Sex hormone modulators: aromatase inhibitors: 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 · Sex hormone modulators: aromatase inhibitors

Sample item

Why is an aromatase inhibitor such as anastrozole used alone only in postmenopausal women and not in premenopausal women with ER-positive breast cancer?

AIt is inactivated by high progesterone levelsBIt is metabolised too rapidly by the premenopausal liverCFalling oestrogen removes feedback inhibition, raising gonadotropins and ovarian aromatase activityDIt acts only on ovarian aromatase and not on peripheral aromatase

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

The answer and the reasoning

C. Falling oestrogen removes feedback inhibition, raising gonadotropins and ovarian aromatase activity

In postmenopausal women oestrogen comes mainly from peripheral aromatisation of adrenal androgens, which anastrozole blocks. In premenopausal women, lowering oestrogen removes negative feedback and raises FSH and LH, driving the ovary to increase aromatase and androgen substrate, which overcomes the inhibition. Ovarian suppression is needed alongside it. Bone loss is a major adverse effect.

Option by option

A. It is inactivated by high progesterone levels
Progesterone levels do not inactivate the drug.
B. It is metabolised too rapidly by the premenopausal liver
There is no accelerated hepatic clearance in premenopausal women.
C. Falling oestrogen removes feedback inhibition, raising gonadotropins and ovarian aromatase activity (correct)
Correct. Loss of feedback increases gonadotropin drive and ovarian oestrogen output.
D. It acts only on ovarian aromatase and not on peripheral aromatase
Aromatase inhibitors block the enzyme in all tissues, including peripheral sites.

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 C, Falling oestrogen removes feedback inhibition, raising gonadotropins and ovarian aromatase activity. In postmenopausal women oestrogen comes mainly from peripheral aromatisation of adrenal androgens, which anastrozole blocks.

Why is "It is inactivated by high progesterone levels" not the answer?

Progesterone levels do not inactivate the drug.

Why is "It is metabolised too rapidly by the premenopausal liver" not the answer?

There is no accelerated hepatic clearance in premenopausal women.

Why is "It acts only on ovarian aromatase and not on peripheral aromatase" not the answer?

Aromatase inhibitors block the enzyme in all tissues, including peripheral sites.

What concept does this question test?

It tests Sex hormone modulators: aromatase inhibitors in Pharmacology. In premenopausal women, lowering oestrogen removes negative feedback and raises FSH and LH, driving the ovary to increase aromatase and androgen substrate, which overcomes the inhibition. Ovarian suppression is needed alongside it. Bone loss is a major adverse effect.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Sex hormone modulators: aromatase inhibitors?

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.