Toxic Fungi of Western North America

by Thomas J. Duffy, MD

The clinical picture of muscarine poisoning

Muscarine activates the parasympathetic nervous system. Symptoms of sweating, salivation, nausea, teary eyes, small pupils and/or pupils sluggishly reacting to light, slow heart rate, increased urination and sometimes diarrhea occur within 20-30 minutes. Severe poisonings may produce more serious symptoms, including bronchial constriction, slow heart rate with faster “escape rhythms” and pulmonary edema. Tremors and dizziness apparently reflect diminished blood flow to the brain or mild activation of the glutamate hierarchical system. Muscarine itself passes only with difficulty into the brain. One Colorado case of Amanita muscaria poisoning appeared to cause muscarinic effects and excessive lactation in a nursing woman. (155),(40b) There are no reports of muscarine damage to the fetus. There is one case of a mild asthma attack. (91)