Drug interactions
Clemastine + Trifluoperazine
Severity: Moderate
Clemastine and Trifluoperazine: 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 drugs depress the central nervous system, so taking them together can produce deeper drowsiness and slower psychomotor performance. Trifluoperazine and clemastine also have anticholinergic activity that may add to dry mouth, constipation and confusion, particularly in older adults.
What this interaction means in plain words
Clemastine and Trifluoperazine 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 through histamine H1 blockade and dopamine antagonism, plus additive anticholinergic effects.
What to do
Warn the patient about impaired alertness and driving, and start with lower doses in elderly patients. Reassess the need for the antihistamine if sedation or anticholinergic effects become troublesome.
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 Trifluoperazine, 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 Trifluoperazine?
MediHelp rates the interaction as moderate. Clemastine and Trifluoperazine 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 drugs depress the central nervous system, so taking them together can produce deeper drowsiness and slower psychomotor performance. Trifluoperazine and clemastine also have anticholinergic activity that may add to dry mouth, constipation and confusion, particularly in older adults.
How serious is the interaction between Clemastine and Trifluoperazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Warn the patient about impaired alertness and driving, and start with lower doses in elderly patients. Reassess the need for the antihistamine if sedation or anticholinergic effects become troublesome.
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.
