Psychopharmacology: smoking and clozapine: 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 · Psychopharmacology: smoking and clozapine

Sample item

A patient on a stable dose of olanzapine stops smoking after admission to a non-smoking ward and becomes sedated. Why?

ANicotine inhibits metabolismBOlanzapine becomes more protein boundCLoss of CYP1A2 induction by tobacco smoke raises drug levelsDSmoking increases the half-life of the drug

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

The answer and the reasoning

C. Loss of CYP1A2 induction by tobacco smoke raises drug levels

Polycyclic hydrocarbons in tobacco smoke (not nicotine) induce CYP1A2, lowering levels of clozapine, olanzapine, caffeine and theophylline. Stopping smoking removes this induction, so levels rise within days to weeks and dose reduction is needed.

Option by option

A. Nicotine inhibits metabolism
Nicotine does not inhibit this metabolism.
B. Olanzapine becomes more protein bound
Protein binding is not the explanation.
C. Loss of CYP1A2 induction by tobacco smoke raises drug levels (correct)
Correct. Cessation removes CYP1A2 induction.
D. Smoking increases the half-life of the drug
Smoking shortens, not lengthens, the half-life of these drugs.

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, Loss of CYP1A2 induction by tobacco smoke raises drug levels. Polycyclic hydrocarbons in tobacco smoke (not nicotine) induce CYP1A2, lowering levels of clozapine, olanzapine, caffeine and theophylline.

Why is "Nicotine inhibits metabolism" not the answer?

Nicotine does not inhibit this metabolism.

Why is "Olanzapine becomes more protein bound" not the answer?

Protein binding is not the explanation.

Why is "Smoking increases the half-life of the drug" not the answer?

Smoking shortens, not lengthens, the half-life of these drugs.

What concept does this question test?

It tests Psychopharmacology: smoking and clozapine in Psychiatry. Stopping smoking removes this induction, so levels rise within days to weeks and dose reduction is needed.

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 Psychopharmacology: smoking and clozapine?

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.