Drug interactions
Ketamine + Methadone
Severity: Moderate
Ketamine 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
Ketamine combined with methadone produces additive CNS and respiratory depression. Sedation, reduced responsiveness and impaired breathing are more likely, especially at higher doses or in opioid-naive patients.
What this interaction means in plain words
Ketamine 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.
Ketamine belongs to Central Nervous System; Methadone belongs to Musculoskeletal.
Why it happens
Additive CNS depressant effects of an opioid agonist and an NMDA antagonist anesthetic.
What to do
Monitor sedation level, respiratory rate and oxygen saturation, and use the lowest effective doses of each drug. Ensure monitoring equipment and naloxone are available when ketamine is given at anesthetic doses.
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 Ketamine
Frequently asked questions
Can I take Ketamine with Methadone?
MediHelp rates the interaction as moderate. Ketamine 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. Ketamine combined with methadone produces additive CNS and respiratory depression. Sedation, reduced responsiveness and impaired breathing are more likely, especially at higher doses or in opioid-naive patients.
How serious is the interaction between Ketamine 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 sedation level, respiratory rate and oxygen saturation, and use the lowest effective doses of each drug. Ensure monitoring equipment and naloxone are available when ketamine is given at anesthetic doses.
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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