ACUTE POISONING Flashcards
Acetaminophen poisoning - Mechanism of toxicity
Excessive production of the toxic metabolite NAPQI depletes glutathione, leading to hepatotoxicity.
Acetaminophen poisoning - Antidote
N-acetylcysteine (replenishes glutathione stores).
Salicylate (Aspirin) poisoning - Mechanism of toxicity
Uncouples oxidative phosphorylation and stimulates respiratory centers, leading to mixed respiratory alkalosis and metabolic acidosis.
Salicylate (Aspirin) poisoning - Antidote
Activated charcoal (early), sodium bicarbonate (to alkalinize urine), hemodialysis (severe cases).
Opioid poisoning - Mechanism of toxicity
Activates opioid receptors causing CNS and respiratory depression.
Opioid poisoning - Antidote
Naloxone (opioid receptor antagonist).
Benzodiazepine poisoning - Mechanism of toxicity
Enhances GABA activity, causing sedation and respiratory depression.
Benzodiazepine poisoning - Antidote
Flumazenil (GABA receptor antagonist; use with caution due to seizure risk).
Organophosphate poisoning - Mechanism of toxicity
Inhibits acetylcholinesterase, causing accumulation of acetylcholine and cholinergic symptoms.
Organophosphate poisoning - Antidote
Atropine (blocks muscarinic effects) and pralidoxime (reactivates acetylcholinesterase).
Carbon monoxide poisoning - Mechanism of toxicity
Binds to hemoglobin with higher affinity than oxygen, reducing oxygen delivery to tissues.
Carbon monoxide poisoning - Antidote
100% oxygen or hyperbaric oxygen therapy.
Cyanide poisoning - Mechanism of toxicity
Inhibits cytochrome c oxidase, blocking cellular respiration and causing hypoxia at the cellular level.
Cyanide poisoning - Antidote
Hydroxocobalamin, sodium thiosulfate, or amyl nitrite (forms methemoglobin to bind cyanide).
Methanol poisoning - Mechanism of toxicity
Metabolism to formic acid causes metabolic acidosis and optic nerve damage.
Methanol poisoning - Antidote
Fomepizole or ethanol (inhibits alcohol dehydrogenase), bicarbonate (for acidosis), and folinic acid.
Ethylene glycol poisoning - Mechanism of toxicity
Metabolism to glycolic and oxalic acid causes metabolic acidosis and renal toxicity.
Ethylene glycol poisoning - Antidote
Fomepizole or ethanol (inhibits alcohol dehydrogenase), bicarbonate, and thiamine or pyridoxine.
Beta-blocker poisoning - Mechanism of toxicity
Blocks beta-adrenergic receptors, causing bradycardia, hypotension, and hypoglycemia.
Beta-blocker poisoning - Antidote
Glucagon (stimulates cAMP independent of beta-receptors), atropine, or inotropes like dopamine.
Calcium channel blocker poisoning - Mechanism of toxicity
Inhibits calcium influx in cardiac and vascular smooth muscle, leading to bradycardia and hypotension.
Calcium channel blocker poisoning - Antidote
Calcium gluconate, high-dose insulin with glucose, and vasopressors.
Digoxin poisoning - Mechanism of toxicity
Inhibits Na+/K+-ATPase, increasing intracellular calcium and leading to arrhythmias.
Digoxin poisoning - Antidote
Digoxin-specific antibody fragments (Digibind) and supportive care (e.g., potassium normalization).
Tricyclic antidepressant (TCA) poisoning - Mechanism of toxicity
Inhibits sodium channels, causing arrhythmias, and blocks muscarinic and adrenergic receptors.
Tricyclic antidepressant (TCA) poisoning - Antidote
Sodium bicarbonate (for cardiac toxicity) and supportive care.
Iron poisoning - Mechanism of toxicity
Generates free radicals causing oxidative damage and metabolic acidosis.
Iron poisoning - Antidote
Deferoxamine (chelates iron).
Heparin overdose - Mechanism of toxicity
Excessive anticoagulation leading to bleeding.
Heparin overdose - Antidote
Protamine sulfate (binds and neutralizes heparin).
Warfarin overdose - Mechanism of toxicity
Inhibits vitamin K-dependent clotting factors causing excessive bleeding.
Warfarin overdose - Antidote
Vitamin K, fresh frozen plasma, or prothrombin complex concentrates.
Theophylline poisoning - Mechanism of toxicity
Causes excessive stimulation of the CNS and cardiovascular system via phosphodiesterase inhibition.
Theophylline poisoning - Antidote
Activated charcoal (early), beta-blockers for arrhythmias, and benzodiazepines for seizures.
Hydrofluoric acid poisoning - Mechanism of toxicity
Causes tissue damage and binds calcium, leading to hypocalcemia and systemic toxicity.
Hydrofluoric acid poisoning - Antidote
Calcium gluconate (topical or intravenous).