What To Know About Anticholinergics (2023)

Anticholinergics are drugs used to treat involuntary muscle movements. In some cases, these involuntary movements are a result of a physical health condition such as Parkinson's disease or asthma. Other times, they are a side effect of psychiatric medications.

If you have been prescribed an anticholinergic, it's helpful to understand how these medications work and what type of conditions they can help manage or treat. It's also important to know the potential side effects of anticholinergics and precautions associated with this category of drugs.

The Most Important Information to Know About Anticholinergics

  • Anticholinergics are not recommended for older adults due to a greater risk of side effects.
  • When taken in high doses, serious side effects can occur.
  • Anticholinergics can interact negatively with many other drugs.

History of Anticholinergics

Anticholinergics were originally derived from atropine-containing plants like deadly nightshade and thorn apple. As far back as the 17th century, these plants were burned and the smoke was inhaled as a treatment for diseases obstructing the airways.

Over the next several centuries, patients with asthma started using cigarettes and tobacco pipes to inhale the smoke from the burned plants. While this was a popular over-the-counter option, the dosage of atropine the patient received varied depending on how deeply they inhaled and whether they absorbed any of the atropine in their mouths or gastrointestinal tracts.

In the 19th century, anticholinergic agents were introduced into medications for Parkinson’s disease. As other more effective drugs have been developed, the use of anticholinergics to treat Parkinson’s has declined. This is largely due to the more severe side effects that these medications can have on older people.

How Anticholinergics Work

Anticholinergics work by blocking the action of a chemical messenger called acetylcholine. Acetylcholine is responsible for transferring signals that affect communication between nerves and certain types of muscles and organs in several parts of the body.

One of the most common uses of anticholinergics is as a treatment for asthma. These medications help ease asthma symptoms by relaxing and enlarging the airway, which makes breathing easier.

Types of Anticholinergics

Anticholinergics can be split into two broad categories: drugs that are primarily anticholinergic and drugs that are designed for other purposes but produce anticholinergic effects.

Primary Anticholinergics

There are several pure anticholinergic medications and they all work in the same way—by blocking the actions of acetylcholine. These anticholinergics generally cannot be bought over the counter; they can only be prescribed by a physician.

The anticholinergic a healthcare provider might prescribe depends on the condition that is being treated. While there are many that exist, some options include:

  • Atropine: Used to treat eye conditions such as uveitis, and to reduce the secretion of saliva and mucus in the airways during surgery.
  • Bentyl (dicyclomine): Used to treat irritable bowel syndrome (IBS) symptoms.
  • Cogentin (benztropine mesylate) and Trihexyphenidyl HCL: Used to treat symptoms of Parkinson's disease, and to help manage the side effects of certain psychiatric medications.

Trihexyphenidyl was previously available under the brand names Artane and Tremin, but these brands are no longer on the market.

  • Ditropan (oxybutynin):Used to treat overactive bladder.
  • Enablex (darifenacin): Used to treat urinary incontinence.
  • Tudorza Pressair (aclidinium): Used to treat respiratory conditions, like asthma.

Drugs With Anticholinergic Effects

Some prescription and over-the-counter medications also have anticholinergic properties. This means that they can block the actions of acetylcholine, even though they are not formulated for that purpose.

Medications that fall into this category include:

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  • Antipsychotic medications: Thorazine (chlorpromazine), Clozaril (clozapine), Zyprexa (olanzapine)
  • First-generation antihistamines: Benadryl (diphenhydramine), Vistaril (hydroxyzine), and Tavist (clemastine)
  • Tricyclic antidepressants: Elavil (amitriptyline), Anafranil (clomipramine), and Tofranil (imipramine)

Uses for Anticholinergics

Anticholinergics may be used to help treat several health conditions, including:

  • Allergies
  • Asthma
  • Chronic obstructive pulmonary disease (COPD)
  • Diarrhea
  • Gastrointestinal disorders
  • Hyperhidrosis (excessive sweating)
  • Motion sickness
  • Muscle spasms
  • Overactive bladder
  • Parkinson's disease
  • Poisoning
  • Urinary incontinence

Anticholinergics can also be used during surgery to reduce bronchial secretions and dilate the airways, decreasing airway resistance during the procedure.

Side Effects of Anticholinergics

People taking anticholinergics can experience side effects. Some of these effects are more common than others, some are severe, and some effects can be long-term.

Unless necessary, the use of anticholinergics should be avoided in older people as side effects (particularly those related to cognitive function) are more common and severe. This is due to an older person's reduced ability to break down, distribute, and clear these drugs.

Common Side Effects

The side effects experienced most often with anticholinergic medications include:

  • Cognitive impairment
  • Constipation
  • Dry mouth
  • Functional difficulties, or trouble performing everyday activities
  • Urinary retention (when the bladder does not fully empty during urination)

Severe Side Effects

When anticholinergics are used at high doses, one may experience severe side effects. Severe side effects are also more common in older people, which is why anticholinergics are used with caution, if at all, in the elderly.

Some of the serious side effects that can occur with anticholinergics include:

  • Blood pressure changes (either low or high)
  • Delirium
  • Dilated pupils
  • Fever
  • Hallucinations
  • Increased heartbeat
  • Trouble regulating body temperature, due to increased heat production and inability to sweat

Overdose Warning

Severe side effects are often an indication of an anticholinergic overdose. This is known as anticholinergic syndrome, poisoning, or toxicity and requires immediate medical attention.

Long-Term Side Effects

Some research suggests that long-term use of anticholinergics may contribute to cognitive decline. A 2018 study evaluated the risk of older people who used anticholinergics long-term and found an association between long-term use and an increased risk of developing dementia.

Long-term use of anticholinergics is also not recommended for people with schizophrenia. The reason for this is that, over time, the use of anticholinergics can make these individuals' cognitive impairment worse, impacting their quality of life.

Precautions for Anticholinergics

Certain precautions need to be taken when using anticholinergics. They include:

  • Overheating: It’s important to prevent your body from overheating by staying hydrated when on anticholinergics, especially if one of the side effects you experience is decreased sweating. When there’s a decrease in how much you sweat, your body temperature rises and you are more likely to experience heat strokes.
  • Overdose: Taking several anticholinergic drugs at once—such as by taking numerous over-the-counter cold medicines—can result in an overdose. Signs of overdose include confusion, hallucinations, rapid heartbeat, fever, and dizziness.
  • Use with alcohol: Like with almost all medications, the use of anticholinergics with alcohol is strongly discouraged.
  • Other medical conditions: People with certain medical conditions may be discouraged from using anticholinergics.Talk with your physician if you have any medical conditions before taking anticholinergic drugs.
  • Use with other drugs: People who are already taking certain other drugs shouldn’t take anticholinergics. Let your healthcare provider or pharmacist know if you are taking other medications and have been prescribed an anticholinergic agent.

14 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Scullion JE. The development of anticholinergics in the management of COPD. Int J Chron Obstruct Pulmon Dis. 2007;2(1):33-40. doi:10.2147/copd.2007.2.1.33

  2. O'Donnell LK, Gnjidic D, Nahas R, Bell JS, Hilmer SN. Anticholinergic burden: considerations for older adults. J Pharm Pract Res. 2016;47(1):1-11. doi:10.1002/jppr.1303

  3. National Institute of Diabetes and Digestive and Kidney Diseases. Anticholinergic agents. In: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet].

  4. Lertxundi U, Domingo-Echaburu S, Hernandez R, Peral J, Medrano J. Expert-based drug lists to measure anticholinergic burden: similar names, different results. Psychogeriatrics. 2013;13(1):17-24. doi:10.1111/j.1479-8301.2012.00418.x

  5. MedlinePlus. Trihexyphenidyl.

  6. Joshi YB, Thomas ML, Braff DL, et al. Anticholinergic medication burden—Associated cognitive impairment in schizophrenia. Am J Psychiatry. 2021;178(9):838-847. doi:10.1176/appi.ajp.2020.20081212

  7. Galvão Oliveira M,Wildes Amorim W,Rodrigues-Neto AJ. Reviewing the safety of loratadine for elderly adults: A potential shortcoming of the 2012 Beers criteria. J Am Ger Soc. 2014;62(8):1618-1619. doi:10.1111/jgs.12957

  8. López-Álvarez J, Sevilla-Llewellyn-Jones J, Agüera-Ortiz L. Anticholinergic drugs in geriatric psychopharmacology. Front Neurosci. 2019;13:1309. doi:10.3389/fnins.2019.01309

  9. Saraswat V. Effects of anaesthesia techniques and drugs on pulmonary function. Indian J Anaesth. 2015;59(9):557-564. doi:10.4103/0019-5049.165850

  10. Harvard Health Publishing. Two types of drugs you may want to avoid for the sake of your brain.

    (Video) Anticholinergic Medication Side Effects/Symptoms - Pharmacology | @LevelUpRN

  11. Dawson AH, Buckley NA. Pharmacological management of anticholinergic delirium - theory, evidence and practice. Brit J Clin Pharmacol. 2015;81(3):516-524. doi:10.1111/bcp.12839

  12. Richardson K, Fox C, Maidment I, et al. Anticholinergic drugs and risk of dementia: case-control study. BMJ. 2018;361:k1315. doi:10.1136/bmj.k1315

  13. Ogino S, Miyamoto S, Miyake N, Yamguchi N. Benefits and limits of anticholinergic use in schizophrenia: Focusing on its effect on cognitive function. Psychiatry Clin Neurosci. 2013;68(1):37-49. doi:10.1111/pcn.12088

  14. Khan A, Singh G, Jacob J. A rare presentation of anticholinergic toxicity in a young patient due to over-the-counter cold medicines. Cureus. 2021;13(3):e13919. doi:10.7759/cureus.13919

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What To Know About Anticholinergics (1)

By Toketemu Ohwovoriole
Toketemu has been multimedia storyteller for the last four years. Her expertise focuses primarily on mental wellness and women’s health topics.

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(Video) Anticholinergic Toxicity Side Effects


What To Know About Anticholinergics? ›

Anticholinergic medications (shorthand: "anticholinergics") are drugs that block and inhibit the activity of the neurotransmitter acetylcholine (ACh) at both central and peripheral nervous system synapses.

What are the precautions of anticholinergics? ›

Anticholinergics are known to cause confusion, memory loss, and worsening mental function in people who are older than 65 years. In fact, recent studies have linked use of anticholinergics with increased risk of dementia. Also, people with the following conditions shouldn't use anticholinergics: myasthenia gravis.

What is the health teaching about anticholinergics? ›

Anticholinergics are used for maintenance therapy of bronchoconstriction associated with asthma, chronic bronchitis, and emphysema. Anticholinergics should be used with caution with the elderly and can cause cough, drying of the nasal mucosa, nervousness, nausea, GI upset, headaches, and dizziness.

What is an easy way to understand anticholinergic? ›

Anticholinergic drugs oppose (or reduce) the effects of cholinergic drugs. They work by blocking acetylcholine receptors or preventing the release of acetylcholine into the synapse. So, in the simplest sense, anticholinergics are drugs that can turn off the system in your body that causes the fight and flight reaction.

What are the 4 main uses of anticholinergic drugs? ›

Anticholinergic drugs can help treat a range of conditions, including COPD, an overactive bladder, gastrointestinal disorders, and symptoms of Parkinson's disease. Anticholinergics are only available via prescription, so it is best to speak with a doctor about which type can help treat specific conditions.

What are 4 major side effects of anticholinergic drugs? ›

At high dosages and approaching the range of anticholinergic toxicity, central adverse effects include signs of agitation, confusion, delirium, and seizures.

Which patients should avoid anticholinergics? ›

Anticholinergic drugs should not be used in conditions such as:
  • benign prostatic hypertrophy (BPH)
  • angle closure glaucoma.
  • myasthenia gravis.
  • Alzheimer's disease.
  • bowel blockage.
  • urinary tract blockage or urinary hesitancy.
Aug 25, 2022

What is the risk of anticholinergic side effects? ›

Medications with anticholinergic activity can cause side effects. This includes dry mouth, constipation, and eye problems. More seriously, anticholinergics can lead to serious heart problems or anticholinergic toxicity. When used for a long time, they've also been linked to a greater risk of dementia.

What drugs interact with anticholinergics? ›

Anticholinergic effect is enhanced by:
  • Antidepressants, including amitriptyline, nortriptyline, paroxetine, fluoxetine and monoamine oxidase inhibitors (MAOI)
  • Antihistamines used to treat asthma, hay fever and urticaria.
  • Tiotropium, ipratropium bromide and potassium chloride tablets.

What is the primary side effect of anticholinergics include? ›

Typical symptoms include dry mouth, constipation, urinary retention, bowel obstruction, dilated pupils, blurred vision, increased heart rate, and decreased sweating (Table 1).

How do you manage anticholinergic effects? ›

The antidote for anticholinergic toxicity is physostigmine salicylate. Physostigmine is the only reversible acetylcholinesterase inhibitor capable of directly antagonizing the CNS manifestations of anticholinergic toxicity; it is an uncharged tertiary amine that efficiently crosses the blood-brain barrier.

What is the common cause of anticholinergic? ›

Anticholinergic syndrome may be caused by intentional overdose, inadvertent ingestion, medical noncompliance, or geriatric polypharmacy. Systemic effects also have resulted from topical eye drops. Anticholinergic syndrome commonly follows the ingestion of a wide variety of prescription and over-the-counter medications.

Is Benadryl an anticholinergic drug? ›

Benadryl is both an antihistamine and an anticholinergic medication. This means that Benadryl also blocks the effect of acetylcholine. This is a chemical in the brain that helps send messages between cells. Blocking acetylcholine can cause temporary drowsiness, confusion, and memory loss.

What is the most commonly used anticholinergic drug? ›

Tricyclic antidepressants (TCAs) like nortriptyline (Pamelor), doxepin, and amitriptyline. Common OTC medications like diphenhydramine (Benadryl)

What are the long term side effects of anticholinergic drugs? ›

Anticholinergic medications can cause dry mouth, low blood pressure and also confusion, difficulty concentrating, agitation and memory problems. These side effects have been assumed to be temporary, but recent studies suggest that long term use of anticholinergics may cause cognitive decline and dementia.

Is albuterol an anticholinergic? ›

Other Key Facts: o Ipratropium and ipratropium/albuterol solutions for nebulization are the only inhaled anticholinergic products that are currently available generically. 1.

Is Zyrtec an anticholinergic? ›

Cetirizine (Zyrtec) has low anticholinergic properties, and is thought to be at lower risk than the older drugs.

How do anticholinergics affect the heart? ›

Anticholinergics have two opposite effects on heart function [5]: suppression of parasympathetic control of heart rate and indirect reduction in sympathetic input to the heart. When the effect of anticholinergics on parasympathetic nerves is more intense, it increases the risk of tachyarrhythmia and ischemia.

Is Tylenol an anticholinergic? ›

In addition to prescription medications, many common over-the-counter drugs have anticholinergic properties, including antihistamines such as Benadryl and Chlor-Trimeton, and sleep aids such as Tylenol PM, Aleve PM, and Nytol.

Why are anticholinergic drugs bad? ›

A: These medications block the action of acetylcholine in the brain and body. Acetylcholine is a neurotransmitter that sends signals in the nervous system. Medications that block acetylcholine's action can cause side effects including drowsiness, constipation, difficulty urinating, and dry mouth and eyes.

Why should anticholinergics be avoided? ›

These medications have many side effects, including impaired cognition, drowsiness, and constipation. Several cohort studies have raised concern regarding an association between higher exposure to anticholinergics and increased risk of dementia.

What are examples of anticholinergic toxicity? ›

Examples of classes of medications with anticholinergic properties include antihistamines (eg, diphenhydramine), tricyclic antidepressants (TCAs; eg, amitriptyline), sleep aids (eg, doxylamine), cold preparations, scopolamine (hyoscine), and tainted illicit street drugs (eg, heroin "cut" with scopolamine).

Do anticholinergics cause weight gain? ›

Tricyclic antidepressants (TCAs)are known for their anticholinergic side effects; however,weight gain can be an unfortunate side effect as well.

What are the risks of anticholinergics in the elderly? ›

Older adults are more sensitive to adverse events associated with anticholinergics, including confusion, dry mouth, blurry vision, constipation, urinary retention, decreased perspiration, and excess sedation. Anticholinergics have also been associated with increased risk of dementia.

How do anticholinergics affect urination? ›

Anticholinergic drugs block the action of the chemical messenger acetylcholine. Acetylcholine sends signals to your brain that trigger bladder contractions associated with an overactive bladder. These bladder contractions can cause a need to urinate even when the bladder isn't full.

What are three common side effects seen with both anticholinergics and antihistamines? ›

Antihistamine Risks and Anticholinergic Syndrome

This leads to significant central nervous system side effects, including sedation, drowsiness, somnolence, fatigue, cognitive decline, psychomotor effects, and loss of coordination.

Do anticholinergics increase heart rate? ›

Anticholinergics increase heart rate and can be used to treat bradycardia. They are also used to reverse cholinergic overstimulation caused by cholinesterase inhibitors and neuromuscular blockers in anesthesia.

What effects do anticholinergics have on the lungs? ›

Respiratory anticholinergics make breathing easier by relaxing the smooth muscles of bronchial tubes, improving lung function, and reducing mucus secretion in the respiratory system.

What is the most common side effect of inhaled anticholinergics? ›

The main side effects of anticholinergics like ipratropium include: a dry mouth. constipation. a cough.

Which antihistamine is anticholinergic? ›

In vivo, five antihistamines showed anticholinergic activity: cyproheptadine>promethazine>desloratadine>loratadine>diphenhydramine.

Is anticholinergic a sedative? ›

many anticholinergic medicines also have sedative properties. medicines with sedative properties have been linked to depressive symptoms, worsening cognition, respiratory depression, impaired muscle strength and falls and fractures.

Why can't over 65s take Benadryl? ›

Acrivastine is not recommended for people over 65 because very little research on the medicine has been done in this age group. Talk to your pharmacist or doctor if you're over 65 and want to take acrivastine.

Is Xanax an anticholinergic drug? ›

Physicians may not realize that the anti-anxiety agent alprazolam (Xanax) has anticholinergic activity.

What are 5 drugs to avoid in the elderly? ›

Here are 5 groups of drugs to avoid:
  • NSAIDs. (non-steroidal inflammatory drugs) such as ibuprofen (Advil, Motrin), naproxen (Aleve) and aspirin can increase risk of stomach ulcers, blood pressure, heart failure and affect kidneys.
  • Antihistamines. ...
  • Sleeping aids. ...
  • Benzodiazepines. ...
  • Opioids.
Sep 20, 2016

Why do anticholinergics cause memory loss? ›

But we do know that anticholinergic drugs can cause confusion and increase fall risk in older people. Anticholinergic drugs block the action of acetylcholine. This substance transmits messages in the nervous system. In the brain, acetylcholine is involved in learning and memory.

What do anticholinergic drugs end in? ›

Any drug that ends in “-pium” is an anticholinergic.

Which inhalers are anticholinergic? ›

Anticholinergic inhalers include:
  • Aclidinium (Tudorza Pressair)
  • Glycopyrronium (Seebri Neohaler)
  • Ipratropium (Atrovent)
  • Tiotropium (Spiriva)
  • Umeclidinium (Incruse Ellipta)
  • Revefenacin (Yupelri)

What do inhaled anticholinergics do? ›

Also known as long-acting muscarinic antagonists (LAMA), inhaled anticholinergics block the muscarinic receptors on the bronchial smooth muscles and the exocrine gland cells in the bronchial passage. Blocking acetylcholine activity in the airway relaxes the airway muscles, reduces mucus congestion, and eases breathing.

What are the nursing considerations when administering anticholinergic agents? ›

These are vital nursing interventions done in patients who are taking anticholinergics:
  • Ensure proper administration of the drug to ensure effective use and decrease the risk of adverse effects.
  • Monitor patient response (e.g., blood pressure, ECG, urine output) for changes that may indicate need to adjust dose.
May 6, 2023

What are common adverse effects of anticholinergics? ›

Typical symptoms include dry mouth, constipation, urinary retention, bowel obstruction, dilated pupils, blurred vision, increased heart rate, and decreased sweating (Table 1).

What is the problem with anticholinergic drugs? ›

Undesirable anticholinergic effects

Peripheral anticholinergic effects include constipation, dry mouth, dry eyes, blurred vision (mydriasis), tachycardia and urinary retention. Central nervous system effects include agitation, confusion, delirium, hallucinations and cognitive impairment3.

How do anticholinergics affect heart rate? ›

Anticholinergics have two opposite effects on heart function [5]: suppression of parasympathetic control of heart rate and indirect reduction in sympathetic input to the heart. When the effect of anticholinergics on parasympathetic nerves is more intense, it increases the risk of tachyarrhythmia and ischemia.

What do anticholinergics do to the heart? ›

Anticholinergics increase heart rate and can be used to treat bradycardia. They are also used to reverse cholinergic overstimulation caused by cholinesterase inhibitors and neuromuscular blockers in anesthesia.

What happens with too much anticholinergic? ›

anticholinergic toxidrome

Most often causes agitated delirium (often with hallucinations, incoherent speech, picking at the air or objects). More severe cases may present with seizure and/or coma. CNS effects may persist after peripheral features have resolved.

Why do anticholinergics worsen dementia? ›

Anticholinergic drugs inhibit acetylcholine, which could create an effect similar to the acetylcholine decline associated with Alzheimer's.


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