Drug interactions
Clemastine + Doxylamine
Severity: Moderate
Clemastine and Doxylamine: 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 are sedating first-generation antihistamines with anticholinergic activity. Combined use increases drowsiness, psychomotor impairment and anticholinergic adverse effects.
What this interaction means in plain words
Clemastine and Doxylamine 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; Doxylamine belongs to Respiratory.
Why it happens
Additive central H1-receptor blockade and muscarinic antagonism.
What to do
Avoid concurrent use and keep to one sedating antihistamine, including those found in over-the-counter sleep and cold products. Warn the patient against driving and monitor older patients for confusion.
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 Doxylamine
Frequently asked questions
Can I take Clemastine with Doxylamine?
MediHelp rates the interaction as moderate. Clemastine and Doxylamine 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 are sedating first-generation antihistamines with anticholinergic activity. Combined use increases drowsiness, psychomotor impairment and anticholinergic adverse effects.
How serious is the interaction between Clemastine and Doxylamine?
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 concurrent use and keep to one sedating antihistamine, including those found in over-the-counter sleep and cold products. Warn the patient against driving and monitor older patients for confusion.
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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