Drug interactions
Buprenorphine subdermal implant + Diphenhydramine
Severity: Moderate
Buprenorphine subdermal implant 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 a sedating antihistamine, and buprenorphine is an opioid that depresses the central nervous system. Taken together they can cause additive drowsiness, impaired psychomotor performance and, less commonly, respiratory depression. Systemic exposure from the implant is steady and low, so the effect is usually modest.
What this interaction means in plain words
Buprenorphine subdermal implant 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.
Why it happens
Additive central nervous system depression through opioid receptor agonism and central histamine H1 blockade.
What to do
Monitor for excessive sedation and slowed breathing, particularly after starting or raising the antihistamine dose. Advise patients to avoid driving and to limit other sedatives.
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 Diphenhydramine
Frequently asked questions
Can I take Buprenorphine subdermal implant with Diphenhydramine?
MediHelp rates the interaction as moderate. Buprenorphine subdermal implant 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 a sedating antihistamine, and buprenorphine is an opioid that depresses the central nervous system. Taken together they can cause additive drowsiness, impaired psychomotor performance and, less commonly, respiratory depression. Systemic exposure from the implant is steady and low, so the effect is usually modest.
How serious is the interaction between Buprenorphine subdermal implant 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 excessive sedation and slowed breathing, particularly after starting or raising the antihistamine dose. Advise patients to avoid driving and to limit other sedatives.
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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