Drug Summary

Atropine Sulfate (as an antidote for poisoning)

Pharmacologic properties:

Atropine is a potent parasympatholytic anticholinergic. It inhibits muscarinic receptor activity in the parasympathetic sites on smooth muscle and the central nervous system, as well as cardiac and secretory tissue. This reduces vagal tone, increases automaticity of the SA node and increases AV conductions, thus increasing heart rate. Additional effects include drying secretions and slowing motility in the gastrointestinal tract.


  • Organophosphate Poisoning (i.e. parathion, malathion, rid-a-bug) and carbamate (Baygon, sevin, and many common roach and ant sprays)
  • Poisoning Signs “SLUDGE”
  • Salivation
  • Lacrimation
  • Urination
  • Defecation
  • GI hypermotility (Emesis, diarrhea)
  • Excessive sweating and bronchorrhea
  • Additional signs include: pinpoint pupils and bradycardia


  • None when used in the management of severe organophosphate poisoning


  • It is important that the patient be adequately oxygenated and ventilated prior to using atropine, as atropine may precipitate ventricular fibrillation in a poorly oxygenated patient.
  • Do not rely upon pupilloconstriction to discontinue or to titrate medications

Adverse Reactions:

  • Victims of organophosphate poisoning can tolerate large doses (1000 mg) of atropine.
  • Signs of atropinization (flushing, pupil dilation, dry mouth, tachycardia) are likely to occur

Dosage and administration:

  • Adult
    • 2 mg IV. May repeat 2 mg every 5 minutes
    • Titrate until respiratory secretions/ distress begins to decrease
  • Pediatric
    • 0.02 mg/kg repeat every 5 minutes as necessary
    • Titrate until respiratory secretions/ distress begins to decrease