Final answer:
The best acetylcholinesterase inhibitor to antagonize a block with 90% twitch suppression is neostigmine. It, among other inhibitors, enhances muscle contractions by preventing acetylcholine breakdown at synapses, which is useful in neuromuscular blockade and certain poisonings.
Step-by-step explanation:
The student asked which is the best acetylcholinesterase inhibitor to antagonize a block with 90% twitch suppression. The answer is neostigmine. This drug, along with others like edrophonium, pyridostigmine, and physostigmine, acts by inhibiting the enzyme acetylcholinesterase. This inhibition prevents the breakdown of acetylcholine at synapses, which is both a target for certain insecticides and a treatment strategy for conditions like Alzheimer's and myasthenia gravis. Increased acetylcholine in the synapses leads to enhanced muscle contractions, opposing the action of neuromuscular blocking agents by outcompeting them at the neuromuscular junction. In the context of atropine poisoning, a muscarinic agonist would be considered an antidote because atropine is an anticholinergic drug that blocks muscarinic receptors.