I suspect that most of the initial side effects can be blocked by atropine, possibly even diphenhydramine. Most of the side effects of nicotine are via the muscarinic receptors while what kills you is the nicotinic receptor interaction. Atropine keeps nicotine off of the muscarinic receptors but cannot prevent the muscle paralysis from a high dose. This stops breathing and I would assume the heart.
"Atropine has no effect on the nicotinic receptors and, therefore, has no
effect on the autonomic ganglia and neuromuscular junction. Therefore, muscle weak-
ness, fasciculations (twitching), tremors, and
paralysis associated with organophosphate, carba-
mate, and
nicotine poisoning are not indications for further atropine dosing.
It does
have a partial effect on the CNS and is helpful in resolving or preventing seizures."
Atropine would likely have to be acquired in the form of datura seeds, and this would also include the other tropane alkaloids. These plants are also notoriously difficult to dose, highly variable potency. There might be more helpful studies out there, Im not sure. Based on other studies using the wrong anticholinergic or just at the wrong dose could cause more side effects.
This could probably be tested by taking the atropine and then titrating up the nicotine dose in single milligrams at first.