CEN Toxicology and Environmental Emergencies 1 — Questions and Answers
Question 1: A patient presents with bradycardia, miosis, excessive salivation, urination, and muscle fasciculations after working in an agricultural field. Which toxidrome is this?
- Sympathomimetic toxidrome
- Anticholinergic toxidrome
- Cholinergic toxidrome (organophosphate poisoning) (Correct answer)
- Opioid toxidrome
Correct answer: Cholinergic toxidrome (organophosphate poisoning)
The SLUDGE mnemonic (Salivation, Lacrimation, Urination, Defecation, GI distress, Emesis) describes cholinergic toxidrome from organophosphate exposure.
Question 2: What is the antidote for organophosphate/cholinergic poisoning?
- N-acetylcysteine
- Atropine and pralidoxime (2-PAM) (Correct answer)
- Physostigmine
- Flumazenil
Correct answer: Atropine and pralidoxime (2-PAM)
Atropine blocks muscarinic receptors (treats secretions and bradycardia) and pralidoxime reactivates acetylcholinesterase in organophosphate poisoning.
Question 3: A patient presents after acetaminophen overdose 4 hours ago. The Rumack-Matthew nomogram is used to determine treatment. Which antidote is indicated?
- Flumazenil IV
- N-acetylcysteine (NAC) (Correct answer)
- Sodium bicarbonate infusion
- Activated charcoal only
Correct answer: N-acetylcysteine (NAC)
N-acetylcysteine replenishes glutathione, preventing toxic accumulation of NAPQI and hepatotoxicity in acetaminophen overdose.
Question 4: A patient presents with hypertension, tachycardia, hyperthermia, mydriasis, and agitation. Which toxidrome is this presentation consistent with?
- Cholinergic toxidrome
- Opioid toxidrome
- Sympathomimetic toxidrome (Correct answer)
- Sedative-hypnotic withdrawal
Correct answer: Sympathomimetic toxidrome
Hypertension, tachycardia, hyperthermia, dilated pupils, and agitation constitute the sympathomimetic toxidrome seen with cocaine or amphetamine use.
Question 5: A patient with a tricyclic antidepressant (TCA) overdose presents with a wide QRS complex and hypotension. Which treatment is most appropriate?
- Magnesium sulfate IV
- Sodium bicarbonate 1–2 mEq/kg IV bolus (Correct answer)
- Physostigmine IV
- Activated charcoal via NG tube
Correct answer: Sodium bicarbonate 1–2 mEq/kg IV bolus
Sodium bicarbonate alkalinizes the blood and increases sodium channel availability, reversing TCA-induced cardiac toxicity and wide QRS.
Question 6: Which antidote is used for methanol or ethylene glycol poisoning to competitively inhibit alcohol dehydrogenase?
- Ethanol
- Fomepizole (4-MP) (Correct answer)
- N-acetylcysteine
- Hydroxocobalamin
Correct answer: Fomepizole (4-MP)
Fomepizole is the preferred antidote for methanol and ethylene glycol poisoning as it inhibits alcohol dehydrogenase without the side effects of ethanol.
CEN Toxicology and Environmental Emergencies 1
A patient presents with bradycardia, miosis, excessive salivation, urination, and muscle fasciculations after working in an agricultural field.
Which toxidrome is this?