Over-the-counter and Prescription Drug Overdoses Practice Questions

25 multiple-choice questions on Over-the-counter and prescription drug overdoses for paramedic and EMT students, from Chapter 28 (Toxicology). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. For 3 days a mother has given her feverish 2-year-old an adult-strength acetaminophen dose every 3 hours. The child is now sleepy and vomiting. This child is at risk for:

   1. A. No harm, since each dose was small
   2. B. Kidney stones from the dye in the pills
   3. C. Liver injury from repeated overdosing
   4. D. Aspirin-like bleeding of the stomach
   Show answer

   Answer: C. Liver injury from repeated overdosing

   Repeated doses above the recommended amount can add up to a toxic total over days, especially in small children and in illness with poor intake, and can cause liver failure even though no single dose was large. These children need transport and acetaminophen levels with liver tests. Acetaminophen does not cause kidney stones or the gastric bleeding typical of aspirin and NSAIDs.

2. Acetaminophen damages the liver because:

   1. A. A toxic metabolite builds up when glutathione is depleted
   2. B. The parent drug directly blocks liver blood flow
   3. C. It causes antibodies to attack liver cells
   4. D. It blocks the liver's ability to make clotting factors only
   Show answer

   Answer: A. A toxic metabolite builds up when glutathione is depleted

   In overdose, the normal pathways saturate and the metabolite NAPQI accumulates once glutathione runs out. N-acetylcysteine replenishes glutathione.

3. N-acetylcysteine is most effective when started within:

   1. A. 30 minutes of acetaminophen ingestion
   2. B. 72 hours of acetaminophen ingestion
   3. C. 7 days of acetaminophen ingestion
   4. D. 8 hours of acetaminophen ingestion
   Show answer

   Answer: D. 8 hours of acetaminophen ingestion

   NAC prevents nearly all liver injury when given within 8 hours. It still helps later, but effectiveness declines, so early transport matters.

4. Acetaminophen overdose is particularly hidden because it is found in:

   1. A. Many combination cold, flu, and opioid products
   2. B. Only prescription-strength pain medicines from a pharmacy
   3. C. Very few products in the average home
   4. D. Only products labeled for children
   Show answer

   Answer: A. Many combination cold, flu, and opioid products

   Patients may unknowingly take several products containing acetaminophen and exceed safe doses. Ask specifically about combination products such as hydrocodone-acetaminophen.

5. An 82-year-old who takes aspirin daily for arthritis is confused, febrile, and breathing fast. Chronic salicylate toxicity in older adults is often missed because it:

   1. A. Never changes the vital signs
   2. B. Occurs only after a suicide attempt
   3. C. Mimics sepsis or delirium
   4. D. Always causes ringing in the ears
   Show answer

   Answer: C. Mimics sepsis or delirium

   Chronic salicylate toxicity builds up over days and causes confusion, fever, tachypnea, and acidosis, so it is easily mistaken for sepsis, dementia, or delirium, and it carries a higher death rate than acute overdose. Ask about all aspirin and salicylate products. It does change vital signs (fast breathing, fever), it is often unintentional, and tinnitus is common but may be absent or unreported in older adults.

6. The acid-base pattern in salicylate toxicity in adults is usually:

   1. A. Respiratory acidosis with a metabolic alkalosis
   2. B. Respiratory alkalosis with a metabolic acidosis
   3. C. Pure metabolic alkalosis from vomiting
   4. D. Pure respiratory acidosis from sedation
   Show answer

   Answer: B. Respiratory alkalosis with a metabolic acidosis

   Salicylates stimulate breathing early, then cause an anion gap metabolic acidosis. Patients compensate by breathing fast, which is why sedation is so dangerous.

7. A 40-year-old who took a large amount of quetiapine is sleepy with HR 124 and BP 78/40. Low blood pressure in this overdose is caused mainly by:

   1. A. Direct weakening of the heart muscle itself
   2. B. Hidden bleeding from a stomach ulcer
   3. C. Loss of fluid from heavy urination
   4. D. Alpha-1 blockade dilating blood vessels
   Show answer

   Answer: D. Alpha-1 blockade dilating blood vessels

   Quetiapine and similar antipsychotics block alpha-1 receptors, dilating blood vessels and causing hypotension with a reflex tachycardia, along with sedation and anticholinergic effects. Treat with IV fluids first, then a direct vasopressor such as norepinephrine if needed. Direct pump failure is not the main effect. The drug does not cause GI bleeding or a large diuresis.

8. A woman took 60 citalopram tablets. Unlike most SSRI overdoses, a large citalopram overdose is concerning because it can cause:

   1. A. Pinpoint pupils with slow breathing
   2. B. Severe low blood glucose
   3. C. QT prolongation and seizures
   4. D. Bloody vomiting from ulcers
   Show answer

   Answer: C. QT prolongation and seizures

   Most SSRI overdoses are mild, but citalopram and escitalopram can prolong the QT interval, cause torsades de pointes, and cause seizures, sometimes hours after ingestion, so these patients need cardiac monitoring. Pinpoint pupils and apnea suggest opioids. Citalopram does not cause hypoglycemia or GI bleeding in overdose.

9. A man with type 2 diabetes took a large overdose of his metformin. Compared with a sulfonylurea overdose, the main danger is:

   1. A. Prolonged hypoglycemia
   2. B. Severe lactic acidosis
   3. C. Bradycardia and heart block
   4. D. Delayed liver failure
   Show answer

   Answer: B. Severe lactic acidosis

   Metformin does not stimulate insulin release, so it rarely causes hypoglycemia, but a large overdose can cause severe lactic acidosis with vomiting, rapid breathing, shock, and altered mental status; treatment may include dialysis. Prolonged, recurrent hypoglycemia is the hallmark of sulfonylureas. Bradycardia and heart block suggest beta blockers, calcium channel blockers, or digoxin. Delayed liver failure fits acetaminophen.

10. The ECG finding most associated with dangerous tricyclic antidepressant toxicity is:

    1. A. A narrow QRS with peaked P waves in lead II
    2. B. ST depression with a scooped appearance
    3. C. A shortened QT with U waves present
    4. D. A QRS over 100 ms and a tall R wave in aVR
    Show answer

    Answer: D. A QRS over 100 ms and a tall R wave in aVR

    A QRS over 100 ms predicts seizures and over 160 ms predicts dysrhythmias. Scooped ST depression is a digoxin effect.

11. A 2-year-old chewed several of a parent's benzonatate cough capsules a few minutes ago. You should be prepared for:

    1. A. Rapid seizures and cardiac arrest
    2. B. Only a mild, numb sore throat
    3. C. Liver failure about 3 days later
    4. D. Slow onset of severe constipation
    Show answer

    Answer: A. Rapid seizures and cardiac arrest

    Benzonatate is a local anesthetic, and in young children even one or two capsules can cause restlessness, seizures, dysrhythmias, and cardiac arrest within 15 minutes to an hour, so move quickly and monitor closely. The numbness is real but is not the main danger. Delayed liver failure fits acetaminophen, and constipation is not a feature.

12. TCA overdoses can deteriorate quickly. Patients typically worsen:

    1. A. Only after 24 hours of observation
    2. B. Only if the dose exceeded 100 tablets
    3. C. After a long latent phase of 2 to 3 days
    4. D. Within the first few hours
    Show answer

    Answer: D. Within the first few hours

    TCA patients can go from alert to seizing and hypotensive within an hour. Charcoal and early airway control may be needed before the crash.

13. A 70-year-old on metoprolol took extra doses and has HR 38, BP 70/40, and a glucose of 54 mg/dL. Medical control orders glucagon 5 mg slow IV. The adverse effect you should be most ready for is:

    1. A. Vomiting, so have suction ready
    2. B. Severe hypoglycemia after the dose
    3. C. Worsening bradycardia after the push
    4. D. Generalized seizures from the bolus
    Show answer

    Answer: A. Vomiting, so have suction ready

    Nausea and vomiting are the most common effects of the large glucagon doses used for beta-blocker poisoning, and a hypotensive, drowsy patient may aspirate, so position the patient and have suction ready. Glucagon raises blood glucose rather than lowering it, so hypoglycemia is not expected (the low glucose here is itself a clue to beta blockade). It raises heart rate and contractility by increasing cAMP through a non-beta-receptor pathway, so worsening bradycardia is not its effect. Seizures are not a recognized effect of glucagon. AHA 2023 rates a glucagon bolus and infusion as reasonable (COR 2a) and high-dose insulin as recommended (COR 1) for beta-blocker shock. (AHA 2023 toxicology update; StatPearls, Glucagon.)

14. After an overdose of his heart medication, a man has HR 40, BP 70/40, and a blood glucose of 310 mg/dL. He is not diabetic. The drug he most likely took is:

    1. A. A beta-adrenergic blocker
    2. B. A cardiac glycoside (digoxin)
    3. C. A calcium channel blocker
    4. D. A central alpha-2 agonist
    Show answer

    Answer: C. A calcium channel blocker

    Calcium channel blockers also block insulin release from the pancreas, so bradycardia and hypotension with high glucose point to them, and the degree of hyperglycemia tracks severity. Beta-blocker overdoses tend to cause normal or low glucose, especially in children. Digoxin toxicity causes vomiting, visual changes, and dysrhythmias without hyperglycemia. Clonidine causes sedation, small pupils, and bradycardia, not marked hyperglycemia.

15. High-dose insulin with dextrose is used in severe calcium channel blocker overdose to:

    1. A. Lower the dangerously high blood sugar level
    2. B. Improve heart muscle glucose use and contractility
    3. C. Bind the drug in the bloodstream for renal excretion
    4. D. Reverse the channel blockade at the receptor
    Show answer

    Answer: B. Improve heart muscle glucose use and contractility

    The poisoned heart is energy starved, and insulin improves its glucose uptake and pumping. Dextrose is given with it to prevent hypoglycemia.

16. A 30-year-old swallowed a bottle of his father's digoxin 2 hours ago. His potassium is 6.2 mEq/L. This potassium level means that:

    1. A. Only a small amount was absorbed
    2. B. The level is unrelated to the overdose
    3. C. Toxicity is severe; Fab is indicated
    4. D. He is protected against dysrhythmias
    Show answer

    Answer: C. Toxicity is severe; Fab is indicated

    In acute digoxin poisoning, digoxin blocks the sodium-potassium pump and potassium leaks out of cells, so hyperkalemia reflects severe poisoning and predicts death; a potassium above 5 to 5.5 mEq/L is an indication for digoxin immune Fab. It does not suggest a small ingestion, it is caused by the drug, and it increases rather than decreases dysrhythmia risk.

17. A 3-year-old drank most of a bottle of albuterol syrup. He is tremulous with HR 170. The lab abnormality the hospital will most expect is:

    1. A. High potassium
    2. B. Low sodium
    3. C. High calcium
    4. D. Low potassium
    Show answer

    Answer: D. Low potassium

    Large doses of a beta-2 agonist drive potassium into cells, causing hypokalemia, along with tachycardia, tremor, agitation, and high glucose. This is the same effect that makes albuterol useful for treating hyperkalemia, so high potassium is the opposite of what happens. Albuterol does not cause low sodium or high calcium.

18. The ECG rhythm that is highly specific for digoxin toxicity is:

    1. A. Bidirectional ventricular tachycardia
    2. B. Polymorphic torsades de pointes
    3. C. Sinus tachycardia with frequent PACs and PVCs
    4. D. Atrial flutter with rapid conduction
    Show answer

    Answer: A. Bidirectional ventricular tachycardia

    Bidirectional VT, with beats alternating axis, is nearly pathognomonic. Torsades is linked to QT-prolonging drugs such as methadone.

19. A man took 20 extended-release nifedipine tablets 1 hour ago. He is alert with HR 88 and BP 128/80 and wants to stay home. The best reasoning is that:

    1. A. Normal vitals now rule out toxicity
    2. B. Toxicity can be delayed many hours
    3. C. Nifedipine is not toxic in overdose
    4. D. Charcoal at home will be sufficient
    Show answer

    Answer: B. Toxicity can be delayed many hours

    Extended-release products release drug slowly, so severe hypotension and bradycardia can start 12 or more hours after ingestion; poison centers usually advise about 24 hours of monitoring. Normal early vitals do not rule out toxicity, and calcium channel blockers are among the most dangerous cardiac drugs in overdose. Charcoal is not given at home and does not replace monitoring.

20. A 2-year-old ate several of his mother's prenatal vitamins with iron and has vomiting and bloody diarrhea. Iron toxicity is dangerous because:

    1. A. Iron is very well bound by activated charcoal
    2. B. A quiet phase can precede shock and liver failure
    3. C. Symptoms always resolve within about 6 hours
    4. D. It causes only mild stomach upset in small children
    Show answer

    Answer: B. A quiet phase can precede shock and liver failure

    Iron poisoning has GI, latent, and shock phases, so a quiet period does not mean recovery. Charcoal does not bind iron; deferoxamine is the antidote.

21. A parent calls about a child who swallowed iron tablets. To judge how dangerous the ingestion is, the poison center most needs:

    1. A. The total weight of each tablet
    2. B. Whether the tablets were chewable
    3. C. The elemental iron per tablet
    4. D. The brand of the multivitamin
    Show answer

    Answer: C. The elemental iron per tablet

    Toxicity is estimated from the dose of elemental iron per kilogram, and iron salts differ (ferrous sulfate is about 20% elemental iron, ferrous fumarate about 33%), so the label's elemental iron content and the number of tablets are key; about 20 mg/kg causes GI symptoms and over 60 mg/kg can be serious. A tablet's total weight includes the salt and fillers, so it overstates the iron. Chewable or not and the brand name do not give the dose.

22. A 2-year-old may have swallowed one of his grandmother's methadone tablets an hour ago. He looks well. The best plan is to:

    1. A. Transport; effects may be delayed
    2. B. Leave him with the parents to watch
    3. C. Give naloxone now to prevent effects
    4. D. Induce vomiting to remove the tablet
    Show answer

    Answer: A. Transport; effects may be delayed

    Methadone has a long and variable onset and half-life, and a single tablet can cause delayed coma and apnea in a toddler, so the child needs transport and prolonged monitoring even if he looks well. Watching at home misses late respiratory depression. Naloxone is given for respiratory depression, not to prevent it, and it would wear off long before methadone. Inducing vomiting is not recommended.

23. A 3-year-old who swallowed one of his grandfather's metoprolol tablets is sleepy. Besides heart rate and BP, the most important bedside check is:

    1. A. His core body temperature
    2. B. His pupil size and reactivity
    3. C. His urine output for an hour
    4. D. His blood glucose level
    Show answer

    Answer: D. His blood glucose level

    Beta blockers impair glycogen breakdown and gluconeogenesis, and young children have small glycogen stores, so hypoglycemia is a common and treatable cause of drowsiness or seizures after a beta-blocker ingestion. Temperature, pupils, and urine output matter less here and would not change immediate care the way a low glucose would.

24. The drugs known for being dangerous to a toddler even in a single tablet include:

    1. A. Antacids, stool softeners, and multivitamins
    2. B. Acetaminophen, ibuprofen, and loratadine syrup
    3. C. Penicillin, amoxicillin, and cephalexin
    4. D. Calcium channel blockers, TCAs, sulfonylureas
    Show answer

    Answer: D. Calcium channel blockers, TCAs, sulfonylureas

    These drugs can cause death in a small child from just one or two pills. Most common OTC analgesics are toxic only in much larger amounts.

25. A patient who overdosed on ibuprofen is most likely to have:

    1. A. Severe early liver failure within 12 hours
    2. B. Profound bradycardia and complete heart block
    3. C. Nausea and abdominal pain with a mild course
    4. D. Tinnitus with marked respiratory alkalosis
    Show answer

    Answer: C. Nausea and abdominal pain with a mild course

    NSAID overdoses usually cause mild GI symptoms, though massive doses can cause acidosis and seizures. Tinnitus and alkalosis point to aspirin instead.