Digestive Health Irritable Bowel Syndrome Anticholinergic Drugs By Barbara Bolen, PhD Barbara Bolen, PhD Twitter Barbara Bolen, PhD, is a licensed clinical psychologist and health coach. She has written multiple books focused on living with irritable bowel syndrome. Learn about our editorial process Updated on November 24, 2021 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Jay N. Yepuri, MD, MS Medically reviewed by Jay N. Yepuri, MD, MS Facebook LinkedIn Twitter Jay Yepuri, MD, MS, is a board-certified gastroenterologist and a practicing partner at Digestive Health Associates of Texas (DHAT). Learn about our Medical Expert Board Print Table of Contents View All Table of Contents How They Work Side Effects Benefits Unintended Anticholinergic Effects Frequently Asked Questions Anticholinergics are a broad class of drug used to treat a variety of medical conditions that affect the contraction and relaxation of muscles. They include medications used to treat overactive bladder, Parkinson's disease, diarrhea, vomiting, asthma, chronic obstructive pulmonary disease (COPD), muscle spasms, irritable bowel syndrome (IBS), and other conditions which involve involuntary muscle movement. SDI Productions / Getty Images How These Drugs Work Acetylcholine is a substance produced by the body that functions as a neurotransmitter. It acts on nerve cells to deliver chemical messages to the brain. By doing so, acetylcholine can regulate certain biological functions either by speeding them up or slowing them down. These include skeletal muscles involved in movement and smooth muscles found in the heart, stomach, intestines, urinary tract, and the lungs. The cells involved in the contraction of these muscles have nerve receptors. Those receptive to acetylcholine are considered cholinergic. When faced with abnormal muscle function, there are drugs that can block acetylcholine by binding to the cholinergic receptors. Without the means to deliver the chemical messages, the contractions can be stopped and the symptoms relieved. We refer to this as the anticholinergic effect. Anticholinergic Side Effects In addition to muscle contractions, certain types of acetylcholine regulate memory, learning, and sensations. Since anticholinergic drugs aren’t specific to the types of receptor they block, they can trigger a range of side effects impacting both the body and mind. These include: Dry mouth due to the inhibition of the salivary glandsSore throat due to decreased mucus productionAbsence of sweatingIncreased body temperatureLight sensitivity due to slowed pupil dilationBlurred vision or double visionIncreased heart rate to compensate for changes in vascular functionPoor coordination due to altered muscle controlUrinary incontinence when sleepingBowel leakageConfusionMemory problemsIncoherenceInability to concentrateThe tendency to be startled easilyHallucinationsDementia Benefits of the Anticholinergic Effect A number of drugs achieve their therapeutic goals because of the anticholinergic effect. By slowing bowel movement, for example, a person may find relief from diarrhea. Similarly, the breathing restriction associated with asthma and COPD can be improved when the cholinergic receptors of lungs are blocked. Antispasmodics are one class of drug in which the anticholinergic effect is considered beneficial. While side effects are common, short-term use combined with low dosage usually means that the symptoms are manageable. Antispasmodic Drugs Antispasmodic drugs with an anticholinergic effect include:Bentyl (dicyclomine)Buscopan (hyoscine butylbromide)Levsin (hyoscyamine)Lomotil (atropine/diphenoxylate)Enablex (darifenacin)Pamine (methylscopalamine)Spiriva (tiotropium bromide)Symmetrel (amantadine)Vesicare (solifenacin) Unintended Anticholinergic Effects On the other hand, there are drugs that have an unintended anticholinergic effect. They include certain antidepressants and antipsychotics which increase or decrease dopamine and serotonin neurotransmitters to alter a person’s mood. In some cases, the drugs can block acetylcholine and lead to anticholinergic side effects. The challenge, of course, is that antidepressants and antipsychotics are often prescribed over the long term, making the management of symptoms all the more difficult. Antidepressants Antidepressants and antipsychotics with anticholinergic effects include:Elavil (amitriptyline)Norpramin (desipramine)Tofranil (imipramine)Pamelor (nortriptyline)Paxil (paroxetine)Thorazine (chlorpromazine)Clozaril (clozapine)Zyprexa (olanzapine)Mellaril (thioridazine) In between both of these extremes, there are times when low-dose antidepressants can be used to treat chronic pain and IBS. A similar effect is achieved with certain low-dose antipsychotics and Parkinson's disease. By weighing the pros and cons of the anticholinergic effect, healthcare providers can find the right drug and dosage by which to deliver treatment without the burden of side effects. A Word From Verywell If you are experiencing intolerable side effects due to the anticholinergic effects of a drug, speak with your healthcare provider. Depending on your healthcare provider, the practitioner may be able to decrease the dosage or find the appropriate substitution. However, you should not discontinue any drug without first speaking with your healthcare provider. Doing so can sometimes cause ill effects (especially with certain antidepressants) unless treatment is gradually tapered off. Frequently Asked Questions What is anticholinergic syndrome? Anticholinergic syndrome is caused by abruptly stopping the use of anticholinergic drugs after chronic (long-term) use. The condition can cause restlessness, heart palpitations, anxiety, and other effects. The condition can be prevented by gradually decreasing the dosage. What are examples of anticholinergic drugs? A few examples of anticholinergic drugs are antidepressants like Paxil (paroxetine), Thorazine (chlorpromazine), and Clozaril (clozapine). There are many other anticholinergic drugs used for different purposes, such as treatment of an overactive bladder, diarrhea, vomiting, asthma, muscle spasms, irritable bowel syndrome (IBS), and more. What are antimuscarinics? Antimuscarinics are one of two subtypes of anticholinergic drugs (the other being antinicotinics). Was this page helpful? Thanks for your feedback! One of the most challenging aspects of having IBS is trying to figure out what's safe to eat. Our recipe guide makes it easier. Sign up and get yours now! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 4 Sources Verywell Health 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. Ogino S, Miyamoto S, Miyake N, Yamaguchi N. Benefits and limits of anticholinergic use in schizophrenia: focusing on its effect on cognitive function. Psychiatry Clin Neurosci. 2014;68(1):37-49. doi:10.1111/pcn.12088 Quirce S, Domínguez-Ortega J, Barranco P. Anticholinergics for treatment of asthma. J Investig Allergol Clin Immunol. 2015;25(2):84-93. Annaházi A, Róka R, Rosztóczy A, Wittmann T. Role of antispasmodics in the treatment of irritable bowel syndrome. World J Gastroenterol. 2014;20(20):6031-43. doi:10.3748/wjg.v20.i20.6031 Howland RH. Potential adverse effects of discontinuing psychotropic drugs. Part 1: Adrenergic, cholinergic, and histamine drugs. J Psychosoc Nurs Ment Health Serv. 2010 Jun;48(6):11-4. doi:10.3928/02793695-20100506-01 Additional Reading Fox, C.; Smith, T.; Maidment, I. et al. "Effect of medications with anticholinergic properties on cognitive function, delirium, physical function and mortality: a systematic review". Age and Ageing. 2014; 43(5): 604-15. DOI: 10.1093/ageing/afu096.