Drug interactions
Posaconazole + Solifenacin
Severity: Major
Posaconazole and Solifenacin: major interaction.
Last updated Sources: US FDA label
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
Posaconazole is a strong CYP3A4 inhibitor that raises solifenacin exposure, and both drugs can prolong the QT interval. This increases the risk of arrhythmia and antimuscarinic adverse effects.
What this interaction means in plain words
Posaconazole and Solifenacin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Posaconazole belongs to Anti Fungals; Solifenacin belongs to Genitourinary.
Why it happens
CYP3A4 inhibition raises solifenacin levels, with additive QT prolongation.
What to do
Limit solifenacin to 5 mg daily during strong CYP3A4 inhibition and obtain an ECG, correcting potassium and magnesium. Consider an alternative agent in patients with other QT risk factors.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Solifenacin
Other interactions of Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Frequently asked questions
Can I take Posaconazole with Solifenacin?
MediHelp rates the interaction as major. Posaconazole and Solifenacin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Posaconazole is a strong CYP3A4 inhibitor that raises solifenacin exposure, and both drugs can prolong the QT interval. This increases the risk of arrhythmia and antimuscarinic adverse effects.
How serious is the interaction between Posaconazole and Solifenacin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit solifenacin to 5 mg daily during strong CYP3A4 inhibition and obtain an ECG, correcting potassium and magnesium. Consider an alternative agent in patients with other QT risk factors.
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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