Drug interactions
Carvedilol + Phenobarbital
Severity: Moderate
Carvedilol and Phenobarbital: moderate 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 a broad enzyme inducer and may reduce carvedilol exposure, weakening its blood pressure and heart rate control. Effects may take days to weeks to develop and reverse after phenobarbital is stopped.
What this interaction means in plain words
Carvedilol and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Phenobarbital induces hepatic CYP enzymes and increases carvedilol clearance.
What to do
Monitor blood pressure and heart rate and titrate carvedilol upward if needed; lower the dose again if phenobarbital is discontinued.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Carvedilol
Frequently asked questions
Can I take Carvedilol with Phenobarbital?
MediHelp rates the interaction as moderate. Carvedilol and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Phenobarbital is a broad enzyme inducer and may reduce carvedilol exposure, weakening its blood pressure and heart rate control. Effects may take days to weeks to develop and reverse after phenobarbital is stopped.
How serious is the interaction between Carvedilol and Phenobarbital?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure and heart rate and titrate carvedilol upward if needed; lower the dose again if phenobarbital is discontinued.
What other medicines interact with Carvedilol?
MediHelp also lists interactions of Carvedilol with, for example, Amifostine, Amiodarone, Arformoterol. The full list is on the Carvedilol page.
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