Drug interactions
Clemastine + Diazepam intranasal
Severity: Moderate
Clemastine and Diazepam intranasal: 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
Diazepam is a benzodiazepine, and a sedating antihistamine can increase drowsiness, impair coordination and add to respiratory depression. This matters because intranasal diazepam is used for seizure emergencies in which sedation is already expected.
What this interaction means in plain words
Clemastine and Diazepam intranasal 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 CNS depression from benzodiazepine GABA-A potentiation and central H1 receptor blockade.
What to do
Monitor sedation and breathing after dosing, and consider a non-sedating antihistamine for ongoing use. Advise avoiding alcohol and driving.
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 Clemastine and Diazepam intranasal, 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 Clemastine
Frequently asked questions
Can I take Clemastine with Diazepam intranasal?
MediHelp rates the interaction as moderate. Clemastine and Diazepam intranasal 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. Diazepam is a benzodiazepine, and a sedating antihistamine can increase drowsiness, impair coordination and add to respiratory depression. This matters because intranasal diazepam is used for seizure emergencies in which sedation is already expected.
How serious is the interaction between Clemastine and Diazepam intranasal?
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 sedation and breathing after dosing, and consider a non-sedating antihistamine for ongoing use. Advise avoiding alcohol and driving.
What other medicines interact with Clemastine?
MediHelp also lists interactions of Clemastine with, for example, Alfentanil, Benzhydrocodone / acetaminophen, Buprenorphine buccal. The full list is on the Clemastine 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.
