• Clinical science
  • Clinician



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 monoxide 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 drugs, metals, and food poisoning, see the respective articles, i.e., benzodiazepine overdose, anticholinergic poisoning, opioid intoxication, beta blocker poisoning, salicylate toxicity, carbon monoxide poisoning, and metal toxicity. For intoxication with recreational drugs (e.g., cocaine, phencyclidine), see the article on substance use disorders.


Table of drugs/poisons and their specific antidotes/management

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)

  • Sodium bicarbonate
Beta blockers
Thrombolytic agents (e.g., recombinant tPA)
  • Catalyze conversion of plasminogen to plasmin → excessive bleeding
Tricyclic antidepressants


Carbon dioxide
  • Normal or high concentration oxygen depending on severity [1]
Carbon monoxide
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.



Primarily used as insecticides, herbicides, and nerve agents

Example: parathion or E605

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



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.


Ethylene glycol, methanol and isopropyl alcohol

Ethylene glycol


  • Sources of exposure
    • Fuels (highly flammable)
    • Ingested as ethanol substitute by alcoholics
    • Improper distillation of spirits
    • Self-harm attempts
    • Accidental ingestion
  • Effects
  • Features

Isopropyl alcohol

Management of ethylene glycol, methanol, and isopropyl alcohol poisoning

Always consider simultaneous intoxication with more than one substance and adjust the management plan accordingly.


Laundry and cleaning products


  • Brief description: surfactants used as cleaning agents (e.g., laundry or dish detergents)
  • Clinical features
  • Management
    • Secure airways, oxygenation, monitoring, fluid resuscitation
    • Endoscopy to evaluate severity of injury
    • Perform ABG to evaluate for pH
    • Anti-foaming agent: polydimethylsiloxane (dimethicone)

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 plants

Amanita phalloides (death cap 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 poisoning

  • Properties: colorless, odorless gas
  • Exposure: increased production during fermentation processes, e.g., in grain silos, wells, cesspools
  • Clinical features
    • In atmospheric concentrations < 0.3%: no health risks
    • In atmospheric concentrations of 5–8%: headaches, vertigo, dyspnea and tachypnea, tachycardia and arrhythmias, impaired consciousness
    • In atmospheric concentrations > 8%: tremors, sweating, diminished hearing, loss of consciousness, respiratory depression, respiratory arrest
  • Management



Ingestion of cigarettes (nicotine)

  • Exposure: accidental ingestion (usually toddlers)
  • Clinical features
    • Vomiting, pallor, tachycardia, perspiration
    • Following ingestion of large amounts: (↓ blood pressure, heart rate), respiratory failure)
  • Treatment: activated charcoal up to 60 minutes after ingestion

Ingestion of button batteries

  • Exposure: accidental ingestion (usually toddlers)
  • Pathophysiology: : Button batteries lodged in the moist environment of the esophagus can result in an electrolysis reaction, leading to corrosion and tissue necrosis; serious burns may result within 2 hours of ingestion.
  • Clinical features
  • Diagnostics
    • X-ray to determine location and confirm diagnosis
    • Button batteries can be differentiated from a coin by the battery's halo/double-rim effect on AP view (i.e., within the radiopaque density of the battery, a parallel line can be seen).
    • On lateral view, button batteries show a “step-off” effect due to the different size of the negative (smaller) and positive pole
  • Management
    • Dependent upon patient age, size of battery, and suspected location of battery
    • Immediate endoscopic removal indicated if:
      • Battery is located in the esophagus.
      • Battery is located in the stomach or lower in the digestive tract and a magnet was co-ingested.
  • Complications

Always consider the possibility that a button battery has been ingested if the parents think that their child has ingested a coin or another foreign object.