Drug interactions
Flavoxate + Tolterodine
Severity: Moderate
Flavoxate and Tolterodine: 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
Flavoxate has antimuscarinic and smooth muscle relaxant properties, so combining it with tolterodine adds to anticholinergic effects. Patients may have more dry mouth, blurred vision, constipation, confusion and urinary retention.
What this interaction means in plain words
Flavoxate and Tolterodine 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; Tolterodine belongs to Genitourinary.
Why it happens
Additive antimuscarinic effects.
What to do
Avoid routine co-prescription, and monitor for anticholinergic effects and residual urine if both are used. Reduce or stop one agent 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 Tolterodine
Other interactions of Flavoxate
- Clozapine + Flavoxate Major
- Abobotulinumtoxina + Flavoxate Moderate
- Aclidinium + Flavoxate Moderate
- Amantadine + Flavoxate Moderate
- Amitriptyline + Flavoxate Moderate
- Amoxapine + Flavoxate Moderate
Frequently asked questions
Can I take Flavoxate with Tolterodine?
MediHelp rates the interaction as moderate. Flavoxate and Tolterodine 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 has antimuscarinic and smooth muscle relaxant properties, so combining it with tolterodine adds to anticholinergic effects. Patients may have more dry mouth, blurred vision, constipation, confusion and urinary retention.
How serious is the interaction between Flavoxate and Tolterodine?
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 routine co-prescription, and monitor for anticholinergic effects and residual urine if both are used. Reduce or stop one agent if symptoms develop.
What other medicines interact with Tolterodine?
MediHelp also lists interactions of Tolterodine with, for example, Clarithromycin, Clozapine, Cobicistat. The full list is on the Tolterodine page.
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