Drug interactions
Darifenacin + Solifenacin
Severity: Moderate
Darifenacin 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
Using two antimuscarinic bladder agents together adds anticholinergic effects such as dry mouth, constipation, blurred vision, urinary retention and cognitive effects. There is no therapeutic advantage to combining them, and the burden of adverse effects rises.
What this interaction means in plain words
Darifenacin 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.
Darifenacin belongs to Genitourinary; Solifenacin belongs to Genitourinary.
Why it happens
Additive muscarinic receptor antagonism; darifenacin is also a CYP2D6 and moderate CYP3A4 substrate with weak CYP2D6 inhibition, so any kinetic effect on solifenacin is minor.
What to do
Avoid combining two antimuscarinics for overactive bladder; optimize the dose of a single agent or switch class (e.g., a beta-3 agonist). If used together, monitor for anticholinergic toxicity and urinary retention.
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 Darifenacin
Frequently asked questions
Can I take Darifenacin with Solifenacin?
MediHelp rates the interaction as moderate. Darifenacin 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. Using two antimuscarinic bladder agents together adds anticholinergic effects such as dry mouth, constipation, blurred vision, urinary retention and cognitive effects. There is no therapeutic advantage to combining them, and the burden of adverse effects rises.
How serious is the interaction between Darifenacin 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: Avoid combining two antimuscarinics for overactive bladder; optimize the dose of a single agent or switch class (e.g., a beta-3 agonist). If used together, monitor for anticholinergic toxicity and urinary retention.
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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