Drug interactions
Cigarette smoking + Olanzapine
Severity: Moderate
Cigarette smoking and Olanzapine: 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, which increases olanzapine clearance and lowers plasma concentrations in smokers. Stopping smoking can raise levels and cause adverse effects such as sedation, while starting smoking may reduce efficacy.
What this interaction means in plain words
Cigarette smoking and Olanzapine 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 tobacco smoke increases olanzapine metabolism.
What to do
Monitor response and consider olanzapine dose adjustment, guided by levels if available, when smoking status changes. After smoking cessation, watch for sedation and other adverse effects and consider a dose reduction.
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 Cigarette smoking with Olanzapine?
MediHelp rates the interaction as moderate. Cigarette smoking and Olanzapine 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, which increases olanzapine clearance and lowers plasma concentrations in smokers. Stopping smoking can raise levels and cause adverse effects such as sedation, while starting smoking may reduce efficacy.
How serious is the interaction between Cigarette smoking and Olanzapine?
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 consider olanzapine dose adjustment, guided by levels if available, when smoking status changes. After smoking cessation, watch for sedation and other adverse effects and consider a dose reduction.
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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