Repeated USMLE Questions- Pharmacology- 272

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Q- 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.



Q- 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.




Q- 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. 



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3 thoughts on “Repeated USMLE Questions- Pharmacology- 272”

  1. Tnx

  2. Thank you so much Dr. Nazmul.

  3. Grateful for the explanations.

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