Here's a recent news item about a bunch of idiots in Perth, Australia who snorted hyoscine instead of the cocaine they thought it was. Major fail!
They found themselves in the emergency room exhibiting classical features of the atropine toxidrome - mad as Max, hot as a pot, dry as Mars, red as Sonja, and blind as Dare Devil.
Once a diagnosis is made, treatment is quite simple. Apart from respiratory support, overcome the atropine effects by administering physostigmine, an acetylcholinesterase inhibitor.
Here are short videos on :cholinergic neurotransmission