It would be really inconvenient if there were long-term effects, but I can deal if they're unavoidable.
He can swallow something; he can be bitten by something; he can breathe something; it doesn't matter, as long as I have the uncertainty and a period of understanding by the character of what's happening.
Yeah, I'm playing H/C Bingo. Yeah, my prompt is "Poisoning."
I've searched for information on neurotoxins - AFAICT, they act too quickly. I've looked at lists of poisons and antidotes - fascinating reading, but not really what I need. I've found info on immediate care (keep them breathing, call 9-1-1) but not on what happens at hospital; and I'm very squeamish when it comes to medical reading so I'm tossing in the towel and asking for help.