Medication Summary
The goals of pharmacotherapy are to reduce morbidity, to prevent complications, and to neutralize the mushroom toxin (ibotenic acid, muscimol, psilocybin, or psilocin). Agents used include gastrointestinal (GI) decontaminants and benzodiazepines.
GI decontaminants
Class Summary
Activated charcoal is preferred when GI decontamination is desired.
Activated charcoal (Liqui-Char)
Activated charcoal is most useful if administered within 2 hours of ingestion. Outcome data are limited, especially when the agent is given more than 1 hour after ingestion. Administration of charcoal by itself (in aqueous solution), as opposed to coadministration with a cathartic, is the current practice standard for the following reasons:
• No studies have shown benefit from cathartics in this setting
• Whereas most drugs and toxins are adsorbed within 30-90 minutes, laxatives take hours to work
• Dangerous fluid and electrolyte shifts have occurred when cathartics are used in small children
When the ingested dose is known, charcoal may be given at 10 times the ingested dose in either 1 or 2 doses. For maximum effect, administer within 30 minutes of poison ingestion.
Benzodiazepines
Class Summary
Benzodiazepines are first-line agents for preventing seizure recurrence and terminating clinical and electrical seizure activity in patients with toxicity. They are also helpful in sedating patients with extreme agitation.
Diazepam (Valium)
Diazepam depresses all levels of the central nervous system (CNS), including the limbic system and the reticular formation, possibly by increasing the activity of gamma-aminobutyric acid (GABA). To avoid adverse effects, individualize the dosage and increase it cautiously.
Lorazepam (Ativan)
Lorazepam is useful for agitation or seizures and is the drug of choice for treatment of status epilepticus (because it persists in the CNS longer than diazepam does). By increasing the action of GABA (a major inhibitory neurotransmitter in the brain), it may depress all levels of the CNS, including the limbic system and the reticular formation. The rate of injection should not exceed 2 mg/min. Lorazepam may be administered intramuscularly (IM) if vascular access cannot be obtained.
Midazolam (Versed)
Midazolam is used as an alternative for terminating refractory status epilepticus. Because it is water-soluble, it takes approximately 3 times longer to achieve peak electroencephalographic (EEG) effects than diazepam does. Thus, the clinician must wait 2-3 minutes to evaluate its sedative effects fully before initiating a procedure or repeating the dose. Midazolam has twice the affinity for benzodiazepine receptors that diazepam does. It may be administered IM if vascular access cannot be obtained.
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Fly agaric (Amanita muscaria).
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Amanita pantherina.
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Amanita muscaria.
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Amanita muscaria var. guessowii with yellow cap surface, from Massachusetts.
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Amanita muscaria var. formosa sensu Thiers, from Oregon.
