Q.1 Which of the following is the most common cause of acute acetaminophen (paracetamol) poisoning?
Intentional overdose
Accidental ingestion in children
Chronic therapeutic use
Topical application
Explanation - Acetaminophen poisoning is most commonly due to intentional overdose, often in a suicide attempt, although accidental ingestion in children is also possible.
Correct answer is: Intentional overdose
Q.2 Which antidote is used for acetaminophen toxicity?
N-acetylcysteine
Atropine
Deferoxamine
Naloxone
Explanation - N-acetylcysteine replenishes glutathione stores and is the specific antidote for acetaminophen toxicity, preventing hepatic injury.
Correct answer is: N-acetylcysteine
Q.3 A patient presents with salivation, lacrimation, urination, diarrhea, and muscle fasciculations after pesticide exposure. What is the most likely toxin?
Organophosphate
Carbon monoxide
Methanol
Cyanide
Explanation - Organophosphate poisoning inhibits acetylcholinesterase, leading to cholinergic symptoms including SLUDGE (salivation, lacrimation, urination, diarrhea, gastrointestinal upset, emesis).
Correct answer is: Organophosphate
Q.4 Which antidote is used in organophosphate poisoning?
Atropine
N-acetylcysteine
Vitamin K
Flumazenil
Explanation - Atropine is a muscarinic antagonist that counters the effects of excess acetylcholine in organophosphate poisoning. Pralidoxime may also be used to reactivate acetylcholinesterase.
Correct answer is: Atropine
Q.5 A 30-year-old patient is found unconscious with pinpoint pupils and respiratory depression. Which toxin is most likely responsible?
Opioid
Benzodiazepine
Cyanide
Carbon monoxide
Explanation - Opioid overdose classically presents with the triad of CNS depression, respiratory depression, and miosis (pinpoint pupils).
Correct answer is: Opioid
Q.6 Which antidote is used in opioid overdose?
Naloxone
Flumazenil
Deferoxamine
Atropine
Explanation - Naloxone is an opioid antagonist that reverses the effects of opioid overdose by competitively binding to opioid receptors.
Correct answer is: Naloxone
Q.7 Which of the following is a classic sign of cyanide poisoning?
Cherry-red skin
Pale, clammy skin
Yellow sclera
Greenish urine
Explanation - Cyanide poisoning prevents cellular oxygen utilization, leading to increased oxygen in arterial blood and characteristic cherry-red skin.
Correct answer is: Cherry-red skin
Q.8 What is the antidote combination for cyanide poisoning?
Amyl nitrite, sodium nitrite, sodium thiosulfate
Atropine and pralidoxime
N-acetylcysteine
Naloxone
Explanation - Nitrites induce methemoglobinemia, which binds cyanide, while sodium thiosulfate acts as a sulfur donor to convert cyanide to the less toxic thiocyanate.
Correct answer is: Amyl nitrite, sodium nitrite, sodium thiosulfate
Q.9 A patient presents with confusion, ataxia, and horizontal nystagmus after drinking moonshine. Which toxin is suspected?
Methanol
Ethylene glycol
Ethanol
Isopropanol
Explanation - Methanol is metabolized to formic acid, causing metabolic acidosis, CNS depression, visual disturbances, and ataxia.
Correct answer is: Methanol
Q.10 Which antidote is used in methanol poisoning?
Fomepizole or ethanol
N-acetylcysteine
Naloxone
Atropine
Explanation - Fomepizole or ethanol competitively inhibits alcohol dehydrogenase, preventing methanol metabolism to toxic formic acid.
Correct answer is: Fomepizole or ethanol
Q.11 Which toxic substance commonly causes renal failure after ingestion of antifreeze?
Ethylene glycol
Methanol
Arsenic
Lead
Explanation - Ethylene glycol is metabolized to oxalate, which precipitates in renal tubules and causes acute kidney injury.
Correct answer is: Ethylene glycol
Q.12 Which laboratory finding is most characteristic of ethylene glycol poisoning?
Calcium oxalate crystals in urine
High bilirubin
Methemoglobinemia
Hyperkalemia
Explanation - Calcium oxalate crystals in urine indicate metabolism of ethylene glycol to oxalate, which precipitates in renal tubules.
Correct answer is: Calcium oxalate crystals in urine
Q.13 Which antidote is used in ethylene glycol poisoning?
Fomepizole or ethanol
Deferoxamine
Atropine
Naloxone
Explanation - Fomepizole or ethanol inhibits alcohol dehydrogenase, preventing the formation of toxic metabolites of ethylene glycol.
Correct answer is: Fomepizole or ethanol
Q.14 Which heavy metal poisoning presents with garlic breath, hypotension, and multi-organ failure?
Arsenic
Lead
Mercury
Iron
Explanation - Acute arsenic poisoning causes GI symptoms, hypotension, multi-organ failure, and garlic odor on the breath.
Correct answer is: Arsenic
Q.15 Which chelating agent is used for arsenic poisoning?
Dimercaprol (British anti-Lewisite, BAL)
Deferoxamine
EDTA
Penicillamine
Explanation - Dimercaprol binds arsenic to form a stable complex that can be excreted in urine, making it the antidote of choice.
Correct answer is: Dimercaprol (British anti-Lewisite, BAL)
Q.16 A child presents with vomiting, abdominal pain, and blue line on gums. Which poisoning is suspected?
Lead
Mercury
Arsenic
Iron
Explanation - Chronic lead poisoning can present with abdominal pain, vomiting, constipation, and a characteristic blue line on the gums.
Correct answer is: Lead
Q.17 Which chelating agent is preferred in lead poisoning in children?
Succimer (DMSA)
Dimercaprol
Deferoxamine
Penicillamine
Explanation - Succimer is an oral chelating agent preferred for mild to moderate lead poisoning in children.
Correct answer is: Succimer (DMSA)
Q.18 Which of the following is a common feature of organophosphate poisoning?
Muscarinic and nicotinic symptoms
Hypertension and tachycardia
Hypoglycemia
Methemoglobinemia
Explanation - Organophosphate poisoning inhibits acetylcholinesterase, causing excessive acetylcholine at muscarinic (SLUDGE) and nicotinic (muscle fasciculations, weakness) sites.
Correct answer is: Muscarinic and nicotinic symptoms
Q.19 Which poison commonly causes methemoglobinemia?
Nitrites
Organophosphates
Acetaminophen
Cyanide
Explanation - Nitrites oxidize hemoglobin to methemoglobin, which cannot carry oxygen, leading to hypoxia and cyanosis.
Correct answer is: Nitrites
Q.20 Which antidote is used in methemoglobinemia?
Methylene blue
N-acetylcysteine
Naloxone
Flumazenil
Explanation - Methylene blue acts as an electron donor to reduce methemoglobin back to functional hemoglobin.
Correct answer is: Methylene blue
Q.21 Which of the following is a common source of acute iron poisoning in children?
Iron supplements
Lead paint
Mercury thermometers
Pesticides
Explanation - Accidental ingestion of iron tablets is a common cause of acute iron poisoning in children, leading to GI bleeding and metabolic acidosis.
Correct answer is: Iron supplements
Q.22 Which antidote is used in severe iron poisoning?
Deferoxamine
Dimercaprol
Naloxone
Fomepizole
Explanation - Deferoxamine is an iron-chelating agent used in severe iron poisoning to bind free iron and promote renal excretion.
Correct answer is: Deferoxamine
Q.23 A patient presents with CNS depression, hypotension, and fruity odor on the breath after ingestion. Which toxin is likely?
Isopropanol
Methanol
Ethylene glycol
Acetaminophen
Explanation - Isopropanol poisoning causes CNS depression, hypotension, and a characteristic fruity odor (acetone) on the breath.
Correct answer is: Isopropanol
Q.24 Which of the following is the most appropriate management for isopropanol poisoning?
Supportive care and IV fluids
Fomepizole
N-acetylcysteine
Naloxone
Explanation - Isopropanol is metabolized to acetone, which is less toxic. Management is primarily supportive with IV fluids and monitoring.
Correct answer is: Supportive care and IV fluids