MCQ on Poisoning and Antidotes

🟢 Easy (1–20)

1. What is the first step in managing a poisoning case?
   a) Start antidote immediately
   b) Identify the poison
   c) Ensure airway, breathing, circulation (ABC) ✅
   d) Perform gastric lavage
   Explanation: Stabilizing vital functions is always the first priority.
2. Which is the antidote for paracetamol poisoning?
   a) Atropine
   b) N-acetylcysteine ✅
   c) Naloxone
   d) Pralidoxime
   Explanation: N-acetylcysteine restores glutathione, protecting the liver.
3. Naloxone is an antidote for:
   a) Benzodiazepines
   b) Organophosphates
   c) Opioids ✅
   d) Iron
   Explanation: Naloxone reverses opioid-induced respiratory depression.
4. Activated charcoal is used to:
   a) Induce vomiting
   b) Enhance drug absorption
   c) Adsorb poisons in the GI tract ✅
   d) Reduce fever
   Explanation: It binds to toxins and prevents systemic absorption.
5. Which poison has a characteristic garlic odor?
   a) Cyanide
   b) Arsenic ✅
   c) Methanol
   d) Iron
   Explanation: Arsenic poisoning is associated with a garlic-like smell.
6. Which of the following is a corrosive poison?
   a) Sulphuric acid ✅
   b) Atropine
   c) Morphine
   d) Paracetamol
   Explanation: Acids like sulphuric acid cause chemical burns.
7. Which is used in benzodiazepine overdose?
   a) Atropine
   b) Flumazenil ✅
   c) Naloxone
   d) Vitamin K
   Explanation: Flumazenil is a specific benzodiazepine receptor antagonist.
8. A common household poison is:
   a) Penicillin
   b) Bleach ✅
   c) Vitamin C
   d) Zinc
   Explanation: Bleach contains sodium hypochlorite, which is toxic.
9. What is the antidote for heparin overdose?
   a) Vitamin K
   b) Protamine sulfate ✅
   c) Warfarin
   d) Desferoxamine
   Explanation: Protamine neutralizes heparin’s anticoagulant effects.
10. The antidote for iron poisoning is:
    a) Dimercaprol
    b) Flumazenil
    c) Deferoxamine ✅
    d) Naloxone
    Explanation: Deferoxamine binds iron, promoting excretion.
11. Which poison is treated with atropine and pralidoxime?
    a) Lead
    b) Opioid
    c) Organophosphates ✅
    d) Cyanide
    Explanation: These drugs counteract acetylcholine excess.
12. The universal antidote includes:
    a) Baking soda, milk, sugar
    b) Activated charcoal, tannic acid, magnesium oxide ✅
    c) Vinegar, water
    d) Lemon juice, alcohol
    Explanation: These ingredients neutralize a wide range of toxins.
13. Poisoning is most commonly managed in which hospital department?
    a) ENT
    b) Pediatrics
    c) Emergency/ICU ✅
    d) Orthopedics
    Explanation: Emergency units handle acute poisoning cases.
14. Which of the following is not a method to enhance elimination of poison?
    a) Hemodialysis
    b) Activated charcoal
    c) Forced diuresis
    d) Inducing sleep ✅
    Explanation: Inducing sleep doesn’t help in eliminating poison.
15. Which of the following can cause methanol poisoning?
    a) Soft drinks
    b) Adulterated alcohol ✅
    c) Honey
    d) Fruit juice
    Explanation: Illicit alcohol may be contaminated with methanol.
16. Which vitamin acts as an antidote to warfarin overdose?
    a) Vitamin B1
    b) Vitamin C
    c) Vitamin K ✅
    d) Vitamin D
    Explanation: Vitamin K reverses warfarin-induced bleeding.
17. A person with carbon monoxide poisoning is best treated with:
    a) Naloxone
    b) 100% oxygen ✅
    c) Atropine
    d) Activated charcoal
    Explanation: Oxygen displaces CO from hemoglobin.
18. Which of these is NOT an antidote?
    a) Atropine
    b) N-acetylcysteine
    c) Glucose
    d) Ibuprofen ✅
    Explanation: Ibuprofen is not used to treat poisonings.
19. Cherry red skin is a sign of:
    a) Cyanide poisoning
    b) Organophosphate poisoning
    c) Carbon monoxide poisoning ✅
    d) Paracetamol overdose
    Explanation: High CO levels cause oxygen displacement.
20. What does gastric lavage mean?
    a) Inducing urination
    b) Pumping the stomach ✅
    c) Giving antidotes
    d) Starting CPR
    Explanation: It’s a procedure to remove ingested poison.

🟡 Moderate (21–40)

21. The antidote for cyanide poisoning is:
    a) Flumazenil
    b) Sodium thiosulfate ✅
    c) Deferoxamine
    d) N-acetylcysteine
    Explanation: It helps detoxify cyanide into thiocyanate.
22. What is chelation therapy used for?
    a) Treating heart disease
    b) Enhancing wound healing
    c) Removing heavy metals ✅
    d) Managing fever
    Explanation: Chelators bind metals like lead and mercury.
23. Which chelating agent is used in lead poisoning?
    a) Pralidoxime
    b) Dimercaprol ✅
    c) Flumazenil
    d) Naloxone
    Explanation: Dimercaprol (BAL) binds lead for excretion.
24. Which metal poisoning presents with a blue line on gums?
    a) Zinc
    b) Iron
    c) Lead ✅
    d) Mercury
    Explanation: The Burton line is characteristic of lead poisoning.
25. Methanol toxicity can cause:
    a) Blindness ✅
    b) Paralysis
    c) Hypertension
    d) Diarrhea
    Explanation: Formic acid damages the optic nerve.
26. Which is NOT a sign of organophosphate poisoning?
    a) Salivation
    b) Miosis
    c) Tachycardia ✅
    d) Lacrimation
    Explanation: Organophosphates cause bradycardia, not tachycardia.
27. Which poison leads to rice water stools?
    a) Lead
    b) Arsenic ✅
    c) Iron
    d) Mercury
    Explanation: Arsenic causes severe watery diarrhea.
28. Mushroom poisoning is treated with:
    a) Atropine ✅
    b) Naloxone
    c) N-acetylcysteine
    d) Flumazenil
    Explanation: Muscarinic symptoms are countered with atropine.
29. Which is the main toxic metabolite in paracetamol overdose?
    a) NAPQI ✅
    b) Formic acid
    c) Methanol
    d) Acetaldehyde
    Explanation: NAPQI causes liver damage.
30. Which poisoning leads to garlic breath and Mee’s lines?
    a) Mercury
    b) Cyanide
    c) Arsenic ✅
    d) Copper
    Explanation: Arsenic accumulates in nails and causes breath odor.
31. The antidote for ethylene glycol poisoning is:
    a) Deferoxamine
    b) Fomepizole ✅
    c) N-acetylcysteine
    d) Naloxone
    Explanation: Fomepizole inhibits alcohol dehydrogenase.
32. Blue-green vomit is suggestive of:
    a) Phenol poisoning
    b) Copper sulfate ingestion ✅
    c) Zinc toxicity
    d) Paracetamol poisoning
    Explanation: Copper salts cause colored emesis.
33. What is toxidrome?
    a) Antibiotic resistance
    b) Syndrome of signs/symptoms of specific poison ✅
    c) A lab technique
    d) Drug overdose synonym
    Explanation: It helps identify classes of poisons.
34. Which route is least likely in poisoning cases?
    a) Oral
    b) Intramuscular ✅
    c) Inhalation
    d) Dermal
    Explanation: Poisoning by IM route is rare.
35. Antidote for digoxin toxicity is:
    a) Naloxone
    b) Digibind (Fab fragments) ✅
    c) Atropine
    d) Flumazenil
    Explanation: Antibodies neutralize digoxin.
36. What does the term “emesis” refer to in poisoning?
    a) Fever
    b) Vomiting ✅
    c) Bleeding
    d) Paralysis
    Explanation: Emesis is induced vomiting.
37. What is the main concern in hydrocarbon ingestion?
    a) Hypoglycemia
    b) Cardiotoxicity
    c) Aspiration pneumonitis ✅
    d) Liver failure
    Explanation: Hydrocarbons can damage lungs if aspirated.
38. Which metal causes pink disease in children?
    a) Lead
    b) Zinc
    c) Mercury ✅
    d) Arsenic
    Explanation: Chronic mercury exposure affects skin and nerves.
39. Which poison leads to bitter almond smell in breath?
    a) Cyanide ✅
    b) Methanol
    c) Iron
    d) Ethanol
    Explanation: Cyanide is famous for this diagnostic clue.
40. Which substance causes methemoglobinemia?
    a) Nitrates ✅
    b) Salicylates
    c) Paracetamol
    d) Ethylene glycol
    Explanation: Nitrates oxidize hemoglobin.

🔴 Hard (41–50)

41. Antidote for methemoglobinemia is:
    a) Fomepizole
    b) Vitamin C
    c) Methylene blue ✅
    d) Atropine
    Explanation: Methylene blue reduces methemoglobin back to hemoglobin.
42. Delayed onset of symptoms in poisoning is seen with:
    a) Cyanide
    b) Methanol ✅
    c) Atropine
    d) Iron
    Explanation: Methanol’s toxicity appears after 12–24 hours.
43. Hemodialysis is most useful in:
    a) Organophosphate poisoning
    b) Methanol poisoning ✅
    c) Cyanide poisoning
    d) Arsenic poisoning
    Explanation: Methanol and ethylene glycol are dialyzable.
44. Chronic arsenic exposure leads to:
    a) Cirrhosis
    b) Skin cancer ✅
    c) Cardiac arrest
    d) Osteoporosis
    Explanation: It is linked to skin and lung malignancies.
45. Pralidoxime is most effective when given:
    a) After 72 hours
    b) Within 1 hour ✅
    c) Only at bedtime
    d) Never
    Explanation: Early use helps reactivate cholinesterase.
46. Which poisoning may cause Parkinson-like symptoms?
    a) Manganese ✅
    b) Lead
    c) Iron
    d) Mercury
    Explanation: Manganese affects basal ganglia.
47. TCA overdose is treated with:
    a) Sodium bicarbonate ✅
    b) Naloxone
    c) Vitamin K
    d) Atropine
    Explanation: It stabilizes the cardiac membrane.
48. Which test confirms paracetamol overdose?
    a) Blood glucose
    b) Liver biopsy
    c) Plasma paracetamol level ✅
    d) Chest X-ray
    Explanation: Used with nomogram to assess risk.
49. Which plant toxin resembles atropine poisoning?
    a) Ricin
    b) Oleander
    c) Datura ✅
    d) Castor
    Explanation: Datura contains anticholinergic alkaloids.
50. An antidote that acts by enhancing metabolism is:
    a) Sodium thiosulfate
    b) Fomepizole
    c) N-acetylcysteine ✅
    d) Activated charcoal
    Explanation: NAC replenishes glutathione, detoxifying NAPQI.