Drug interactions
Diphenhydramine + Pregabalin
Severity: Moderate
Diphenhydramine and Pregabalin: 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
Both agents depress the central nervous system, so combined use can cause marked drowsiness, dizziness and impaired coordination. Respiratory depression has been reported with pregabalin plus other CNS depressants, mainly in vulnerable patients.
What this interaction means in plain words
Diphenhydramine and Pregabalin 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 belongs to Respiratory; Pregabalin belongs to Central Nervous System.
Why it happens
Additive CNS depression from pregabalin and the sedating first-generation antihistamine.
What to do
Prefer the lowest effective doses and avoid routine use of diphenhydramine as a sleep aid in patients taking pregabalin. Monitor for sedation, falls and respiratory depression, particularly in older adults.
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 Pregabalin
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Pregabalin?
MediHelp rates the interaction as moderate. Diphenhydramine and Pregabalin 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. Both agents depress the central nervous system, so combined use can cause marked drowsiness, dizziness and impaired coordination. Respiratory depression has been reported with pregabalin plus other CNS depressants, mainly in vulnerable patients.
How serious is the interaction between Diphenhydramine and Pregabalin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer the lowest effective doses and avoid routine use of diphenhydramine as a sleep aid in patients taking pregabalin. Monitor for sedation, falls and respiratory depression, particularly in older adults.
What other medicines interact with Pregabalin?
MediHelp also lists interactions of Pregabalin with, for example, Alprazolam, Amobarbital, Belladonna and opium. The full list is on the Pregabalin page.
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