Gynaecological endocrinology: hot flushes on tamoxifen: practice question

A OBG 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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OBG · Gynaecological endocrinology: hot flushes on tamoxifen

Sample item

A woman taking tamoxifen after breast cancer has troublesome hot flushes and cannot use systemic oestrogen. Which antidepressant is preferred because it spares the enzyme that activates tamoxifen?

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

The answer and the reasoning

B. Venlafaxine

Tamoxifen is converted to its active metabolite endoxifen by CYP2D6. Paroxetine, fluoxetine and bupropion strongly inhibit CYP2D6 and may blunt tamoxifen's effect, whereas venlafaxine is a weak inhibitor and reduces vasomotor symptoms.

Option by option

  • A. Fluoxetine

    Fluoxetine is a potent CYP2D6 inhibitor and is avoided with tamoxifen.

  • B. Venlafaxine (correct)

    Correct. Venlafaxine is a weak CYP2D6 inhibitor and eases hot flushes.

  • C. Paroxetine

    Paroxetine strongly inhibits CYP2D6 and lowers endoxifen formation.

  • D. Bupropion

    Bupropion strongly inhibits CYP2D6 and is also avoided with tamoxifen.

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.

More OBG questions

Questions about this OBG question

What is the answer to this OBG question?

The best answer is B, Venlafaxine. Tamoxifen is converted to its active metabolite endoxifen by CYP2D6.

Why is "Fluoxetine" not the answer?

Fluoxetine is a potent CYP2D6 inhibitor and is avoided with tamoxifen.

Why is "Paroxetine" not the answer?

Paroxetine strongly inhibits CYP2D6 and lowers endoxifen formation.

Why is "Bupropion" not the answer?

Bupropion strongly inhibits CYP2D6 and is also avoided with tamoxifen.

What concept does this question test?

It tests Gynaecological endocrinology: hot flushes on tamoxifen in OBG. Paroxetine, fluoxetine and bupropion strongly inhibit CYP2D6 and may blunt tamoxifen's effect, whereas venlafaxine is a weak inhibitor and reduces vasomotor symptoms.

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 Gynaecological endocrinology: hot flushes on tamoxifen?

Learn management algorithms as steps: PPH, eclampsia, ectopic pregnancy. Then use the flashcards and the other OBG 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.