Drug interactions
Dimenhydrinate + Doxepin
Severity: Moderate
Dimenhydrinate and Doxepin: 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
Doxepin is a sedating tricyclic antidepressant with strong antihistaminic and anticholinergic activity. Together with dimenhydrinate it increases drowsiness and anticholinergic effects such as dry mouth, urinary retention, constipation and confusion, particularly in older patients.
What this interaction means in plain words
Dimenhydrinate and Doxepin 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.
Dimenhydrinate belongs to Respiratory; Doxepin belongs to Dermatology.
Why it happens
Additive central H1 antagonism and muscarinic receptor blockade.
What to do
Monitor for oversedation and anticholinergic toxicity, and avoid the combination in older adults. Consider a non-sedating alternative to the antihistamine.
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 Dimenhydrinate
Other interactions of Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Dimenhydrinate with Doxepin?
MediHelp rates the interaction as moderate. Dimenhydrinate and Doxepin 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. Doxepin is a sedating tricyclic antidepressant with strong antihistaminic and anticholinergic activity. Together with dimenhydrinate it increases drowsiness and anticholinergic effects such as dry mouth, urinary retention, constipation and confusion, particularly in older patients.
How serious is the interaction between Dimenhydrinate and Doxepin?
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 for oversedation and anticholinergic toxicity, and avoid the combination in older adults. Consider a non-sedating alternative to the antihistamine.
What other medicines interact with Dimenhydrinate?
MediHelp also lists interactions of Dimenhydrinate with, for example, Belladonna and opium, Brexanolone, Calcium / magnesium / potassium / sodium oxybates. The full list is on the Dimenhydrinate page.
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