dasMuscarin

dasMuscarin, more commonly known as muscarine in English, is a naturally occurring alkaloid that acts as a potent muscarinic acetylcholine receptor agonist. In German-language sources it may be referred to as das Muscarin. Muscarine was first isolated from Amanita muscaria and related mushrooms in the 19th century. It is found in several mushroom species, including Amanita muscaria, Amanita pantherina, and some Inocybe and Clitocybe species.

Chemistry and pharmacology: Muscarine is a quaternary ammonium compound that does not readily cross lipid membranes, so peripheral effects predominate and central nervous system penetration is limited. It activates muscarinic receptors (M1–M5), producing parasympathetic-like stimulation, and does not significantly stimulate nicotinic receptors.

Clinical effects: Ingested muscarine induces a cholinergic syndrome characterized by sweating, salivation, lacrimation, increased bronchial secretions, constricted pupils (miosis), bradycardia, hypotension, abdominal cramps, diarrhea, and urination. Onset typically occurs within 15 to 60 minutes after exposure. CNS effects are usually mild due to poor brain penetration, though severe poisoning can cause collapse in rare cases.

Diagnosis and treatment: Diagnosis is based on history and clinical presentation following mushroom exposure. Treatment focuses on symptomatic and supportive care, with atropine as the primary antidote to counteract muscarinic effects. Activated charcoal may be used if the patient presents early, and intravenous fluids support hemodynamic stability. There is no specific antidote beyond atropine, and management may require repeated dosing in severe cases.

Occurrence and notes: Muscarine is not responsible for the hallucinogenic effects associated with some Amanita mushrooms, which are due to other compounds such as ibotenic acid and muscimol. Muscarine toxicity is typically nonlethal with prompt supportive care.