Drug interactions
Phenobarbital + Propranolol
Severity: Moderate
Phenobarbital and Propranolol: 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 induces hepatic enzymes and can lower propranolol plasma concentrations, weakening its effect. Reduced control of heart rate, blood pressure or angina may result.
What this interaction means in plain words
Phenobarbital and Propranolol 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
Induction of hepatic CYP enzymes increases propranolol metabolism.
What to do
Monitor heart rate and blood pressure and increase propranolol dose as needed, or consider a renally cleared beta-blocker such as atenolol.
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 Propranolol
- Propranolol + Thioridazine Contraindicated
- Acebutolol + Propranolol Major
- Adrenaline-articaine + Propranolol Major
- Albuterol + Propranolol Major
- Amifostine + Propranolol Major
- Amiodarone + Propranolol Major
Frequently asked questions
Can I take Phenobarbital with Propranolol?
MediHelp rates the interaction as moderate. Phenobarbital and Propranolol 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 induces hepatic enzymes and can lower propranolol plasma concentrations, weakening its effect. Reduced control of heart rate, blood pressure or angina may result.
How serious is the interaction between Phenobarbital and Propranolol?
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 heart rate and blood pressure and increase propranolol dose as needed, or consider a renally cleared beta-blocker such as atenolol.
What other medicines interact with Propranolol?
MediHelp also lists interactions of Propranolol with, for example, Thioridazine, Acebutolol, Adrenaline-articaine. The full list is on the Propranolol page.
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