Drug interactions
Primidone + Rivaroxaban
Severity: Major
Primidone and Rivaroxaban: major interaction.
Last updated Sources: UK SmPC
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, an enzyme inducer, and may lower rivaroxaban levels, risking subtherapeutic anticoagulation and thromboembolism.
What this interaction means in plain words
Primidone and Rivaroxaban 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 belongs to Central Nervous System; Rivaroxaban belongs to Cardiovascular.
Why it happens
Induction of CYP3A4 and P-glycoprotein by primidone and its phenobarbital metabolite increases rivaroxaban clearance.
What to do
Avoid combined use where possible and consider a non-inducing anticonvulsant or a different anticoagulant with INR monitoring. If unavoidable, monitor for thromboembolic events.
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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References
Other interactions of Rivaroxaban
- Defibrotide + Rivaroxaban Contraindicated
- Ketoconazole + Rivaroxaban Contraindicated
- Ketorolac + Rivaroxaban Contraindicated
- Abciximab + Rivaroxaban Major
- Acalabrutinib + Rivaroxaban Major
- Acetylsalicylic acid + Rivaroxaban 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 Primidone with Rivaroxaban?
MediHelp rates the interaction as major. Primidone and Rivaroxaban 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, an enzyme inducer, and may lower rivaroxaban levels, risking subtherapeutic anticoagulation and thromboembolism.
How serious is the interaction between Primidone and Rivaroxaban?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combined use where possible and consider a non-inducing anticonvulsant or a different anticoagulant with INR monitoring. If unavoidable, monitor for thromboembolic events.
What other medicines interact with Rivaroxaban?
MediHelp also lists interactions of Rivaroxaban with, for example, Defibrotide, Ketoconazole, Ketorolac. The full list is on the Rivaroxaban page.
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