10 USMLE Pharmacology Quick Review Questions with Answers (Set 17)

These 10 quick USMLE review questions test high-yield facts that show up again and again on the exam: digoxin, flumazenil, infliximab, tardive dyskinesia, ursodiol, lactase, beta-1 effects, hypnotic overdose, clozapine and labetalol. 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 of the following is the role of infliximab in the management of rheumatoid arthritis?

A- Inhibition of dihydrofolate reductase
B- It is a TNF-alpha receptor agonist
C- It is a TNF-alpha receptor antagonist
D- It neutralizes the activity of TNF-alpha by binding to soluble forms of it

D- It neutralizes the activity of TNF-alpha by binding to soluble forms of it- It prevents the effective binding of TNF-alpha with its receptors so, it is not direct receptor antagonist.
The correct answer is D

 

Question 2. Which of the following is the most frequent and irreversible side effect of typical anti-psychotics?

A- Akathisia
B- Anxiety
C- Dystonia
D- Tardive dyskinesia

D- Tardive dyskinesia- It usually occurs after 2 years of using these drugs. It is devastating and irreversible.
The correct answer is D

 

Question 3. Which of the following is the mechanism of action of ursodiol to reduce the size of gallstones in the common bile duct?

A- Dissolving calcium from the stone
B- Dissolving cholesterol from the stone
C- Reducing bile synthesis
D- Relaxation of the common bile duct

B- Dissolving cholesterol form the stone- Ursodiol is a bile acid helps break down cholesterol from stones in the gallbladder. It is secreted by the liver and absorbed in the intestine.
The correct answer is B

 

Question 4. Which of these substances should be taken before the consumption of milk in a patient who complains of abdominal pain and cramping after drinking milk?

A- Acetaminophen
B- Aspirin
C- Lactase
D- Niacin

C- Lactase- This is most likely a case of lactose intolerance. Lactase may help before consumption of dairy products.
The correct answer is C

 

Question 5. Which one of the following effects is correlated to direct beta1-adrenoreceptor stimulation?

A- Bradycardia
B- Bronchodilation
C- Tachycardia
D- Vasoconstriction

C- Tachycardia- Beta 1 affects the heart causing tachycardia while Beta 2 stimulation leads to bronchodilation.
The correct answer is C

 

Question 6. Which of the following is the most likely cause of death in cases of overdose of hypnotics?

A- Cerebral edema
B- Depression of the medullary respiratory center
C- Hypothermia
D- Status epilepticus

B- Depression of the medullary respiratory center- Overdose of hypnotics can cause drowsiness, ataxia, stupor, coma and fatal central respiratory arrest.
The correct answer is B

 

Question 7. Which one of the following antipsychotics has higher affinity to both dopamine and serotonin receptors?

A- Clozapine
B- Fluphenazine
C- Haloperidol
D- Thioridazine

A- Clozapine- It is the only one listed that has affinity to both types of receptors.
The correct answer is A

 

Question 8. A 30-year-old man with hypertension is prescribed labetalol. It antagonizes which of the following receptors to be effective against hypertension?

A- Alpha-adrenoceptors
B- Beta-adrenoceptors
C- Both alpha and beta adrenoceptors
D- Nicotinic receptors

C- Both alpha and beta adrenoceptors- Labetalol blocks both of these receptors to lower the blood pressure through decreasing systemic vascular resistance.
The correct answer is C

 

Question 9. Which of the following is the most effective role of probenecid in treating gout?

A- Probenecid decreases inflammation of affected joints
B- Probenecid decreases the production of uric acid
C- Probenecid decreases the reabsorption of uric acid
D- Probenecid decreases the secretion of uric acid

C- Probenecid decreases reabsorption of uric acid- Although probenecid decreases secretion of urate in renal tubules, its most effective action is inhibition of reabsorption of uric acid.
The correct answer is C

 

Question 10. Which of the following is considered a limiting adverse effect of ACE inhibitors?

A- Acidosis
B- Hyperkalemia
C- Hypokalemia
D- Hyponatremia

B- Hyperkalemia- ACE inhibitor intake leads to reduction of aldosterone levels which results in decreased K excretion. Limiting these drugs is considered in cases of hyperkalemia.
The correct answer is B

 

High-yield points from this set

  • Infliximab is a TNF-alpha antibody.
  • Tardive dyskinesia is the most serious irreversible side effect of typical antipsychotics.
  • Ursodiol dissolves cholesterol gallstones.
  • Labetalol blocks alpha-1 and beta receptors.

Keep practicing

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