Drug interactions
Flavoxate + Thioridazine
Severity: Moderate
Flavoxate 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
Thioridazine has marked anticholinergic activity that adds to flavoxate's effects, increasing the risk of urinary retention, constipation, blurred vision and confusion. Thioridazine's own QT prolongation risk is not changed by flavoxate.
What this interaction means in plain words
Flavoxate 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.
Flavoxate belongs to Genitourinary; Thioridazine belongs to Central Nervous System.
Why it happens
Additive anticholinergic pharmacodynamic effects.
What to do
Monitor for anticholinergic toxicity, especially in older adults, and consider an alternative to flavoxate if symptoms develop.
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 Flavoxate
- Clozapine + Flavoxate Major
- Abobotulinumtoxina + Flavoxate Moderate
- Aclidinium + Flavoxate Moderate
- Amantadine + Flavoxate Moderate
- Amitriptyline + Flavoxate Moderate
- Amoxapine + Flavoxate Moderate
Other interactions of Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
Frequently asked questions
Can I take Flavoxate with Thioridazine?
MediHelp rates the interaction as moderate. Flavoxate 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. Thioridazine has marked anticholinergic activity that adds to flavoxate's effects, increasing the risk of urinary retention, constipation, blurred vision and confusion. Thioridazine's own QT prolongation risk is not changed by flavoxate.
How serious is the interaction between Flavoxate 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 toxicity, especially in older adults, and consider an alternative to flavoxate if symptoms develop.
What other medicines interact with Flavoxate?
MediHelp also lists interactions of Flavoxate with, for example, Clozapine, Abobotulinumtoxina, Aclidinium. The full list is on the Flavoxate page.
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