Cardiovascular drugs: aspirin and platelet life span: practice question

A Pharmacology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Pharmacology · Cardiovascular drugs: aspirin and platelet life span

Sample item

A man taking low-dose aspirin is planned for elective surgery with a high bleeding risk. He is told to stop aspirin about a week before. What is the reason for the interval?

APlatelets cannot make new COX-1 enzymeBAspirin accumulates in body fat tissueCHepatic enzymes need a week to clear itDAspirin has a plasma half-life of seven days

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Platelets cannot make new COX-1 enzyme

Aspirin irreversibly acetylates platelet COX-1, and anucleate platelets cannot synthesise more. Function returns only as new platelets enter the circulation, at about 10 percent per day, so roughly 7 to 10 days are needed.

Option by option

A. Platelets cannot make new COX-1 enzyme (correct)
Correct. Platelets lack a nucleus, so the block lasts for the platelet life span.
B. Aspirin accumulates in body fat tissue
Aspirin does not accumulate in fat.
C. Hepatic enzymes need a week to clear it
Aspirin is cleared quickly, so the delay is not due to hepatic clearance.
D. Aspirin has a plasma half-life of seven days
Aspirin is cleared in hours, so the plasma half-life is not the reason.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is A, Platelets cannot make new COX-1 enzyme. Aspirin irreversibly acetylates platelet COX-1, and anucleate platelets cannot synthesise more.

Why is "Aspirin accumulates in body fat tissue" not the answer?

Aspirin does not accumulate in fat.

Why is "Hepatic enzymes need a week to clear it" not the answer?

Aspirin is cleared quickly, so the delay is not due to hepatic clearance.

Why is "Aspirin has a plasma half-life of seven days" not the answer?

Aspirin is cleared in hours, so the plasma half-life is not the reason.

What concept does this question test?

It tests Cardiovascular drugs: aspirin and platelet life span in Pharmacology. Function returns only as new platelets enter the circulation, at about 10 percent per day, so roughly 7 to 10 days are needed.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Cardiovascular drugs: aspirin and platelet life span?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.