Drug interactions
Doxepin + Solifenacin
Severity: Moderate
Doxepin and Solifenacin: 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 with strong anticholinergic effects and some QT-prolonging potential, which add to those of solifenacin. This raises the risk of confusion, constipation, urinary retention, tachycardia and arrhythmia, particularly in older adults.
What this interaction means in plain words
Doxepin and Solifenacin 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; Solifenacin belongs to Genitourinary.
Why it happens
Additive antimuscarinic activity and additive QT interval prolongation.
What to do
Monitor for anticholinergic toxicity and cognitive effects, and obtain an ECG in patients with cardiac risk factors; use the lowest effective doses.
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 Solifenacin
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 Solifenacin?
MediHelp rates the interaction as moderate. Doxepin and Solifenacin 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 with strong anticholinergic effects and some QT-prolonging potential, which add to those of solifenacin. This raises the risk of confusion, constipation, urinary retention, tachycardia and arrhythmia, particularly in older adults.
How serious is the interaction between Doxepin and Solifenacin?
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 and cognitive effects, and obtain an ECG in patients with cardiac risk factors; use the lowest effective doses.
What other medicines interact with Solifenacin?
MediHelp also lists interactions of Solifenacin with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Solifenacin page.
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