Drug interactions
Fluphenazine + Marijuana
Severity: Moderate
Fluphenazine 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
Cannabis causes sedation and impaired cognition, and may add to fluphenazine's sedative and anticholinergic effects. Combined use may also worsen tachycardia, orthostatic hypotension and psychotic symptoms in some patients.
What this interaction means in plain words
Fluphenazine 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 central nervous system depression and cardiovascular effects; cannabinoids may also influence CYP-mediated metabolism.
What to do
Advise patients to avoid cannabis, particularly while psychosis is being treated. Monitor sedation, blood pressure, heart rate and psychiatric status if use continues.
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 Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
Frequently asked questions
Can I take Fluphenazine with Marijuana?
MediHelp rates the interaction as moderate. Fluphenazine 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. Cannabis causes sedation and impaired cognition, and may add to fluphenazine's sedative and anticholinergic effects. Combined use may also worsen tachycardia, orthostatic hypotension and psychotic symptoms in some patients.
How serious is the interaction between Fluphenazine 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: Advise patients to avoid cannabis, particularly while psychosis is being treated. Monitor sedation, blood pressure, heart rate and psychiatric status if use continues.
What other medicines interact with Fluphenazine?
MediHelp also lists interactions of Fluphenazine with, for example, Arsenic trioxide, Dofetilide, Ibutilide. The full list is on the Fluphenazine page.
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