I was at a friends house and asked if he had a puffer. He passed me one, and I had four puffs. It wasn't until after that I checked the expiry date and noticed it expired four years ago. Am I going to die? Haha.
I doubt it if you're not already dead. If anything was toxic it'd be absorbed pretty quickly into your bloodstream and you'd notice the effects shortly afterwards. Pharmaceuticals generally undercut the expiration date because you're ingesting/injecting/inhaling something where they predict contamination over continued use. Since every time you take a puff of an inhaler, it temporarily breaks a seal in order to release gases into your respiratory system it can potentially allow other gases inside, changing the composition. So it's most likely that it's fine if it's unused/barely used because then the contents aren't likely to be contaminated. They're also not exposed to UV rays which can cause reactions (but not because it's in an inhaler). How long ago did you do this out of interest? Edit: Don't do it again either.
why would you use one when weed works better when you vaporized it, weed has saved 2 times when my lungs were closing due to severe allergic reaction, i grabbed my vape and it opened up my airways, did cause me to cough up gunk before they fully cleared