Drug interactions
Diphenhydramine + Propranolol
Severity: Minor
Diphenhydramine and Propranolol: minor 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
Diphenhydramine inhibits CYP2D6 and may raise propranolol concentrations. The clinical effect is usually modest, but heart rate and blood pressure may fall further.
What this interaction means in plain words
Diphenhydramine and Propranolol have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Diphenhydramine belongs to Respiratory; Propranolol belongs to Cardiovascular.
Why it happens
Diphenhydramine inhibits CYP2D6, reducing propranolol metabolism.
What to do
No routine adjustment is needed; monitor heart rate and blood pressure if diphenhydramine is used regularly.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Propranolol
- Propranolol + Thioridazine Contraindicated
- Acebutolol + Propranolol Major
- Adrenaline-articaine + Propranolol Major
- Amifostine + Propranolol Major
- Amiodarone + Propranolol Major
- Arformoterol + Propranolol Major
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Propranolol?
MediHelp rates the interaction as minor. Diphenhydramine and Propranolol have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Diphenhydramine inhibits CYP2D6 and may raise propranolol concentrations. The clinical effect is usually modest, but heart rate and blood pressure may fall further.
How serious is the interaction between Diphenhydramine and Propranolol?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine adjustment is needed; monitor heart rate and blood pressure if diphenhydramine is used regularly.
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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