Types of mushroom poisoning and actions of arecoline
THE CONTEXT
Mushroom poisoning differs by toxic principle, timing, predominant manifestations and treatment.
Early muscarine-type poisoning
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Inocybe and related species cause characteristic muscarinic symptoms within an hour of ingestion.
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Atropine promptly reverses these symptoms.
Hallucinogenic poisoning
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Muscimol and other isoxazole compounds occur in Amanita muscaria and related mushrooms in much larger quantities than muscarine.
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These compounds activate amino acid receptors and block muscarinic receptors in the brain; manifestations are primarily central.
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There is no specific treatment, and atropine is contraindicated.
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Psilocybe mexicana is another hallucinogenic mushroom. Its active principle, psilocybine, is a tryptaminergic compound related to 5-hydroxytryptamine.
Late phalloidin-type poisoning
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Peptide toxins in Amanita phalloides, Galerina and related species inhibit RNA and protein synthesis.
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Symptoms begin after many hours and reflect damage to the gastrointestinal mucosa, liver and kidney.
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Treatment consists of supportive measures; thioctic acid may have some antidotal effect.
Arecoline
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Arecoline occurs in betel nut and has both muscarinic and nicotinic actions, including actions at skeletal muscle endplates.
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It has prominent central nervous system effects. Trials as a cognitive enhancer in dementia did not establish usefulness, and it has no therapeutic use.