What are examples of anticholinergic (anticholinergic) medications?

Anticholinergic Medications List

Anticholinergic medications include ipratropium bromide, scopolamine, atropine, glycopyrrolate, benzhexol, and first-generation antihistamines like diphenhydramine and hydroxyzine. 1

Common Anticholinergic Medications by Class

Inhaled Anticholinergics

• Ipratropium bromide (Atrovent) - used for rhinorrhea in allergic and non-allergic rhinitis 1

Antimuscarinic Agents

• Scopolamine (transdermal patches) - used for motion sickness and vertigo 1
• Atropine - used for bradycardia and as premedication before anesthesia 1
• Glycopyrrolate - used for excessive secretions and preoperatively 1, 2
• Benzhexol hydrochloride - used for drooling in developmental disabilities 2
• Hyoscyamine - used for gastrointestinal spasms 1

Antihistamines with Strong Anticholinergic Properties

• Diphenhydramine (Benadryl) - 50% sedation potential 3
• Hydroxyzine (Atarax) - 80% sedation potential 3
• Promethazine (Phenergan) - 60-73% sedation potential 3

Medications with Secondary Anticholinergic Effects

1. Antidepressants

   • Tricyclic antidepressants (amitriptyline, imipramine, doxepin)
   • Some SSRIs (paroxetine has higher anticholinergic activity)

2. Antipsychotics

   • First-generation (chlorpromazine, thioridazine)
   • Some second-generation (olanzapine, clozapine)

3. Antiemetics

   • Prochlorperazine
   • Metoclopramide (lower anticholinergic activity)

4. Antispasmodics

   • Oxybutynin
   • Tolterodine
   • Solifenacin

5. Other Medications

   • Some antiparkinson drugs
   • Some antiepileptics
   • Some muscle relaxants

Clinical Effects of Anticholinergic Medications

Peripheral Effects

• Dry mouth (xerostomia)
• Blurred vision
• Urinary retention
• Constipation
• Reduced sweating
• Tachycardia
• Mydriasis (pupil dilation)

Central Effects

• Confusion
• Memory impairment
• Delirium
• Hallucinations
• Agitation
• Sedation
• Cognitive impairment 4, 5

Anticholinergic Burden and Risk Factors

The cumulative effect of taking multiple medications with anticholinergic properties creates an "anticholinergic burden" 4. This is particularly concerning in:

• Older adults
• Patients with pre-existing cognitive impairment
• Patients with mental illness
• Those taking multiple medications 6

Clinical Considerations

High-Risk Populations

• Elderly patients are particularly vulnerable to anticholinergic side effects and may experience increased risk of falls, cognitive decline, and functional impairment 3, 4
• Patients with dementia may experience worsening cognitive symptoms
• Patients with narrow-angle glaucoma may experience dangerous increases in intraocular pressure
• Patients with prostatic hypertrophy may experience urinary retention

Monitoring and Management

• Regular medication reviews to identify and reduce anticholinergic burden
• Consider alternatives with lower anticholinergic activity when possible
• Monitor for anticholinergic side effects, particularly in high-risk populations
• Deprescribe anticholinergic medications when appropriate 4, 5

Anticholinergic Toxicity Syndrome

Characterized by:

• Hyperthermia
• Mydriasis (dilated pupils)
• Dry, hot, flushed skin ("red as a beet, dry as a bone, hot as a hare, blind as a bat, mad as a hatter")
• Urinary retention
• Decreased bowel sounds
• Tachycardia
• Hypertension
• Altered mental status (confusion, agitation, hallucinations) 1

Practical Applications

Anticholinergic medications serve important therapeutic roles in:

• Managing rhinorrhea in allergic and non-allergic rhinitis 1
• Controlling vertigo in Ménière's disease 1
• Managing excessive secretions in palliative care 1
• Premedication before anesthesia 1
• Treating drooling in developmental disabilities 2

However, their use must be balanced against potential adverse effects, particularly in vulnerable populations. When prescribing these medications, always consider the patient's overall anticholinergic burden and monitor for adverse effects.