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
  • 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)
  • 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
  • Always have atropine at the bedside for bradycardia or cholinergic excess</ref>
  • 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.