Free Questions and Answers for All Medical Students all over the World
10 USMLE Pharmacology Quick Review Questions with Answers (Set 9)
These 10 quick USMLE review questions test high-yield facts that show up again and again on the exam: succimer, sumatriptan, naloxone, antiplatelet combinations, ezetimibe, glaucoma, statins, tachyphylaxis, nicotinic receptors and scopolamine. Each question includes the correct answer.
Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.
How to use this page: read the question, pick your answer, then tap Show Answer and Explanation.
Questions
Question 1. Which of the following substances is used in mercury poisoning?
A- Flumazenil
B- Fomepizole
C- Methylene blue
D- Succimer
D- Succimer- Succimer (DMSA) is a chelating agent used in cases of heavy metal poisoning, including mercury. Flumazenil reverses benzodiazepines, fomepizole treats methanol and ethylene glycol toxicity, and methylene blue treats methemoglobinemia.
The correct answer is D
Question 2. Which of the following conditions could be a serious side effect of sumatriptan?
A- Coronary vasospasm- Sumatriptan is a serotonin (5-HT1B/1D) agonist that can cause coronary vasospasm, which may lead to chest pain or myocardial ischemia. The other conditions are not characteristic complications of sumatriptan.
The correct answer is A
Question 3. Naloxone is the treatment of choice of which one of the following toxicities?
C- Hydrocodone toxicity- Naloxone is an opioid antagonist used to reverse opioid toxicity, including hydrocodone overdose. It is not effective for tricyclic antidepressants (amitriptyline), SSRIs (citalopram), or stimulants (methylphenidate).
The correct answer is C
Question 4. Administration of clopidogrel with aspirin is an example of which of the following drug interactions?
A- Additive- Aspirin and clopidogrel each inhibit platelet aggregation through different mechanisms. When given together, their antiplatelet effects add up, producing a stronger combined effect that equals the sum of their individual actions. This is additive, not synergistic (which would be greater than the sum).
The correct answer is A
Question 5. Which of the following medications prevents cholesterol absorption at small intestine brush border?
B- Ezetimibe- Ezetimibe blocks the NPC1L1 transporter at the small-intestine brush border, preventing dietary and biliary cholesterol absorption. The other drugs lower lipid levels by different mechanisms.
The correct answer is B
Question 6. Which one of these medication groups is contraindicated in a patient with narrow-angle glaucoma?
D- Muscarinic-receptor antagonists- Muscarinic-receptor antagonists cause pupillary dilation, which can further narrow the anterior chamber angle and precipitate acute angle-closure glaucoma. They are therefore contraindicated in narrow-angle glaucoma.
The correct answer is D
Question 7. Which of the following is the main site of action of HMG-CoA reductase inhibitors?
A- Blood
B- Liver
C- Kidney
D- GI tract
B- Liver- HMG-CoA reductase inhibitors (statins) act primarily in the liver, where they reduce cholesterol synthesis and upregulate LDL receptors to lower blood LDL levels.
The correct answer is B
Question 8. Acute decrease in response to a drug after initial or repeated intake is known as which of the following drug interactions?
D- Tachyphylactic- Tachyphylaxis refers to an acute and rapid decrease in the response to a drug after initial or repeated doses. It is not additive, permissive, or synergistic.
The correct answer is D
Question 9. Which one of the following correctly describes nicotinic ACh receptors?
C- Ligand-gated Na+/K+ channels- Nicotinic acetylcholine receptors are ligand-gated ion channels that open when acetylcholine binds, allowing Na⁺ to flow in and K⁺ to flow out, generating depolarization. They are not GPCRs or enzyme-linked receptors.
The correct answer is C
Question 10. Which of the following medications is the drug of choice for motion sickness?
C- Scopolamine- Scopolamine is the preferred medication for motion sickness because it effectively blocks muscarinic receptors in the vestibular system. The other drugs are anticholinergics but are used for different conditions.
The correct answer is C
High-yield points from this set
Succimer chelates lead and mercury.
Triptans can cause coronary vasospasm.
Anticholinergics are contraindicated in narrow-angle glaucoma.
Scopolamine is the drug of choice for motion sickness.