Drug interactions
Clozapine + Marijuana
Severity: Moderate
Clozapine and Marijuana: 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
Smoked cannabis may induce CYP1A2 through combustion products, which can lower clozapine levels. Cannabis also adds sedation, tachycardia and orthostatic effects, and may worsen psychosis.
What this interaction means in plain words
Clozapine and Marijuana 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
Additive CNS depression, with possible CYP1A2 induction by smoke lowering clozapine concentrations.
What to do
Ask about cannabis use and counsel on its psychiatric risks. Monitor clinical response and consider clozapine levels if use changes.
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 Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Marijuana?
MediHelp rates the interaction as moderate. Clozapine and Marijuana 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. Smoked cannabis may induce CYP1A2 through combustion products, which can lower clozapine levels. Cannabis also adds sedation, tachycardia and orthostatic effects, and may worsen psychosis.
How serious is the interaction between Clozapine and Marijuana?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Ask about cannabis use and counsel on its psychiatric risks. Monitor clinical response and consider clozapine levels if use changes.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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