The Side Effects of Anticholinergic Medications

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Certain medications cause specific side effects due to their anticholinergic effect within the body. These include some antidepressants, antispasmodics, and antipsychotic medications. Take a look at both the upside and downside of anticholinergic side effects.

What Are Anticholinergic Effects?

Anticholinergic effects are changes that occur in your body when you take in a substance that prevents acetylcholine from acting as a neurotransmitter, This leads to decreased parasympathetic activity in the body, which produces several different symptoms.

The neurotransmitter acetylcholine is involved in many major bodily functions. It is involved with muscle functioning, but it also plays an important role in how the brain functions, and to a lesser extent how the heart functions. Because of this, substances that act in an anticholinergic manner will result in effects that are experienced throughout the body. These substances include certain medications, plant toxins, and pesticides.

Medications Chosen for Their Anticholinergic Effects

In some cases, medications are specifically prescribed to take advantage of their anticholinergic effects. An example of this would be the use of antidepressants and antispasmodics in the treatment of irritable bowel syndrome (IBS), particularly in cases where the predominant symptom is diarrhea. The anticholinergic effect of certain antidepressants or antispasmodic medications of slowing down the movement of the digestive system is desirable in order to reduce the frequency of diarrhea episodes.

The effects are also beneficial for COPD and asthma to improve breathing, and for Parkinson's disease to reduce tremors.

Common Anticholinergic Side Effects

You may experience side effects when taking medications with anticholinergic properties. Some are only temporary and diminish as you adjust to the medication.

But sometimes they can be more severe and debilitating. Older people appear to have more risk of significant side effects. Most concerning is emerging research that anticholinergic medication may raise the risk of dementia in older people.

  • Blurred vision
  • Constipation
  • Decreased sweating
  • Dizziness
  • Dry mouth
  • Difficulty urinating and/or kidney failure

Other less common side effects include:

  • Bowel obstruction
  • Cognitive impairment
  • Dilated pupils
  • Increased heart rate

Severe side effects can occur in rare cases. If you are experiencing any side effects that are alarming to you, seek medical attention immediately.

What Medications Are Most Likely to Cause Anticholinergic Side Effects?

Anticholinergic side effects are most often experienced by people who are taking certain antispasmodic medicationstricyclic antidepressants, and antipsychotic medications. Other medications that may have anticholinergic effects include medications for Parkinson's disease, some antihistamines, and some heart medications. Here are some of the more commonly used medications that have anticholinergic effects.

Antidepressants with Anticholinergic Effects:

Antispasmodics with Anticholinergic Effects:

Antipsychotic Medications with Anticholinergic Effects:

What to Do About Anticholinergic Side Effects

If you are experiencing side effects from your medication, speak with your doctor. Your health care provider can assess the degree of severity of your symptoms and make a decision as to whether to decrease your dosage or take you off the medication altogether. (Do not discontinue any medication without first speaking with your physician.) Another option for your physician is to switch out any of your other medications that might have anticholinergic effects so as to minimize any compounding effect.

If your side effect symptoms are mild, you may be able to minimize your discomfort by drinking plenty of water. To reduce the likelihood of constipation, be sure that you are eating foods that are high in dietary fiber.


Grey S, Hanlon J. "Anticholinergic medication use and dementia: latest evidence and clinical implicationsTherapeutic Advances in Drug Safety 2016 7: 217–224.

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