Drug interactions
Ivacaftor + Phenobarbitone
Severity: Major
Ivacaftor and Phenobarbitone: 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
Phenobarbital induces CYP3A and is expected to substantially lower ivacaftor exposure, risking loss of CFTR potentiation.
What this interaction means in plain words
Ivacaftor and Phenobarbitone 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.
Ivacaftor belongs to Miscellaneous; Phenobarbitone belongs to Central Nervous System.
Why it happens
CYP3A induction by phenobarbital accelerates ivacaftor clearance.
What to do
Avoid coadministration; select a non-inducing anticonvulsant where possible.
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 Ivacaftor
- Ensitrelvir + Ivacaftor Contraindicated
- Apalutamide + Ivacaftor Major
- Carbamazepine + Ivacaftor Major
- Clarithromycin + Ivacaftor Major
- Efavirenz + Ivacaftor Major
- Enzalutamide + Ivacaftor Major
Other interactions of Phenobarbitone
- Cabotegravir + Phenobarbitone Contraindicated
- Doravirine + Phenobarbitone Contraindicated
- Isavuconazole + Phenobarbitone Contraindicated
- Darolutamide + Phenobarbitone Major
- Finerenone + Phenobarbitone Major
- Letermovir + Phenobarbitone Major
Frequently asked questions
Can I take Ivacaftor with Phenobarbitone?
MediHelp rates the interaction as major. Ivacaftor and Phenobarbitone 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. Phenobarbital induces CYP3A and is expected to substantially lower ivacaftor exposure, risking loss of CFTR potentiation.
How serious is the interaction between Ivacaftor and Phenobarbitone?
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 coadministration; select a non-inducing anticonvulsant where possible.
What other medicines interact with Ivacaftor?
MediHelp also lists interactions of Ivacaftor with, for example, Ensitrelvir, Apalutamide, Carbamazepine. The full list is on the Ivacaftor page.
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