12 USMLE Pharmacology Quick Review Questions with Answers (Set 13)

These 12 quick USMLE review questions test high-yield facts that show up again and again on the exam: TB drug monitoring, antipsychotics, dobutamine, ACE inhibitor angioedema, reflex bradycardia, half-life, spironolactone, protein binding, hormone therapy, hydroxyurea and ECT. Each question includes the correct answer.

Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.

Prefer video? Watch daily USMLE case questions on MedFocus by Dr. Ray on YouTube.

How to use this page: read the question, pick your answer, then tap Show Answer and Explanation.

Questions

Question 1. Which one of the following tests is recommended in follow-up for a patient receiving anti-tuberculous treatment (isoniazid and rifampin)?

A- Amylase and lipase tests
B- Blood glucose test
C- Liver function tests
D- Renal function tests

C- Liver function tests- Isoniazid and rifampin can both cause hepatotoxicity, so monitoring liver function tests is essential during treatment.
The correct answer is C

 

Question 2. Which one of the following medications has a significant alpha-adrenergic blocking activity?

A- Chlorpromazine
B- Clozapine
C- Haloperidol
D- Risperidone

A- Chlorpromazine- Chlorpromazine, a first-generation antipsychotic, has strong alpha-adrenergic blocking effects, which can cause hypotension. Clozapine and risperidone have weaker alpha-blocking effects, and haloperidol has minimal alpha-blocking activity.
The correct answer is A

 

Question 3. Which of the following medications is considered a selective beta-1 adrenergic agonist?

A- Amrinone
B- Dobutamine
C- Dopamine
D- Prazosin

B- Dobutamine- Dobutamine is a selective β₁-adrenergic agonist, increasing heart rate and contractility with minimal β₂ or α activity.
The correct answer is B

 

Question 4. Which of the following medications may cause acquired angioedema within days to weeks after starting it?

A- Aspirin
B- Benazepril
C- Clopidogrel
D- Propranolol

B- Benazepril- ACE inhibitors (such as benazepril) can cause acquired angioedema due to increased bradykinin levels. This reaction may occur within days, weeks, or even months after starting the medication. Aspirin, clopidogrel, and propranolol may cause other adverse effects, but they do not typically cause bradykinin-mediated angioedema.
The correct answer is B

 

Question 5. Reflex bradycardia caused by alpha-1-agonists is blocked by which of the following medications?

A- Adrenaline
B- Atropine
C- Metoprolol
D- Phenylephrine

B- Atropine- Reflex bradycardia is caused by activation of muscarinic receptors of the heart which are blocked by atropine.
The correct answer is B

 

Question 6. A 400 mg dose of a drug was administered and 200 mg of it was eliminated after two hours. Which of the following is the amount of drug left after six hours if the drug follows first-order elimination kinetics?

A- 0 mg
B- 25 mg
C- 50 mg
D- 75 mg

C- 50 mg- half of the dose is eliminated in the first two hours so its elimination half-life equals two hours. So, after 2 more hours it will be 100 mg and after six will be 50 mg.
The correct answer is C

 

Question 7. Which of the following side effects is most likely associated to spironolactone?

A- Hypercalcemia
B- Hyperglycemia
C- Hyperkalemia
D- Metabolic alkalosis

C- Hyperkalemia- This medication is a potassium-spare diuretic which means it retained K and also causes acidosis. It has no role in glucose or calcium levels.
The correct answer is C

 

Question 8. A certain drug has a high serum protein binding. Which of the following is increased as a result of injecting this drug?

A- Distribution of the drug
B- Drug interaction
C- Liver metabolism
D- Renal excretion

B- Drug interaction- Distribution of the drug to tissue, liver and kidney will decrease while drug interaction with other drug receptors’ protein will increase resulting in drug interaction.
The correct answer is B

 

Question 9. Administration of spironolactone and furosemide leads to which of the following?

A- Increase potassium loss
B- Reduce magnesium loss
C- Reduce potassium loss
D- Reduce sodium loss

C- Reduce potassium loss- Spironolactone is a K-sparing diuretic which will reduce K loss effect of thiazide diuretics.
The correct answer is C

 

Question 10. Which of the following benefits is achieved as a result of adding progesterone to estrogen in HRT?

A- Decrease bone resorption
B- Decrease the effect of estrogen on the breast
C- Decrease the occurrence of endometrial cancer
D- Increase the effect of estrogen on the heart

C- Decrease the occurrence of endometrial cancer
The correct answer is C

 

Question 11. Which of the following is the main role of hydroxyurea in the treatment of sickle cell anemia?

A- Decrease levels of HbF in red blood cells
B- Decrease oxygen affinity to HbS
C- Increase levels of HbF in red blood cells
D- Increase ability of HbS to bind 2.3-bisphosphoglycerate

C- Increase levels of HbF in red blood cells-This mechanism is not fully understood but hydroxyurea, by this action, leads to decreasing levels of HbS in RBCs.
The correct answer is C

 

Question 12. Which of the following is the most serious contraindication of electroconvulsive therapy?

A- History of fracture
B- History of seizures
C- Meningioma
D- Old age

C- Meningioma- Space occupying lesions are the most serious contraindication of electroconvulsive therapy
The correct answer is C

 

High-yield points from this set

  • Isoniazid and rifampin require liver function monitoring.
  • ACE inhibitors can cause angioedema.
  • Spironolactone causes hyperkalemia (and gynecomastia).
  • Hydroxyurea increases fetal hemoglobin in sickle cell disease.

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