Sex hormone drugs: GnRH agonist flare: 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 drugs: GnRH agonist flare

Sample item

A 68-year-old man with metastatic prostate cancer involving the lumbar spine is about to start leuprolide. Which precaution prevents a harmful early event, and why?

AGive a 5-alpha reductase inhibitor to prevent bone painBGive leuprolide with testosterone to prevent hypogonadismCStart a GnRH antagonist and a GnRH agonist togetherDStart an antiandrogen such as bicalutamide before and with leuprolide, to block the initial testosterone surge

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

The answer and the reasoning

D. Start an antiandrogen such as bicalutamide before and with leuprolide, to block the initial testosterone surge

A GnRH agonist initially stimulates LH release and causes a transient rise in testosterone for one to two weeks before pituitary desensitisation lowers it. In metastatic disease this flare can worsen bone pain, urinary obstruction or cord compression. An antiandrogen started a week before and continued for some weeks blocks the receptor effect.

Option by option

A. Give a 5-alpha reductase inhibitor to prevent bone pain
A 5-alpha reductase inhibitor does not prevent the flare in metastatic disease and is not part of this protocol.
B. Give leuprolide with testosterone to prevent hypogonadism
Giving testosterone would feed the tumour and worsen the disease.
C. Start a GnRH antagonist and a GnRH agonist together
Combining agonists and antagonists is not the standard flare precaution; antagonists such as degarelix act without a surge alone.
D. Start an antiandrogen such as bicalutamide before and with leuprolide, to block the initial testosterone surge (correct)
An antiandrogen blocks androgen receptors during the early testosterone surge.

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 D, Start an antiandrogen such as bicalutamide before and with leuprolide, to block the initial testosterone surge. A GnRH agonist initially stimulates LH release and causes a transient rise in testosterone for one to two weeks before pituitary desensitisation lowers it.

Why is "Give a 5-alpha reductase inhibitor to prevent bone pain" not the answer?

A 5-alpha reductase inhibitor does not prevent the flare in metastatic disease and is not part of this protocol.

Why is "Give leuprolide with testosterone to prevent hypogonadism" not the answer?

Giving testosterone would feed the tumour and worsen the disease.

Why is "Start a GnRH antagonist and a GnRH agonist together" not the answer?

Combining agonists and antagonists is not the standard flare precaution; antagonists such as degarelix act without a surge alone.

What concept does this question test?

It tests Sex hormone drugs: GnRH agonist flare in Pharmacology. In metastatic disease this flare can worsen bone pain, urinary obstruction or cord compression. An antiandrogen started a week before and continued for some weeks blocks the receptor 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 drugs: GnRH agonist flare?

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.