Final answer:
The muscarinic blocker used for motion sickness prevention and treatment is scopolamine, typically applied via a transdermal patch. Scopolamine is safe at controlled doses despite its notorious reputation. Alternatives include antihistamines such as dimenhydrinate.
Step-by-step explanation:
The muscarinic blocker used in the prevention and treatment of motion sickness is scopolamine. Scopolamine is derived from the Atropa genus, which includes deadly nightshade. It is effective in treating motion sickness through its transdermal patch form, which ensures that the drug is administered in a controlled, low concentration to prevent the potential dangers of higher doses. Despite concerns over being labeled "The Most Dangerous Drug," scopolamine patches are considered a safe and popular option. However, for those who are hesitant to use scopolamine, an alternative can be antihistamines like dimenhydrinate (Dramamine®).
Atropine, another muscarinic antagonist from the Atropa genus, is used to manage the symptoms of nerve agent poisoning. While atropine does not pass the blood-brain barrier as effectively as some synthetic anticholinergics, it is an antagonist to muscarinic acetylcholine receptors, which makes it useful in the treatment of anticholinergic symptoms.