Drug interactions
Phenobarbital + Sofosbuvir
Severity: Major
Phenobarbital and Sofosbuvir: 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 is an inducer of P-gp and other enzymes and may lower sofosbuvir exposure. Reduced exposure may cause loss of antiviral efficacy and virologic failure.
What this interaction means in plain words
Phenobarbital and Sofosbuvir 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.
Why it happens
Phenobarbital induces intestinal P-gp, reducing sofosbuvir absorption.
What to do
Avoid the combination; use an alternative anticonvulsant without inducing activity.
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 Sofosbuvir
Frequently asked questions
Can I take Phenobarbital with Sofosbuvir?
MediHelp rates the interaction as major. Phenobarbital and Sofosbuvir 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 is an inducer of P-gp and other enzymes and may lower sofosbuvir exposure. Reduced exposure may cause loss of antiviral efficacy and virologic failure.
How serious is the interaction between Phenobarbital and Sofosbuvir?
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 the combination; use an alternative anticonvulsant without inducing activity.
What other medicines interact with Sofosbuvir?
MediHelp also lists interactions of Sofosbuvir with, for example, Amiodarone, Apalutamide, Carbamazepine. The full list is on the Sofosbuvir page.
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