Drug interactions
Carisoprodol + Diphenhydramine
Severity: Moderate
Carisoprodol 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 strongly sedating antihistamine, and with carisoprodol it may cause marked drowsiness, impaired coordination and confusion, especially in older adults.
What this interaction means in plain words
Carisoprodol 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.
Carisoprodol belongs to Musculoskeletal; Diphenhydramine belongs to Respiratory.
Why it happens
Additive CNS depression via central H1 antagonism and carisoprodol's sedative action.
What to do
Advise against driving and alcohol, and consider a non-sedating antihistamine. Monitor older patients for confusion and falls.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Carisoprodol and Diphenhydramine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Carisoprodol
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Carisoprodol with Diphenhydramine?
MediHelp rates the interaction as moderate. Carisoprodol 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 strongly sedating antihistamine, and with carisoprodol it may cause marked drowsiness, impaired coordination and confusion, especially in older adults.
How serious is the interaction between Carisoprodol 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: Advise against driving and alcohol, and consider a non-sedating antihistamine. Monitor older patients for confusion and falls.
What other medicines interact with Carisoprodol?
MediHelp also lists interactions of Carisoprodol with, for example, Alfentanil, Alprazolam, Amobarbital. The full list is on the Carisoprodol page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
