Last updated: September 20, 2023

Summarytoggle arrow icon

Poisoning occurs when a substance that is inhaled, ingested, or absorbed through the skin has harmful effects or even causes death. The type of poison, the amount taken, and the size and age of the individual involved are all factors that determine if a substance is actually harmful. Substances that are commonly thought to be harmless, such as water and most vitamins, can also be harmful if taken in excess. The focus of this article is poisoning from organophosphates, cyanide, ethylene glycol and methanol, laundry and cleaning products, mushrooms and plants, and carbon dioxide. In the United States, if poisoning is suspected, Poison Control (available 24/7 at 1-800-222-1222) should be contacted immediately to obtain information from specialists regarding management. If the poisonous substance is unknown, the patient's case history and clinical features may help determine the causative agent, which is important for the selection of a proper antidote (if available).

For more information on poisoning due to overdose of specific substances, see the respective articles, i.e., benzodiazepine overdose, anticholinergic poisoning, opioid overdose, beta blocker poisoning, salicylate poisoning, carbon monoxide poisoning, toxic alcohol poisoning, and metal poisoning. For intoxication with recreational drugs (e.g., cocaine, phencyclidine), see “Substance use disorders” and “Stimulant intoxication and withdrawal.”

Overviewtoggle arrow icon

Table of drugs/poisons and their specific antidotes/management [1][2][3]

Toxicity Antidote/management

Acetylcholinesterase inhibitors and organophosphates (e.g., parathion, E605)

Antimuscarinic/anticholinergic agents (e.g., atropine, medications with anticholinergic effects, jimson weed, deadly nightshade)

Beta blockers
Thrombolytic agents (e.g., recombinant tPA)
Tricyclic antidepressants


Carbon dioxide
  • Normal or high concentration oxygen depending on severity [4]
Carbon monoxide
  • 100% high-flow oxygen
  • Consider HBOT
Methanol, ethylene glycol (antifreeze)

Activated charcoal effectively binds acetaminophen, aspirin, and tricyclic antidepressants. It is ineffective in the treatment of heavy metal toxicity (e.g., mercury, lead), cyanide, lithium, acids, bases, and toxic alcohols such as methanol.

If further expert help is required: call Poison Control, available 24/7 at 1-800-222-1222 in the US.

Organophosphatestoggle arrow icon

Always use personal protective equipment (e.g., neoprene gloves, gown, charcoal cartridge mask) when decontaminating patients. Remove contaminated clothing and wash contaminated skin.

The greatest danger in organophosphate poisoning is respiratory failure.

The acronym “DUMBBELLSS” lists the clinical features of organophosphate poisoning → D = Diarrhea, U = Urination, M = Miosis, B = Bronchospasm / Bradycardia, E = Emesis, L = Lacrimation / Lethargy, S = Sweating / Salivation

Cyanidestoggle arrow icon

Induction of methemoglobinemia (e.g., with amyl nitrite or sodium nitrite) is contraindicated in patients with inhalation injury unless concomitant carbon monoxide toxicity has been excluded because of the risk of worsening tissue hypoxia.

Consider cyanide poisoning in a patient with chronic renal failure who has very recently undergone treatment for a hypertensive emergency and is now presenting with altered mental status and lactic acidosis.

Patients with a smoke inhalation injury should be treated empirically for cyanide toxicity.

Laundry and cleaning productstoggle arrow icon


Caustic agents

Do not induce vomiting, as this may cause further damage to the esophagus. Do not attempt to neutralize the alkali with a weak acid, as this may lead to vomiting or local heat production.

Mushrooms and plantstoggle arrow icon

Amanita phalloides (death cap mushroom)

Amanita muscaria (fly agaric mushroom)

Atropa belladonna (belladonna, deadly nightshade)

Features of anticholinergic syndrome can be remembered with "Blind as a bat (cycloplegia & mydriasis), mad as a hatter (delirium & hallucinations), red as a beet (cutaneous vasodilatation), hot as hell (hyperthermia), dry as a bone (anhidrosis & xerophthalmia), the bowel and bladder lose their tone (urinary retention & absent bowel sounds), and the heart runs alone (tachycardia).”

Carbon dioxide poisoningtoggle arrow icon

Nicotine poisoningtoggle arrow icon

Ingestion of cigarettes (nicotine)

Referencestoggle arrow icon

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