Drug interactions
Diclofenac + Primidone
Severity: Minor
Diclofenac and Primidone: minor 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, and its metabolite phenobarbital, can induce hepatic enzymes and may lower diclofenac exposure. The clinical effect is probably small and may show up as reduced analgesic or anti-inflammatory benefit.
What this interaction means in plain words
Diclofenac and Primidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Diclofenac belongs to Musculoskeletal; Primidone belongs to Central Nervous System.
Why it happens
Enzyme induction by primidone/phenobarbital may increase CYP2C9-mediated clearance of diclofenac.
What to do
No routine dose change is needed; if pain control is inadequate, reassess the diclofenac dose within its usual range or consider another analgesic.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Diclofenac
- Diclofenac + Ketorolac Contraindicated
- Diclofenac + Ketorolac intranasal Contraindicated
- Aceclofenac + Diclofenac Major
- Acemetacin + Diclofenac Major
- Alteplase + Diclofenac Major
- Amiloride + Diclofenac Major
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 Diclofenac with Primidone?
MediHelp rates the interaction as minor. Diclofenac and Primidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Primidone, and its metabolite phenobarbital, can induce hepatic enzymes and may lower diclofenac exposure. The clinical effect is probably small and may show up as reduced analgesic or anti-inflammatory benefit.
How serious is the interaction between Diclofenac and Primidone?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose change is needed; if pain control is inadequate, reassess the diclofenac dose within its usual range or consider another analgesic.
What other medicines interact with Diclofenac?
MediHelp also lists interactions of Diclofenac with, for example, Ketorolac, Ketorolac intranasal, Aceclofenac. The full list is on the Diclofenac page.
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