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Drug interactions

Cyclosporin + Primidone

Severity: Major

Cyclosporin and Primidone: 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, which induces CYP3A4 and lowers cyclosporine concentrations. Subtherapeutic cyclosporine can result in rejection or loss of disease control.

What this interaction means in plain words

Cyclosporin 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.

Cyclosporin belongs to Miscellaneous; Primidone belongs to Central Nervous System.

Evidence level: Moderate

Why it happens

Induction of CYP3A4 by primidone and its metabolite phenobarbital accelerates cyclosporine metabolism.

What to do

Monitor cyclosporine trough levels and increase the dose as needed, reducing it again when primidone is stopped. Consider a non-inducing antiepileptic.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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References

Frequently asked questions

Can I take Cyclosporin with Primidone?

MediHelp rates the interaction as major. Cyclosporin 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 induces CYP3A4 and lowers cyclosporine concentrations. Subtherapeutic cyclosporine can result in rejection or loss of disease control.

How serious is the interaction between Cyclosporin 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 cyclosporine trough levels and increase the dose as needed, reducing it again when primidone is stopped. Consider a non-inducing antiepileptic.

What other medicines interact with Cyclosporin?

MediHelp also lists interactions of Cyclosporin with, for example, Adenovirus types 4 and 7 live, Aliskiren, Bcg vaccine live. The full list is on the Cyclosporin page.

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