Drug interactions
Isoniazid + Solifenacin
Severity: Minor
Isoniazid and Solifenacin: minor 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
Isoniazid is a variable CYP3A4 inhibitor and may modestly raise solifenacin exposure. This could increase antimuscarinic effects and, at high exposure, QT effects. The clinical impact is expected to be small in most patients.
What this interaction means in plain words
Isoniazid and Solifenacin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Isoniazid belongs to Anti Bacterial; Solifenacin belongs to Genitourinary.
Why it happens
Isoniazid inhibition of CYP3A4-mediated solifenacin metabolism, which is weak and variable.
What to do
No routine dose change is needed; watch for increased anticholinergic effects such as dry mouth, constipation and urinary retention.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Solifenacin
Other interactions of Isoniazid
Frequently asked questions
Can I take Isoniazid with Solifenacin?
MediHelp rates the interaction as minor. Isoniazid and Solifenacin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Isoniazid is a variable CYP3A4 inhibitor and may modestly raise solifenacin exposure. This could increase antimuscarinic effects and, at high exposure, QT effects. The clinical impact is expected to be small in most patients.
How serious is the interaction between Isoniazid and Solifenacin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose change is needed; watch for increased anticholinergic effects such as dry mouth, constipation 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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