Drug interactions
Homatropine + Thioridazine
Severity: Moderate
Homatropine 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
Homatropine is an antimuscarinic that adds to the strong anticholinergic activity of thioridazine. The combination can produce dry mouth, constipation, urinary retention, blurred vision and confusion, especially in older patients.
What this interaction means in plain words
Homatropine 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.
Homatropine belongs to Genitourinary; Thioridazine belongs to Central Nervous System.
Why it happens
Additive antimuscarinic effects through pharmacodynamic synergism.
What to do
Monitor for anticholinergic effects and reduce the dose or stop one agent if they occur; use extra care in older adults and those with glaucoma or urinary obstruction.
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 Homatropine
- Amantadine + Homatropine Moderate
- Amitriptyline + Homatropine Moderate
- Atropine + Homatropine Moderate
- Benztropine + Homatropine Moderate
- Bethanechol + Homatropine Moderate
- Chlorpromazine + Homatropine Moderate
Frequently asked questions
Can I take Homatropine with Thioridazine?
MediHelp rates the interaction as moderate. Homatropine 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. Homatropine is an antimuscarinic that adds to the strong anticholinergic activity of thioridazine. The combination can produce dry mouth, constipation, urinary retention, blurred vision and confusion, especially in older patients.
How serious is the interaction between Homatropine 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: Monitor for anticholinergic effects and reduce the dose or stop one agent if they occur; use extra care in older adults and those with glaucoma or urinary obstruction.
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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