Cholinergic and anticholinergic toxidromes
Posted by dkwinter

Cholinergic toxicity (DUMBBELSS)

Syndrome

  • Diarrhea
  • Urination
  • Miosis
  • Bronchospasm
  • Bradycardia
  • Excitation of skeletal muscle and CNS
  • Lacrimation
  • Sweating
  • Salivation

Direct cholinergic agonists

  • Bethanechol (activates bowel and bladder)
  • Carbachol (treats glaucoma; contracts pupils; decreases IOP)
  • Pilocarpine (activates sweat, tears, saliva)
  • Methacholine (asthma provocation)

Indirect cholinergic agonists (acetylcholinesterase inhibitors)

  • Neostigmine (postop and neurogenic ileus and urinary retention; treats myasthenia gravis; post-op reversal of NMJ blockage)
  • Pyridostigmine (treats myasthenia gravis; does not enter CNS)
  • Edrophonium (diagnosis of myasthenia gravis; extremely short acting)
  • Physostigmine (treats glaucoma; enters CNS; treats atropine overdose)
  • Echothiophate (treats glaucoma)
  • Organophosphates found in insecticides. Antidote is atropine to counteract the bradycardia plus pralidoxime, which regenerates AchE by removing the organophosphate.

Antidote

  • Pralidoxime (reactivates acetylcholinesterase that had been deactivated by phosphorylation)

 

Anticholinergic toxicity

Muscarinic cholinergic antagonists (c.f. ACh NMJ antagonists/paralytics)

  • Atropine, homatropine, tropicamide (produce mydriasis and cycloplegia)
  • Benztropine (enters CNS)
  • Scopolamine (enters CNS; treats motion sickness)
  • Ipratropium (treats asthma; COPD)
  • Oxybutynin, glycopyrrolate (reduces urgency in mild cystitis; reduces bladder spasms)
  • Methscopolamine, pirenzepine, propantheline (peptic ulcer treatment)

Other medications causing anticholinergic symptoms

  • Tricyclic antidepressants (imipramine ≈ amitriptyline > nortriptyline)

Syndrome

  • Hot as a hare
  • Dry as a bone
  • Red as a beet
  • Blind as a bat
  • Mad as a hatter

 

     Specifically

  • Hyperthermia due to decreased sweating (especially in infants)
  • Pupil dilation
  • Cycloplegia (loss of focus due to ciliary m paralysis)
  • Disorientation (via M1/CNS inhibition)
  • Acute angle-closure glaucoma
  • Urinary retension in men with prostatic hypertrophy
  • Decreased gastric acid secretion
  • Decreased bowel motility
  • Decreased urinary urgency

Antidote