ACUTE POISONING

Question 1

Acetaminophen poisoning - Mechanism of toxicity

Answer 1

Excessive production of the toxic metabolite NAPQI depletes glutathione, leading to hepatotoxicity.

Question 2

Acetaminophen poisoning - Antidote

Answer 2

N-acetylcysteine (replenishes glutathione stores).

Question 3

Salicylate (Aspirin) poisoning - Mechanism of toxicity

Answer 3

Uncouples oxidative phosphorylation and stimulates respiratory centers, leading to mixed respiratory alkalosis and metabolic acidosis.

Question 4

Salicylate (Aspirin) poisoning - Antidote

Answer 4

Activated charcoal (early), sodium bicarbonate (to alkalinize urine), hemodialysis (severe cases).

Question 5

Opioid poisoning - Mechanism of toxicity

Answer 5

Activates opioid receptors causing CNS and respiratory depression.

Question 6

Opioid poisoning - Antidote

Answer 6

Naloxone (opioid receptor antagonist).

Question 7

Benzodiazepine poisoning - Mechanism of toxicity

Answer 7

Enhances GABA activity, causing sedation and respiratory depression.

Question 8

Benzodiazepine poisoning - Antidote

Answer 8

Flumazenil (GABA receptor antagonist; use with caution due to seizure risk).

Question 9

Organophosphate poisoning - Mechanism of toxicity

Answer 9

Inhibits acetylcholinesterase, causing accumulation of acetylcholine and cholinergic symptoms.

Question 10

Organophosphate poisoning - Antidote

Answer 10

Atropine (blocks muscarinic effects) and pralidoxime (reactivates acetylcholinesterase).

Question 11

Carbon monoxide poisoning - Mechanism of toxicity

Answer 11

Binds to hemoglobin with higher affinity than oxygen, reducing oxygen delivery to tissues.

Question 12

Carbon monoxide poisoning - Antidote

Answer 12

100% oxygen or hyperbaric oxygen therapy.

Question 13

Cyanide poisoning - Mechanism of toxicity

Answer 13

Inhibits cytochrome c oxidase, blocking cellular respiration and causing hypoxia at the cellular level.

Question 14

Cyanide poisoning - Antidote

Answer 14

Hydroxocobalamin, sodium thiosulfate, or amyl nitrite (forms methemoglobin to bind cyanide).

Question 15

Methanol poisoning - Mechanism of toxicity

Answer 15

Metabolism to formic acid causes metabolic acidosis and optic nerve damage.

Question 16

Methanol poisoning - Antidote

Answer 16

Fomepizole or ethanol (inhibits alcohol dehydrogenase), bicarbonate (for acidosis), and folinic acid.

Question 17

Ethylene glycol poisoning - Mechanism of toxicity

Answer 17

Metabolism to glycolic and oxalic acid causes metabolic acidosis and renal toxicity.

Question 18

Ethylene glycol poisoning - Antidote

Answer 18

Fomepizole or ethanol (inhibits alcohol dehydrogenase), bicarbonate, and thiamine or pyridoxine.

Question 19

Beta-blocker poisoning - Mechanism of toxicity

Answer 19

Blocks beta-adrenergic receptors, causing bradycardia, hypotension, and hypoglycemia.

Question 20

Beta-blocker poisoning - Antidote

Answer 20

Glucagon (stimulates cAMP independent of beta-receptors), atropine, or inotropes like dopamine.

Question 21

Calcium channel blocker poisoning - Mechanism of toxicity

Answer 21

Inhibits calcium influx in cardiac and vascular smooth muscle, leading to bradycardia and hypotension.

Question 22

Calcium channel blocker poisoning - Antidote

Answer 22

Calcium gluconate, high-dose insulin with glucose, and vasopressors.

Question 23

Digoxin poisoning - Mechanism of toxicity

Answer 23

Inhibits Na+/K+-ATPase, increasing intracellular calcium and leading to arrhythmias.

Question 24

Digoxin poisoning - Antidote

Answer 24

Digoxin-specific antibody fragments (Digibind) and supportive care (e.g., potassium normalization).

Question 25

Tricyclic antidepressant (TCA) poisoning - Mechanism of toxicity

Answer 25

Inhibits sodium channels, causing arrhythmias, and blocks muscarinic and adrenergic receptors.

Question 26

Tricyclic antidepressant (TCA) poisoning - Antidote

Answer 26

Sodium bicarbonate (for cardiac toxicity) and supportive care.

Question 27

Iron poisoning - Mechanism of toxicity

Answer 27

Generates free radicals causing oxidative damage and metabolic acidosis.

Question 28

Iron poisoning - Antidote

Answer 28

Deferoxamine (chelates iron).

Question 29

Heparin overdose - Mechanism of toxicity

Answer 29

Excessive anticoagulation leading to bleeding.

Question 30

Heparin overdose - Antidote

Answer 30

Protamine sulfate (binds and neutralizes heparin).

Question 31

Warfarin overdose - Mechanism of toxicity

Answer 31

Inhibits vitamin K-dependent clotting factors causing excessive bleeding.

Question 32

Warfarin overdose - Antidote

Answer 32

Vitamin K, fresh frozen plasma, or prothrombin complex concentrates.

Question 33

Theophylline poisoning - Mechanism of toxicity

Answer 33

Causes excessive stimulation of the CNS and cardiovascular system via phosphodiesterase inhibition.

Question 34

Theophylline poisoning - Antidote

Answer 34

Activated charcoal (early), beta-blockers for arrhythmias, and benzodiazepines for seizures.

Question 35

Hydrofluoric acid poisoning - Mechanism of toxicity

Answer 35

Causes tissue damage and binds calcium, leading to hypocalcemia and systemic toxicity.

Question 36

Hydrofluoric acid poisoning - Antidote

Answer 36

Calcium gluconate (topical or intravenous).