Drug interactions
OnabotulinumtoxinA + Solifenacin
Severity: Moderate
OnabotulinumtoxinA 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
Anticholinergic drugs may add to the effects of botulinum toxin, and systemic antimuscarinic effects can be heightened. In bladder use, the combination may increase the risk of incomplete emptying and urinary retention, and rarely excessive muscle weakness.
What this interaction means in plain words
OnabotulinumtoxinA 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.
OnabotulinumtoxinA belongs to Musculoskeletal; Solifenacin belongs to Genitourinary.
Why it happens
Additive inhibition of cholinergic transmission, presynaptic by the toxin and receptor-level by solifenacin.
What to do
Monitor post-void residual volume and urinary retention after bladder injection, and watch for generalized weakness or swallowing difficulty. Review the need for continued solifenacin after injection.
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 OnabotulinumtoxinA
Frequently asked questions
Can I take OnabotulinumtoxinA with Solifenacin?
MediHelp rates the interaction as moderate. OnabotulinumtoxinA 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. Anticholinergic drugs may add to the effects of botulinum toxin, and systemic antimuscarinic effects can be heightened. In bladder use, the combination may increase the risk of incomplete emptying and urinary retention, and rarely excessive muscle weakness.
How serious is the interaction between OnabotulinumtoxinA 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 post-void residual volume and urinary retention after bladder injection, and watch for generalized weakness or swallowing difficulty. Review the need for continued solifenacin after injection.
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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