Closeup of doctor's hands pointing to pills](/sites/default/files/styles/no_sizing/public/images/anticholinergicdrugs.jpg?itok=KoNIeFp1) Anticholinergic medications reduce tremor by blocking acetylcholine, a brain chemical that influences movement. Anticholinergics can be helpful for [tremor](/understanding-parkinsons/movement-symptoms/tremor "Tremor") and may ease [dystonia](/understanding-parkinsons/movement-symptoms/dystonia "Dystonia") (painful cramping) associated with [wearing-off](/library/fact-sheets/managing-off-time "Managing "Off" Time in Parkinson's") 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, data from the Parkinson’s Foundation [Parkinson’s Outcomes Project](/advancing-research/our-research/parkinsons-outcomes-project "Parkinson’s Outcomes Project") support 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 - ### Benztropine (Cogentin®) **Available Doses:** 0.5 mg, 1 mg, 2 mg **Typical Treatment Regimen**: 0.5 to 2 mg 2 to 3 times per day **Side Effects**: Confusion, memory issues, hallucinations, dry mouth, blurry vision, urinary retention **Indications for Usage**: Monotherapy (alone) or combination therapy, predominantly for tremor and dystonia in younger people; should be avoided in elderly. Can also be helpful in reducing the amount of saliva to treat [excessive drooling](/understanding-parkinsons/movement-symptoms/drooling "Drooling") due to the side effect of dry mouth. - ### Trihexyphenidyl HCL (formerly Artane®) **Available Doses:** 2 mg, 5 mg tablets; 2 mg or 5 mL elixir **Typical treatment regimen**: 1 to 2 mg 2 to 3 times per day **Side Effects**: Confusion, memory issues, hallucinations, dry mouth, blurry vision, urinary retention **Indications for Usage**: Monotherapy or combination therapy, predominantly for tremor and dystonia in younger people; should be avoided in elderly. Can also be helpful in reducing the amount of saliva to treat [excessive drooling](/understanding-parkinsons/movement-symptoms/drooling "Drooling"), a common PD symptom, due to the side effect of dry mouth. ## Common Side Effects of Anticholinergics - Confusion - Hallucinations - Decreased short-term memory - Dry mouth - Blurry vision - Urinary retention - ### Disclaimers Please note that the side effects listed in the tables that accompany each class of medication are the most commonly experienced. Not all individuals will experience such side effects. Careful adjustments to dosage or the timing of individual doses can often effectively limit or eliminate side effects for many people. Speak to your doctor immediately if you experience any side effects. For a complete description of each drug and its possible side effects, please request a “package insert” from your pharmacist for each drug used. **It is recommended that all prescriptions be filled at the same pharmacy to avoid interactions between medications.** Interactions can be dangerous and even life-threatening, so make sure the pharmacist knows of all medications and supplements being taken, including over-the-counter medications and supplements. **Caution:** Parkinson’s medications may have interactions with certain foods, other medications, vitamins, herbal supplements, over-the-counter cold pills and other remedies. Anyone taking a PD medication should talk to their doctor and pharmacist about potential drug interactions. *Page reviewed by Dr. Chauncey Spears, Clinical Assistant Professor and Dr. Amelia Heston, Movement Disorders Fellow at the University of Michigan.* ## Related Materials Podcasts ### [ Episode 106: Tremors: Coping & Treatment Options ](/library/podcast/106) [Listen Now](/library/podcast/106) Podcasts ### [ Episode 96: PD Medications and Side Effects ](/library/podcast/96) [Listen Now](/library/podcast/96) Podcasts ### [ Episode 10: Young-Onset Parkinson’s 101 ](/library/podcast/10) [Listen Now](/library/podcast/10) ## Related Blog Posts ![giving medications to older man](/sites/default/files/styles/500x360/public/images/medicationadvancingtreatment-blog.jpg?h=f2fcf546&itok=_oFS4UXr) Advancing Research ### [ PD and Medication: Advancing Treatment ](/blog/research/medication-treatment) READ NOW ![Reading pill boxes](/sites/default/files/styles/500x360/public/images/anticholinergicdrugproblems-blog.jpg?h=ed9ce7df&itok=bWQ_5p17) Advancing Research ### [ What's Hot in PD? Short and Long-Term Problems with Anticholinergic Drugs used for Sleep, Bladder, and Tremor Symptoms in Parkinson’s Disease Patients ](/blog/research/anticholinergic-drugs) READ NOW ![group of bikers](/sites/default/files/styles/500x360/public/images/coebiking-blog.png?h=ed9ce7df&itok=O6xzJFUc) Raise Awareness ### [ Center of Excellence Series: Radboud University Medical Center Creates Care for Young-onset Parkinson's Community ](/blog/awareness/radboud-university) READ NOW ### Order a Parkinson’s Hospital Safety Guide The Hospital Safety Guide is a resource for people with Parkinson's and their care partners filled with useful tools and information to prepare for and navigate a hospital stay. [ORDER NOW](/resources-support/pd-library/order-publications) [LEARN MORE](/resources-support/hospital-safety-guide) - Share on Facebook - Share on X - Share on LinkedIn