Drug interactions
Olanzapine + Tobacco use
Severity: Moderate
Olanzapine and Tobacco use: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Polycyclic aromatic hydrocarbons in tobacco smoke induce CYP1A2, increasing olanzapine clearance and lowering plasma levels in smokers. Stopping smoking can raise olanzapine concentrations and cause adverse effects.
What this interaction means in plain words
Olanzapine and Tobacco use can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Induction of CYP1A2 by smoke hydrocarbons increases olanzapine metabolism.
What to do
Monitor response and tolerability when smoking is started, stopped or substantially changed, and consider reducing the olanzapine dose after cessation.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Olanzapine
Frequently asked questions
Can I take Olanzapine with Tobacco use?
MediHelp rates the interaction as moderate. Olanzapine and Tobacco use can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Polycyclic aromatic hydrocarbons in tobacco smoke induce CYP1A2, increasing olanzapine clearance and lowering plasma levels in smokers. Stopping smoking can raise olanzapine concentrations and cause adverse effects.
How serious is the interaction between Olanzapine and Tobacco use?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor response and tolerability when smoking is started, stopped or substantially changed, and consider reducing the olanzapine dose after cessation.
What other medicines interact with Olanzapine?
MediHelp also lists interactions of Olanzapine with, for example, Amisulpride, Amoxapine, Apomorphine. The full list is on the Olanzapine page.
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