Drug interactions
Marijuana + Risperidone
Severity: Moderate
Marijuana and Risperidone: 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, impaired cognition and tachycardia, which can add to the sedative and orthostatic effects of risperidone. Cannabis use is also associated with worse psychotic symptoms in susceptible patients, which can undermine antipsychotic treatment.
What this interaction means in plain words
Marijuana and Risperidone 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 depressant and hypotensive effects; THC may also worsen psychosis.
What to do
Counsel patients to avoid cannabis and screen for use. Monitor for sedation, orthostasis and relapse of psychotic symptoms.
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 Risperidone
- Ibutilide + Risperidone Contraindicated
- Risperidone + Vandetanib Contraindicated
- Adagrasib + Risperidone Major
- Amiodarone + Risperidone Major
- Amisulpride + Risperidone Major
- Amoxapine + Risperidone Major
Frequently asked questions
Can I take Marijuana with Risperidone?
MediHelp rates the interaction as moderate. Marijuana and Risperidone 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, impaired cognition and tachycardia, which can add to the sedative and orthostatic effects of risperidone. Cannabis use is also associated with worse psychotic symptoms in susceptible patients, which can undermine antipsychotic treatment.
How serious is the interaction between Marijuana and Risperidone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Counsel patients to avoid cannabis and screen for use. Monitor for sedation, orthostasis and relapse of psychotic symptoms.
What other medicines interact with Risperidone?
MediHelp also lists interactions of Risperidone with, for example, Ibutilide, Vandetanib, Adagrasib. The full list is on the Risperidone page.
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