Drug interactions
Cabotegravir + Phenobarbitone
Severity: Contraindicated
Cabotegravir and Phenobarbitone: contraindicated 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 is expected to reduce cabotegravir exposure to subtherapeutic levels. This risks virologic failure and resistance, especially with long-acting formulations that cannot be quickly adjusted.
What this interaction means in plain words
Cabotegravir and Phenobarbitone are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Cabotegravir belongs to Anti Virals; Phenobarbitone belongs to Central Nervous System.
Why it happens
Phenobarbital induces UGT1A1 and other metabolic enzymes, increasing cabotegravir clearance.
What to do
Avoid the combination and use an alternative anticonvulsant or antiretroviral. Account for prolonged induction after phenobarbital is discontinued.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Cabotegravir
- Apalutamide + Cabotegravir Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Cabotegravir + Oxcarbazepine Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Cabotegravir + Rifabutin Contraindicated
- Cabotegravir + Rifampicin Contraindicated
Other interactions of Phenobarbitone
- Doravirine + Phenobarbitone Contraindicated
- Isavuconazole + Phenobarbitone Contraindicated
- Darolutamide + Phenobarbitone Major
- Finerenone + Phenobarbitone Major
- Ivacaftor + Phenobarbitone Major
- Letermovir + Phenobarbitone Major
Frequently asked questions
Can I take Cabotegravir with Phenobarbitone?
MediHelp rates the interaction as contraindicated. Cabotegravir and Phenobarbitone are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Phenobarbital is expected to reduce cabotegravir exposure to subtherapeutic levels. This risks virologic failure and resistance, especially with long-acting formulations that cannot be quickly adjusted.
How serious is the interaction between Cabotegravir and Phenobarbitone?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and use an alternative anticonvulsant or antiretroviral. Account for prolonged induction after phenobarbital is discontinued.
What other medicines interact with Cabotegravir?
MediHelp also lists interactions of Cabotegravir with, for example, Apalutamide, Carbamazepine, Oxcarbazepine. The full list is on the Cabotegravir page.
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