Drug interactions
Doxepin + Flavoxate
Severity: Moderate
Doxepin and Flavoxate: 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
Doxepin is a tricyclic antidepressant with significant anticholinergic effects, which flavoxate can add to. This raises the risk of urinary retention, constipation, dry mouth, tachycardia and confusion.
What this interaction means in plain words
Doxepin and Flavoxate 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.
Doxepin belongs to Dermatology; Flavoxate belongs to Genitourinary.
Why it happens
Additive muscarinic receptor antagonism.
What to do
Monitor for urinary retention, constipation and confusion, especially in older adults. Reduce the dose or choose a less anticholinergic alternative if needed.
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 Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Doxepin with Flavoxate?
MediHelp rates the interaction as moderate. Doxepin and Flavoxate 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. Doxepin is a tricyclic antidepressant with significant anticholinergic effects, which flavoxate can add to. This raises the risk of urinary retention, constipation, dry mouth, tachycardia and confusion.
How serious is the interaction between Doxepin and Flavoxate?
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 urinary retention, constipation and confusion, especially in older adults. Reduce the dose or choose a less anticholinergic alternative if needed.
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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