A List of Anticholinergics

A group of prescription medications that block acetylcholine

Prescription medication from pharmacy

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Anticholinergics are a group of prescription medications that block acetylcholine, a brain hormone (neurotransmitter) that plays a vital role in smooth, cardiac, and skeletal muscle contractions as well as mental functions such as memory, REM sleep, attention, learning, and cognition.

Anticholinergics block acetylcholine at the receptors, but because they block a wide variety of receptors in the brain, this class of medication can also elicit many different side effects.

Anticholinergics help with slowing the gut down, thereby causing relief from diarrhea. They also allow the bladder to relax, thereby helping with urinary incontinence.

What Anticholinergics Are Used For

Anticholinergics are used to treat various medical conditions including:

List of Anticholinergics

  • Atropine: Used to treat organophosphate or nerve gas poisoning
  • Belladonna alkaloids: Combination of acetycholine and phenobarbital used to relieve stomach cramping associated with irritable bowel syndrome and spastic colon
  • Benztropine mesylate: Used to treat symptoms of Parkinson’s disease as well as extrapyramidal side effects from anti-psychotics
  • Clidinium: Combined with the benzodiazepine chlordiazepoxide to help treat stomach ulcers and irritable bowel syndrome
  • Cyclopentolate: Used in eyed examinations to dilate the pupil
  • Darifenacin: Relaxes the muscles in the bladder to treat overactive bladders
  • Dicylomine: Works by slowing the natural movements in the gut to help relive irritable bowel syndrome
  • Fesoterodine: Used to treat symptoms of an overactive bladder 
  • Flavoxate: Used to treat bladder symptoms such as frequent urination, urgent urination, increased nighttime urination, bladder pain, and leakage
  • Glycopyrrolate: Helps to control conditions that involve excessive stomach acid production such as peptic ulcer disease. The injectable form of glycopyrrolate is also used to reduce saliva, nasal, lung, and stomach secretions and to help control heart rate during surgery.
  • Homatropine hydrobromide: Works by dilating the pupil of the eye to treat inflammatory conditions such as uveitis
  • Hyoscyamine: Works by reducing stomach acid production, slowing down the natural movements of the gut, and relaxing muscles in the stomach, gallbladder, kidneys, and intestines. It also reduces the production of certain body fluids such as saliva and sweat. 
  • Ipratropium: Works by relaxing and opening the air passages (bronchodilates) and is used to prevent wheezing, shortness of breath, coughing, and chest tightness in individuals with chronic obstructive pulmonary disease (COPD).
  • Orphenadrine: Relaxes skeletal muscles to help relieve muscle spasms and pain
  • Oxybutynin: Relaxes the bladder and used to treat symptoms of overactive bladder
  • Propantheline: Used for the treatment of excessive sweating (hyperhidrosis), cramps or spasms of the stomach, intestines, or bladder, and involuntary urination
  • Scopolamine: Used to treat motion sickness and postoperative nausea and vomiting.
  • Solifenacin: Used to treat neurogenic detrusor overactivity (a bladder control condition caused by the brain, spinal cord, or nerve problem)
  • Tiotropium: Works by relaxing and opening the air passages (bronchodilates) and is used to prevent wheezing, shortness of breath, coughing, and chest tightness in individuals with chronic obstructive pulmonary disease (COPD)
  • Tolterodine: Used to treat frequent urination, urinary incontinence, or urinary urgency
  • Trihexyphenidyl: Used to treat the symptoms of Parkinson's disease and to control extrapyramidal symptoms
  • Trospium: Helps to relax the muscles in the bladder and reduce the daily episodes of incontinence and used to treat the symptoms of an overactive bladder, such as a frequent need to urinate or incontinence (loss of bladder control)

Side Effects of Anticholinergics

Like many prescription medications, anticholinergics are known to have some side effects, especially in the elderly population.

When taken with antidepressants or antihistamines, side effects are more common and pronounced. Even if taken as directed, side effects can occur and include the following:

  • Dry mouth
  • Sore throat
  • The inability to sweat
  • Blurry vision
  • Confusion
  • Hallucinations
  • Inability to concentrate
  • Dizziness
  • Increased body temperature
  • Constipation
  • Dry eyes
  • Urinary retention (unable to urinate)

Anticholinergic Toxicity

It is difficult to understand anticholinergics without understanding anticholinergic toxicity, which occurs when an individual ingests more than the prescribed amount of anticholinergic medication.

Anticholinergic Syndrome

Anticholinergic syndrome (ACS), commonly known as anticholinergic toxicity most commonly occurs due to intentional overdose, accidental ingestion, taking the wrong dose at the wrong time (medical noncompliance), or in elderly individuals when they have too many prescriptions to keep up with (polypharmacy).

Anticholinergic Toxidrome

There is a common anticholinergic toxidrome that represents the most common symptoms associated with anticholinergic toxicity (anticholinergic syndrome):

  • “Hot as a desert”: Hyperthermia (dangerous increase in body temperature)
  • “Blind as a bat”: Blurry vision
  • “Mad as a hatter”: Confusion
  • “Dry as a bone”: Urinary retention and dry mouth
  • “Red as a beet”: Flushed skin

Individuals with severe poisoning can present with the above warning signs in addition to loss of consciousness, severe psychosis, cardiac complications and impaired breathing. The individual should be rushed to the hospital and life saving measures should be started immediately.

Physostigmine is the antidote of choice for anticholinergic toxicity and should be administered as soon as possible but with extreme caution as giving too much physostigmine can lead to acetylcholine toxicity (cholinergic poisoning).

What to Do If You Experience Side Effects

As with any prescription or over the counter medication, it is important to follow specific directions on the box or from your healthcare provider and take as directed.

If you are taking your anticholinergic as directed but are experiencing side effects that are affecting your daily life, it is important to discuss this with your healthcare provider.

By weighing the pros and cons of the anticholinergic side effect, your healthcare provider can find the right medication and dosage by which to deliver treatment without the burden of side effects. Sometimes minimal side effects can be tolerated in order for you to receive the best treatment.

Your healthcare provider may choose to decrease the dosage of your current anticholinergic, switch to a different anticholinergic (some specific anticholinergics have a higher likelihood of side effects than others), or stop the medication and switch you to a different class of drugs to treat your disorder.

It is important to not discontinue your anticholinergics or any other prescription medication without first speaking to your provider. There are some prescription medications that must be slowly tapered off in order to prevent dangerous withdrawal effects.

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