Drug interactions
Ketamine + Primidone
Severity: Moderate
Ketamine and Primidone: 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
Primidone, a barbiturate-related anticonvulsant, has sedative effects that add to those of ketamine. Excess sedation and respiratory depression are possible. Primidone is also a CYP3A4 and CYP2B6 inducer that may lower ketamine exposure with chronic use.
What this interaction means in plain words
Ketamine and Primidone 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; Primidone belongs to Central Nervous System.
Why it happens
Additive CNS depression, with possible enzyme induction by primidone and its phenobarbital metabolite speeding ketamine clearance.
What to do
Monitor sedation and respiratory status and titrate ketamine to clinical effect rather than fixed dosing. Do not stop primidone abruptly because of seizure risk.
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 Ketamine
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Ketamine with Primidone?
MediHelp rates the interaction as moderate. Ketamine and Primidone 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. Primidone, a barbiturate-related anticonvulsant, has sedative effects that add to those of ketamine. Excess sedation and respiratory depression are possible. Primidone is also a CYP3A4 and CYP2B6 inducer that may lower ketamine exposure with chronic use.
How serious is the interaction between Ketamine and Primidone?
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 and respiratory status and titrate ketamine to clinical effect rather than fixed dosing. Do not stop primidone abruptly because of seizure risk.
What other medicines interact with Ketamine?
MediHelp also lists interactions of Ketamine with, for example, Benzhydrocodone / acetaminophen, Brexanolone, Buprenorphine buccal. The full list is on the Ketamine page.
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