TX

• Physiological effects of poison

  • Opposite effects as that of poison
• Chemical effects of poison


  • Changes the chemical nature of poison
• Mechanical effects of poison

  • Prevent absorption of poison
• YELLOW (Skin discoloration)


  • Picric acid
  • Nitric acid
• Poisoning


  Contact with a substance that results in toxicity
• Toxicity


  May result from exposure to excess amounts of normally nontoxic substances or substances that are poisonous at all doses
• Excessive water intake


  • Causes dilutional hyponatremia (water intoxication)
• Poisoning


  Commonly due to ingestion but can result from injection, inhalation, or exposure of body surfaces (Skin, eye, mucous membranes)
• Signs


  Objective; perceived by the doctor; ex: joint tenderness (lab values: bilirubin levels, etc)
• Symptoms


  Subjective; perceived by the patient; ex: pain, headache, vomiting
• Fever can both be a sign and a symptom
• Symptoms and signs vary depending on the substance. Different patients poisoned with the same substance may present with very different symptoms due to genetic polymorphism
• Toxidromes


  Collection of signs/symptoms that points to a certain illness; similar with syndrome
• Toxidromes


  • Anticholinergic
  • Sympathomimetic
  • Cholinergic
  • Opioid
  • Sedative-hypnotic
  • Serotonin toxicity
  • Sympatholytics
• Clinical strategy for treatment of the poisoned patient

  1. Stabilization of the patient

  2. Clinical evaluation (history, physical, laboratory and radiology)

  3. Prevention of further toxin absorption

  4. Enhancement of toxin elimination

  5. Administration of antidote

  6. Supportive care and clinical follow-up
• ABCDE mnemonic


  • A = Airway: Maintain patency
  • B = Breathing: Maintain adequate oxygenation and ventilation
  • C = Circulation: Maintain perfusion of vital organs
  • D = Disability: Assess for CNS dysfunction
  • E = Exposure: Assess "toxidrome"
• In severe cases, endotracheal intubation, mechanical ventilation, pharmacological blood pressure support, or extracorporeal circulatory support may be necessary and appropriate
• Laboratory evaluation

  Predictive relationships of drug plasma concentration (of toxicant) and clinical outcome and/or suggested concentrations that require therapeutic interventions
• If patient ingested a large amount of toxicant they should also be given large amount of antidote
• Radiographic examination


  • Plain radiographs can detect a significant amount of ingested oral medication containing ferrous or potassium salts
  • Chest and abdominal radiographs
  • Lead paint ingestion in childrenIngestion of halogenated hydrocarbons (carbon tetrachloride, chloroform)
  • Computed topography (CT) study of the head
• Prevention of further poison absorption

  • Minimizing the total amount that reaches the systemic circulation (oral, inhalational, topical route)
  • Removing the patient from the environment where the toxin is found & providing adequate ventilation and oxygenation (inhalational route)
  • Induction of emesis
  • Gastric lavage
  • Oral administration of activated charcoal
  • Whole bowel irrigation (enema)
• Enhancement of poison elimination

  • Alkalinization of the urine "ion trapping" (clearance of weak acids)
  • Hemodialysis
  • Hemoperfusion
  • Hemofiltration
  • Plasma exchange or exchange transfusion
  • Serial oral activated charcoal (MDAC-multiple-dose Activated Charcoal)
• Agents for which hemodialysis has been shown effective as treatment modality for poisoning

  • Meprobamate
  • Metformin
  • Paraldehyde
  • Phenobarbital
  • Alcohols
  • Antibiotics
  • Boric Acid
  • Bromide
  • Calcium
  • Potassium
  • Chloral hydrates
  • Salicylates
  • Fluorides
• Spray painting, foundry work, mining and extracting lead, battery manufacturing are occupational sources of poisoning
• Paint dust and flakes, automotive, and urban sources are non-occupational sources of poisoning
• Plasma exchange or exchange transfusion

  1. Removal of plasma and placement with frozen donor plasma, albumin, or both with intravenous fluid

  2. Complications include allergic-type reactions, infectious complications, and hypotension

  3. Replacement of a patient's blood volume with donor blood (neonate premature infant)
• Serial oral activated charcoal (MDAC-multiple-dose Activated Charcoal)


  1. Increase the systemic clearance of various drug substances

  2. Serves as a "sink" for the toxin

  3. Works by interrupting the enteroenteric-enterohepatic circulation of drugs
• Sources of occupational exposure

  • Spray painting
  • Foundry work
  • Mining and extracting lead
  • Batory manufacturing
• Sources of nonoccupational exposure

  • Paint dust and flakes
  • Automotive
  • Urban
• Agents for which hemodialysis has been shown effective as treatment modality for poisoning


  • Meprobamate
  • Metformin
  • Paraldehyde
  • Phenobarbital
  • Alcohols
  • Antibiotics
  • Boric Acid
  • Bromide
  • Calcium
  • Potassium
  • Chloral hydrates
  • Salicylates
  • Fluorides
  • Strychnine
  • lodides
  • Theophylline
  • Isoniazid
  • Thiocyanates
  • Lithium
  • Valproic Acid
• Psychiatric assessment


  • Can detect later-phase poisoning complications
  • Allow for prompt medical intervention
• A careful diagnostic approach to a poisoned patient is essential, as important medical history is often absent or unreliable
• Skillful use of antidotes is an important component of the practice of medical toxicology
• Agents for which activated charcoal has been shown as an effective means of enhanced body clearance

  • Carbamazepine
  • Dapsone
  • Digoxin (cardiac alakaloids)
  • Digitoxin (cardiac alakaloids)
  • Nadolol
  • Phenobarbital
  • Salicylates
  • Theophylline
• Use of Antidotes in Poisoning

  • Work by physically binding the toxin
  • Chemical antagonism - Preventing the toxin from exerting a deleterious effect in vivo
  • Pharmacokinetic antagonism - Facilitating body clearance of the toxin
  • Pharmacologically antagonize the effects of the toxin
  • By chemically reacting with biological systems to increase detoxifying capacity for the toxin
• True for paracetamol poisoning = given N-acetylcysteine to increase glutathione stores
• Supportive Care of the Poisoned Patient

  • Close clinical monitoring
  • Toxicokinetics - The disposition of poisons in the body from absorption, distribution, to elimination
  • Toxicodynamics - The injurious effects of toxins to the body
• Drugs with large apparent volumes of distribution, such as antidepressants and antimalarials, are not amenable to dialysis procedures for drug removal
• Overdoses of phenytoin or salicylates, the capacity of the liver to metabolize the drugs is usually exceeded, and elimination changes from first-order (constant halflife) to zero-order (variable half-life) kinetics
• Hypertension and tachycardia


  Typically seen in overdoses with amphetamines, antimuscarinic drugs, cocaine