Drug interactions
Doxylamine + Trifluoperazine
Severity: Moderate
Doxylamine 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
Doxylamine and trifluoperazine both have sedative and anticholinergic properties. Combined use may increase drowsiness, cognitive impairment and anticholinergic effects such as dry mouth, constipation and urinary retention.
What this interaction means in plain words
Doxylamine 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 and antimuscarinic activity from H1, muscarinic and dopamine receptor blockade.
What to do
Monitor for sedation and anticholinergic toxicity, and avoid routine use of doxylamine for sleep in patients on trifluoperazine. Take particular care in elderly patients.
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 Doxylamine
Frequently asked questions
Can I take Doxylamine with Trifluoperazine?
MediHelp rates the interaction as moderate. Doxylamine 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. Doxylamine and trifluoperazine both have sedative and anticholinergic properties. Combined use may increase drowsiness, cognitive impairment and anticholinergic effects such as dry mouth, constipation and urinary retention.
How serious is the interaction between Doxylamine 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: Monitor for sedation and anticholinergic toxicity, and avoid routine use of doxylamine for sleep in patients on trifluoperazine. Take particular care in elderly patients.
What other medicines interact with Doxylamine?
MediHelp also lists interactions of Doxylamine with, for example, Belladonna and opium, Benzhydrocodone / acetaminophen, Brexanolone. The full list is on the Doxylamine page.
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