Drug interactions
Armodafinil + Diphenhydramine
Severity: Minor
Armodafinil and Diphenhydramine: 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 causes marked sedation, while armodafinil promotes wakefulness. Antihistamine sedation may counteract the benefit of armodafinil, and the net effect varies between patients.
What this interaction means in plain words
Armodafinil and Diphenhydramine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Armodafinil belongs to Central Nervous System; Diphenhydramine belongs to Respiratory.
Why it happens
Opposing pharmacodynamic effects on CNS arousal (H1 antagonism versus wake promotion).
What to do
Avoid regular use of sedating antihistamines in patients treated for sleepiness; use a non-sedating alternative if an antihistamine is needed.
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 Armodafinil
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Armodafinil with Diphenhydramine?
MediHelp rates the interaction as minor. Armodafinil and Diphenhydramine 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 causes marked sedation, while armodafinil promotes wakefulness. Antihistamine sedation may counteract the benefit of armodafinil, and the net effect varies between patients.
How serious is the interaction between Armodafinil and Diphenhydramine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid regular use of sedating antihistamines in patients treated for sleepiness; use a non-sedating alternative if an antihistamine is needed.
What other medicines interact with Armodafinil?
MediHelp also lists interactions of Armodafinil with, for example, Avapritinib, Elacestrant, Elbasvir / grazoprevir. The full list is on the Armodafinil page.
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