Drug interactions
Diphenhydramine + Epinephrine racemic
Severity: Minor
Diphenhydramine and Epinephrine racemic: 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
Racemic epinephrine is a sympathomimetic given by inhalation or injection and may counteract some of the sedation from diphenhydramine. Both are commonly used together in allergic reactions without significant problems.
What this interaction means in plain words
Diphenhydramine and Epinephrine racemic have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Pharmacodynamic opposition of adrenergic stimulation and antihistamine sedation; no pharmacokinetic interaction is established.
What to do
No dose change is needed. Monitor heart rate and blood pressure when given together.
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 Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Epinephrine racemic?
MediHelp rates the interaction as minor. Diphenhydramine and Epinephrine racemic have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Racemic epinephrine is a sympathomimetic given by inhalation or injection and may counteract some of the sedation from diphenhydramine. Both are commonly used together in allergic reactions without significant problems.
How serious is the interaction between Diphenhydramine and Epinephrine racemic?
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 dose change is needed. Monitor heart rate and blood pressure when given together.
What other medicines interact with Diphenhydramine?
MediHelp also lists interactions of Diphenhydramine with, for example, Alfentanil, Belladonna and opium, Benzhydrocodone / acetaminophen. The full list is on the Diphenhydramine page.
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