Drug interactions
Cannabidiol + Methadone
Severity: Moderate
Cannabidiol and Methadone: 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
Cannabidiol can raise methadone exposure, possibly leading to stronger opioid effects such as sedation and respiratory depression. Cannabidiol also adds its own sedative effect. The size of the pharmacokinetic change is uncertain.
What this interaction means in plain words
Cannabidiol and Methadone 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.
Cannabidiol belongs to Central Nervous System; Methadone belongs to Musculoskeletal.
Why it happens
Cannabidiol inhibits CYP2C19, CYP2B6 and CYP3A4 activity, which may reduce methadone metabolism, and has additive CNS depressant effects.
What to do
Monitor for sedation, respiratory depression and QT-related symptoms when starting or stopping cannabidiol. Reduce the methadone dose if signs of excess opioid effect appear.
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 Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
Other interactions of Cannabidiol
- Cannabidiol + Phenytoin Major
- Cannabidiol + Sodium valproate Major
- Cannabidiol + Tacrolimus Major
- Abiraterone + Cannabidiol Moderate
- Alogliptin-pioglitazone + Cannabidiol Moderate
- Amiodarone + Cannabidiol Moderate
Frequently asked questions
Can I take Cannabidiol with Methadone?
MediHelp rates the interaction as moderate. Cannabidiol and Methadone 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. Cannabidiol can raise methadone exposure, possibly leading to stronger opioid effects such as sedation and respiratory depression. Cannabidiol also adds its own sedative effect. The size of the pharmacokinetic change is uncertain.
How serious is the interaction between Cannabidiol and Methadone?
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 for sedation, respiratory depression and QT-related symptoms when starting or stopping cannabidiol. Reduce the methadone dose if signs of excess opioid effect appear.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
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