Mushroom Toxicity Medication

Updated: May 12, 2022
  • Author: B Zane Horowitz, MD, FACMT; Chief Editor: Sage W Wiener, MD  more...
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Medication Summary

The goals of pharmacotherapy are to neutralize the toxin, to reduce morbidity, and to prevent complications. Drugs used include anticonvulsants, antiemetics, gastrointestinal (GI) decontaminants, antidotes, and anticholinergic agents.


Anticonvulsants, Other

Class Summary

These agents prevent seizure recurrence and terminate clinical and electrical seizure activity.

Lorazepam (Ativan)

Lorazepam is a sedative hypnotic with a short time to onset of effects and a relatively long half-life. By increasing the action of gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the brain, it may depress all levels of the central nervous system (CNS), including the limbic system and the reticular formation. Monitor the patient's blood pressure after administering a dose, and adjust as necessary.

Diazepam (Valium, Diastat)

Diazepam depresses all levels of the CNS (eg, the limbic system and the reticular formation), possibly by increasing GABA activity.


Phenobarbital interferes with the transmission of impulses from the thalamus to the cerebral cortex.


Antiemetic Agents

Class Summary

These agents block the dopamine receptors in the chemoreceptor trigger zone.

Prochlorperazine (Compazine)

Prochlorperazine may relieve nausea and vomiting by blocking postsynaptic mesolimbic dopamine receptors through anticholinergic effects and depressing the reticular activating system. It is not recommended in children weighing less than 20 lb (9.1 kg), because of the high incidence of extrapyramidal effects.

Metoclopramide (Reglan, Metozolv)

Metoclopramide works as an antiemetic by blocking dopamine receptors in the chemoreceptor trigger zone of the CNS.


Gastrointestinal Agents, Other

Class Summary

These agents are empirically used to minimize systemic absorption of the toxin.

Activated charcoal (Charcoal Plus, CharcoCaps, EZ-Char)

Activated charcoal is given as emergency treatment in poisoning caused by drugs and chemicals. The network of pores present in activated charcoal absorbs 100-1000 mg of drug for every 1 g of charcoal. Charcoal does not dissolve in water.

For maximum effect, administer activated charcoal within 30 minutes after ingestion of the poison. The first dose is generally given with a cathartic (eg, sorbitol 1 g/kg PO). Additional doses of sorbitol are not administered to children, because they can cause excessive intraintestinal osmotic shifts, electrolyte imbalance, and intravascular volume depletion.

Polyethylene glycol (MiraLAX, Dulcolax Balance)

Polyethylene glycol is a laxative with strong electrolyte and osmotic effects that has cathartic actions in the GI tract.



Class Summary

Most amatoxin antidotes are experimental, and their use is based on animal studies, anecdotal reports of success in humans, or both.

In addition to the medications listed below, silibinin is made of silymarin, an extract of the milk thistle plant Silybum marianum, and may act as a free radical scavenger or may interrupt enterohepatic circulation. It blocks amanitin uptake by hepatocytes. Silibinin is available in Europe but not in the United States.

Pyridoxine (Nestrex)

Fomepizole is a Cortinarius antidote that has a better safety profile than ethanol and is easier to dose and administer. In contrast to ethanol, levels need not be monitored during therapy.

Penicillin G (Pfizerpen)

Penicillin G is an antibiotic that may work as an antidote by blocking amanitin uptake by hepatocytes and preventing amanitin from binding to RNA polymerase. It interferes with synthesis of cell-wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms.

N-acetylcysteine (Acetadote)

N-acetylcysteine may provide a substrate for conjugation with a toxic metabolite.

Methylene blue

In reduced form, leukomethylene blue acts as an electron donor to reduce methemoglobin. Reduction of methylene blue is by nicotinamide adenine dinucleotide phosphate (NADPH) generated by glucose-6-phosphodiesterase (G-6-PD). The US Food and Drug Administration (FDA) warns against concurrent use of methylene blue with serotonergic psychiatric drugs, unless it is indicated for life-threatening or urgent conditions. Methylene blue may increase serotonin CNS levels, increasing the risk of serotonin syndrome.

Fomepizole (Antizol)

Fomepizole is an antidote that has a better safety profile than ethanol and is easier to dose and administer. In contrast to ethanol, levels need not be monitored during therapy.


Anticholinergic Agents

Class Summary

Atropine is a competitive inhibitor of acetylcholine and muscarine in the autonomic nervous system and relieves muscarinic effects, especially bronchorrhea. Inhaled anticholinergic agents (eg, ipratropium) may also be considered.


Administered IV/IM, atropine acts at parasympathetic receptor sites to block the actions of acetylcholine and muscarine.

Ipratropium (Atrovent)

Ipratropium is chemically related to atropine. It has antisecretory properties and, when applied locally, inhibits secretions from serous and seromucous glands lining the nasal mucosa.