8 USMLE Pharmacology Quick Review Questions with Answers (Set 45)

These 8 quick USMLE pharmacology review questions test high-yield facts that show up again and again on the exam, including Propranolol, Benzodiazepines, Phenoxybenzamine before beta-blocker, Nafcillin, Methotrexate. 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. A 28-year-old woman presents with palpitations and tremor. ECG shows atrial fibrillation. Labs reveal suppressed TSH and elevated T4. What is the most appropriate initial treatment?

A- Methimazole
B- Propranolol
C- Radioactive iodine therapy
D- Thyroidectomy

B- Propranolol- In hyperthyroidism with atrial fibrillation, the first step is beta-blocker therapy to control adrenergic symptoms and heart rate before definitive therapy.
The correct answer is B

 

Question 2. A 30-year-old woman presents with severe unilateral headache, nausea, and photophobia. She has experienced similar episodes in the past. Neurologic examination is normal. What is the most appropriate acute treatment?

A- Acetaminophen
B- Propranolol
C- Sumatriptan
D- Topiramate

C- Sumatriptan-Triptans are first-line therapy for acute migraine attacks. Beta-blockers and topiramate are used for migraine prevention.
The correct answer is C

 

Question 3. A drug that increases GABA activity in the central nervous system is prescribed for anxiety. Which class of drugs acts by increasing the frequency of chloride channel opening at the GABA-A receptor?

A- Barbiturates
B- Benzodiazepines
C- Selective serotonin reuptake inhibitors
D- Tricyclic antidepressants

B- Benzodiazepines- Benzodiazepines increase the frequency of chloride channel opening at GABA-A receptors, enhancing inhibitory neurotransmission.
The correct answer is B

 

Question 4. A 40-year-old man presents with severe hypertension, palpitations, headaches, and diaphoresis. CT scan reveals an adrenal mass. What is the best preoperative management?

A- Beta-blocker before alpha-blocker
B- Immediate surgery without medications
C- Intravenous nitroglycerin only
D- Phenoxybenzamine before the beta-blocker

D- Phenoxybenzamine before beta-blocker- In pheochromocytoma, alpha blockade must be started before beta blockade to prevent a hypertensive crisis. Blocking beta receptors first removes beta-2 vasodilation and leaves the catecholamines acting on alpha-1 receptors unopposed, causing severe vasoconstriction. Phenoxybenzamine is given for about 10–14 days, then a beta-blocker is added to control tachycardia before surgery.
The correct answer is D

 

Question 5. A patient is prescribed heparin. Which one of the following laboratory tests is used to monitor its effectiveness?

A- Bleeding time
B- International normalized ratio (INR)
C- Platelet count
D- Partial thromboplastin time (PTT)

D- Partial thromboplastin time (PTT)- Heparin prolongs partial thromboplastin time (PTT) and is monitored using this test. INR is used to monitor warfarin’s effect.
The correct answer is D

 

Question 6. A 54-year-old woman is admitted with severe community-acquired pneumonia. 48 hours later, blood cultures grow methicillin-sensitive Staphylococcus aureus (MSSA). Which one of the following antibiotics is preferred?

A- Cefepime
B- Nafcillin
C- Vancomycin
D- Piperacillin-tazobactam

B- Nafcillin- Nafcillin is preferred for MSSA bacteremia because it is more effective than vancomycin for methicillin-sensitive strains.
The correct answer is B

 

Question 7. Which one of the following classes of drugs decreases preload by increasing venous capacitance?

A- ACE inhibitors
B- Beta blockers
C- Nitrates
D- Thiazide diuretics

C- Nitrates cause dilatation of veins, which decreases preload, leading to reduced cardiac workload.
The correct answer is C

 

Question 8. A 65-year-old woman with long-standing rheumatoid arthritis presents with progressive shortness of breath and dry cough. Chest X-ray shows bilateral interstitial infiltrates. Which of the following medications is most likely responsible?

A- Etanercept
B- Hydroxychloroquine
C- Methotrexate
D- Prednisone

C- Methotrexate- Methotrexate can cause pulmonary fibrosis and pneumonitis as an adverse effect, leading to restrictive lung disease. Symptoms improve with discontinuation of the drug.
The correct answer is C

 

High-yield points from this set

  • In hyperthyroidism with atrial fibrillation, the first step is beta-blocker therapy to control adrenergic symptoms and heart rate before definitive therapy.
  • Triptans are first-line therapy for acute migraine attacks.
  • Benzodiazepines increase the frequency of chloride channel opening at GABA-A receptors, enhancing inhibitory neurotransmission.
  • blocker- In pheochromocytoma, alpha blockade must be initiated before beta blockade to prevent a hypertensive crisis.
  • Heparin prolongs partial thromboplastin time (PTT) and is monitored using this test.

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