Anticholinergic side effects

Anticholinergic side effects

Some anti-Parkinson, antivertigo, and incontinence agents depend on anticholinergic activity as the mechanism of drug action. However, as people age, the therapeutic range for these agents becomes smaller, exposing elderly patients to a greater risk of toxicity. Also remember that many drugs with other primary mechanisms of action have significant anticholinergics effects. Thus, if an older patient is taking one or more of these agents, toxicity can also occur.



Drugs that can cause anticholinergic side effects are shown below:

  • Antidepressants: amitriptyline, imipramine, paroxetine
  • Antihistamines: diphenhydramine, chlorpheniramine
  • Antivertigo: betahistine, scopalamine, meclizine
  • Antiemetics: prochlorperazine, promethazine, hydroxyzine
  • Antispasmotics: clidinium, dicyclomine, hyoscyamine
  • Muscle relaxants: cyclobenzprine, orphenadrine
  • Urinary antispasmotics: oxybutynin
  • Mydriatics: atropine, homotropine, tropicamine
  • Antiparkinson agents: benztropine, trihexyphenidyl
  • Antidiarrheals: diphenoxylate-atropine
  • Antipsychotics: chlorpromazine, thioridazine, clozapine

Which of the following scenarios can lead to anticholinergic delirium? An elderly patient with:


Besides delirium, arrhythmias and seizures, other anticholinergic effects include: