Atropine

Liverpool Hospital Emergency Department

Indications: 

  • Cholinergic Toxidrome (organophosphates / nerve agents / carbamates)
  • Toxin related bradycardia (temporising) 
  • Increasing heart rate in the case of drug induced torsades de pointes with prolonged  QT (temporising measure will require further chronotropy – adrenaline or  isoprenaline) 

Formulation: 

  • 600mcg ampoule
  • 1200mcg ampoule (1.2mg) 

Dosage and Administration 

Cholinergic Toxidrome:  

  • 1.2mg (paediatric 50mcg/kg up to 1.2mg) IV bolus. Double dose every 5  minutes until end points are reached. High doses may be needed
  • End points – clear chest / HR >80 BPM / SBP >80mmHg
  • Follow with atropine infusion 10-20% of loading dose / hr
  • 60mg atropine in a 50mL syringe (50 x 1.2mg ampoules).
  • Generally, 0.5 – 5mg/hr 

Chronotropy to increase HR in bradycardia or TdP 

  • 600mcg (20mcg/kg) bolus up to a maximum of 3mg 

Side Effects: 

Anticholinergic Toxidrome:

  • Confusion 
  • Pyrexia 
  • Ileus 
  • Tachycardia 
  • Urinary  retention 
  • Dry skin & mucous membranes 
  • Mydriasis 

Pit Falls: 

  • May require very large doses of atropine for cholinergic overdose (requiring stocks  from elsewhere)
  • Failure to administer enough atropine in cholinergic overdose