Template:Anticholinergic Toxicity Treatement

Treatment

  • Consider GI decon with Activated Charcoal if patient presents <2 hours after ingestion and remains cooperative

Sedation

  • Decreases the risk of hyperthermia, rhabdo, traumatic injuries
  • Benzos are agents of choice especially increase seizure threshold[1]
    • Repeat boluses every 5-15 minutes as needed to halt seizures and provide adequate sedation
    • Goal: QRS duration < 110 msec

Cholinesterase inhibition

  • Indicated for severe agitation or delirium (esp if unresponsive to benzos)
  • Contraindicated in QRS>100 or Na blockade signs (R' in aVR) and in narrow angle glaucoma
  • Relatively contraindicated in asthma or ileus
  • Physostigmine - strongly consider poison control consult before giving
    • Crosses blood brain barrier, can be used to help make dx
    • Dosing: 0.5mg-1mg IV over 5min (repeat dosing up to 2mg in first hour)[2]
    • Onset of action: 5-10min
    • If partial response, repeat x3
    • If 3 or more administrations are needed over a 6-hour period, start IV infusion (bolus 1-2 mg followed by 1 mg/hour)
    • Stop infusion every 12 hours to determine resolution of the toxidrome
    • Side effects: bradycardia, dysrhythmias, cholinergic excess[3]
    • Always have atropine at the bedside for bradycardia or cholinergic excess</ref>[4]
    • Contraindicated in TCA toxicity (associated with cardiac arrest) and in the presence of bradycardia or AV block

Other therapies

  • Sodium bicarbonate for conduction abnormalities (QRS prolongation)
    • 2 mEq/kg bolus (typically 2-3 amps of bicarb)
    • Begin continuous NaCO3 infusion at 250mL/hr if bolus effective
    • Solution preparation = 1L D5W mixed with 3 ampules NaHCO3
  • Burns MJ, et al. A comparison of physostigmine and benzodiazepines for the treatment of anticholinergic poisoning. Ann Emerg Med. 2000:35(4):374-381.
  • Rosenbaum C and Bird SB. Timing and frequency for physostigmine redosing for antimuscarininc toxicity. J Med Toxicol. 2010;6:386-92.
  • Pentel P and Peterson CD. Aystole complicating physostigmine treatment of tricyclic antidepressant overdose. Ann Emerg Med. 1980 Nov;9(11):588-90.
  • Nguyen TT, et al. Adverse events from physostigmine: an observational study. Am J Emerg Med. 2018;36:141-2.