Drug interactions
Brexanolone + Diphenhydramine
Severity: Major
Brexanolone and Diphenhydramine: major 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
Brexanolone causes excessive sedation and sudden loss of consciousness in some patients. Diphenhydramine adds CNS depression, which may increase this risk.
What this interaction means in plain words
Brexanolone and Diphenhydramine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Additive CNS depression; brexanolone is a positive GABA-A modulator and diphenhydramine blocks H1 receptors.
What to do
Avoid starting sedating antihistamines during a brexanolone infusion where possible. Continue the monitoring required during infusion, including pulse oximetry, and reduce or interrupt the dose if sedation is excessive.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Diphenhydramine
Frequently asked questions
Can I take Brexanolone with Diphenhydramine?
MediHelp rates the interaction as major. Brexanolone and Diphenhydramine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Brexanolone causes excessive sedation and sudden loss of consciousness in some patients. Diphenhydramine adds CNS depression, which may increase this risk.
How serious is the interaction between Brexanolone and Diphenhydramine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid starting sedating antihistamines during a brexanolone infusion where possible. Continue the monitoring required during infusion, including pulse oximetry, and reduce or interrupt the dose if sedation is excessive.
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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