Substance use: starting naltrexone in opioid dependence: practice question

A Psychiatry 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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Psychiatry · Substance use: starting naltrexone in opioid dependence

Sample item

A man dependent on heroin has completed detoxification and wishes to start oral naltrexone for relapse prevention. His last heroin use was two days ago. What is the safest approach?

AStart a half dose now and increase gradually over a weekBStart it today and give clonidine to prevent any withdrawalCConfirm he is opioid-free for 7 to 10 days, ideally with a negative naloxone challengeDStart it today and add low-dose methadone to cover discomfort

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

The answer and the reasoning

C. Confirm he is opioid-free for 7 to 10 days, ideally with a negative naloxone challenge

Naltrexone is a full opioid antagonist and will precipitate severe withdrawal if any opioid is still occupying receptors. The patient should be free of short-acting opioids for 7 to 10 days, confirmed by history, urine tests or a naloxone challenge, before it is started.

Option by option

A. Start a half dose now and increase gradually over a week
A reduced dose can still displace opioids from receptors and precipitate withdrawal, so starting too early is unsafe.
B. Start it today and give clonidine to prevent any withdrawal
Clonidine does not prevent precipitated withdrawal, so the timing problem remains.
C. Confirm he is opioid-free for 7 to 10 days, ideally with a negative naloxone challenge (correct)
Correct. Waiting until he is opioid-free avoids precipitated withdrawal.
D. Start it today and add low-dose methadone to cover discomfort
Methadone would be blocked by naltrexone and contradicts the aim of antagonist therapy.

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 Psychiatry question

What is the answer to this Psychiatry question?

The best answer is C, Confirm he is opioid-free for 7 to 10 days, ideally with a negative naloxone challenge. Naltrexone is a full opioid antagonist and will precipitate severe withdrawal if any opioid is still occupying receptors.

Why is "Start a half dose now and increase gradually over a week" not the answer?

A reduced dose can still displace opioids from receptors and precipitate withdrawal, so starting too early is unsafe.

Why is "Start it today and give clonidine to prevent any withdrawal" not the answer?

Clonidine does not prevent precipitated withdrawal, so the timing problem remains.

Why is "Start it today and add low-dose methadone to cover discomfort" not the answer?

Methadone would be blocked by naltrexone and contradicts the aim of antagonist therapy.

What concept does this question test?

It tests Substance use: starting naltrexone in opioid dependence in Psychiatry. The patient should be free of short-acting opioids for 7 to 10 days, confirmed by history, urine tests or a naloxone challenge, before it is started.

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 Substance use: starting naltrexone in opioid dependence?

Learn each diagnosis by its core features and its first-line treatment. Then use the flashcards and the other Psychiatry 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.