Drug interactions
Doxylamine + Thioridazine
Severity: Moderate
Doxylamine and Thioridazine: 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 is a strongly sedating, anticholinergic antihistamine often used for sleep. With thioridazine it can cause profound drowsiness, confusion, urinary retention and constipation, and it raises fall risk in older adults.
What this interaction means in plain words
Doxylamine and Thioridazine 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 belongs to Respiratory; Thioridazine belongs to Central Nervous System.
Why it happens
Additive H1 antagonism and muscarinic blockade producing CNS depression and anticholinergic toxicity.
What to do
Avoid regular use together and choose a non-anticholinergic sleep strategy. If combined, use the lowest dose and monitor for oversedation and anticholinergic effects.
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 Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
Other interactions of Doxylamine
Frequently asked questions
Can I take Doxylamine with Thioridazine?
MediHelp rates the interaction as moderate. Doxylamine and Thioridazine 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 is a strongly sedating, anticholinergic antihistamine often used for sleep. With thioridazine it can cause profound drowsiness, confusion, urinary retention and constipation, and it raises fall risk in older adults.
How serious is the interaction between Doxylamine and Thioridazine?
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 regular use together and choose a non-anticholinergic sleep strategy. If combined, use the lowest dose and monitor for oversedation and anticholinergic effects.
What other medicines interact with Thioridazine?
MediHelp also lists interactions of Thioridazine with, for example, Abiraterone, Adagrasib, Amiodarone. The full list is on the Thioridazine page.
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