Drug interactions
Clemastine + Hydroxyzine
Severity: Moderate
Clemastine and Hydroxyzine: 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 are sedating H1 antihistamines with anticholinergic properties. Combined use increases drowsiness, impaired alertness and anticholinergic effects, and hydroxyzine also carries a QT prolongation risk.
What this interaction means in plain words
Clemastine and Hydroxyzine 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.
Clemastine belongs to Respiratory; Hydroxyzine belongs to Respiratory.
Why it happens
Additive central H1-receptor antagonism and muscarinic blockade.
What to do
Avoid combining the two and use one agent at the lowest effective dose. Counsel the patient about impaired driving and monitor older patients for confusion and urinary retention.
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 Clemastine
Other interactions of Hydroxyzine
- Droperidol + Hydroxyzine Contraindicated
- Hydroxyzine + Pimozide Contraindicated
- Hydroxyzine + Thioridazine Contraindicated
- Hydroxyzine + Vandetanib Contraindicated
- Alfentanil + Hydroxyzine Major
- Amiodarone + Hydroxyzine Major
Frequently asked questions
Can I take Clemastine with Hydroxyzine?
MediHelp rates the interaction as moderate. Clemastine and Hydroxyzine 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 are sedating H1 antihistamines with anticholinergic properties. Combined use increases drowsiness, impaired alertness and anticholinergic effects, and hydroxyzine also carries a QT prolongation risk.
How serious is the interaction between Clemastine and Hydroxyzine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining the two and use one agent at the lowest effective dose. Counsel the patient about impaired driving and monitor older patients for confusion and urinary retention.
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.
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