Drug interactions
Brexpiprazole + Diphenhydramine
Severity: Moderate
Brexpiprazole and Diphenhydramine: 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
Diphenhydramine is sedating and a moderate CYP2D6 inhibitor, whereas brexpiprazole is cleared partly by CYP2D6. The combination may increase sedation and could raise brexpiprazole exposure, especially if a CYP3A4 inhibitor is also present.
What this interaction means in plain words
Brexpiprazole and Diphenhydramine 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.
Brexpiprazole belongs to Central Nervous System; Diphenhydramine belongs to Respiratory.
Why it happens
Additive CNS depression plus CYP2D6 inhibition by diphenhydramine reducing brexpiprazole clearance.
What to do
Monitor for sedation and brexpiprazole adverse effects, and limit diphenhydramine use. Halve or reduce the brexpiprazole dose per labeling if combined with both CYP2D6 and CYP3A4 inhibitors.
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 Brexpiprazole
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Brexpiprazole with Diphenhydramine?
MediHelp rates the interaction as moderate. Brexpiprazole and Diphenhydramine 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. Diphenhydramine is sedating and a moderate CYP2D6 inhibitor, whereas brexpiprazole is cleared partly by CYP2D6. The combination may increase sedation and could raise brexpiprazole exposure, especially if a CYP3A4 inhibitor is also present.
How serious is the interaction between Brexpiprazole and Diphenhydramine?
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 for sedation and brexpiprazole adverse effects, and limit diphenhydramine use. Halve or reduce the brexpiprazole dose per labeling if combined with both CYP2D6 and CYP3A4 inhibitors.
What other medicines interact with Brexpiprazole?
MediHelp also lists interactions of Brexpiprazole with, for example, Alfentanil, Amisulpride, Apalutamide. The full list is on the Brexpiprazole page.
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