Tasty Morsels of EM 080 – FRCEM Organophosphate Poisoning

26 Jul

I’m entering a few months prep for the UK and Ireland exit exam in Emergency Medicine: the FRCEM. I’ll be adding lots of little notes on pearls I’ve learned along the way. A lot of my revision is based around the Handbook of EM as a curriculum guide and review of contemporary, mainly UK guidelines. I also focus on the areas that I’m a bit sketchy on. With that in mind I hope they’re useful.

You can find more things on the FRCEM on this site here.

When is this used?

  • insecticides – widely used internationally in suicide but not in the UK
  • nerve gas agents
    • Tokyo Sarin was the most famous and these two reviews of the incident make fascinating reading

What is the mechanism of action?

  • inhibit cholinesterases leading to accumulation of acetylcholine at NM junctions

What are the clinical features?

  • Acute Cholinergic Toxicity (though bradycardia in organophosphates in particular is apparently rare)

by Brian Kloss Click for source

Describe the recommended managemen


  • atropine
    • 2mg (0.05mg/kg for a child) every 5 mins doubled each time (Toxbase)
    • goals are dry lungs, HR> 80, BP >80
  • pralidoxime (reactivates cholinesterase)
    • Toxbase says give it everyone who gets atropine
    • 2g (30mg/kg in a child) IV followed by an infusion
    • A combo pen with atropine and pralidoxime in it together is available
  • benzos for agitation and seziures


Of note this was covered before on this site in 2012 looking at mainly the pesticide version

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.