Drug interactions
Oxycodone + Primidone
Severity: Major
Oxycodone and Primidone: major 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 is metabolized to phenobarbital, which adds CNS and respiratory depression to opioid effects. Phenobarbital also induces CYP3A4, which can lower oxycodone concentrations and reduce analgesia.
What this interaction means in plain words
Oxycodone and Primidone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Oxycodone belongs to Musculoskeletal; Primidone belongs to Central Nervous System.
Why it happens
Additive CNS depression plus CYP3A4 induction by primidone and its metabolite phenobarbital.
What to do
Monitor sedation, respiratory rate and pain control and titrate oxycodone to effect. Reassess the dose if primidone is started, changed or stopped.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Oxycodone
- Alvimopan + Oxycodone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Oxycodone Contraindicated
- Isocarboxazid + Oxycodone Contraindicated
- Olanzapine / samidorphan + Oxycodone Contraindicated
- Oxycodone + Phenelzine Contraindicated
- Oxycodone + Sodium oxybate Contraindicated
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 Oxycodone with Primidone?
MediHelp rates the interaction as major. Oxycodone and Primidone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Primidone is metabolized to phenobarbital, which adds CNS and respiratory depression to opioid effects. Phenobarbital also induces CYP3A4, which can lower oxycodone concentrations and reduce analgesia.
How serious is the interaction between Oxycodone and Primidone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor sedation, respiratory rate and pain control and titrate oxycodone to effect. Reassess the dose if primidone is started, changed or stopped.
What other medicines interact with Oxycodone?
MediHelp also lists interactions of Oxycodone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Isocarboxazid. The full list is on the Oxycodone page.
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