Drug interactions
Bosentan + Fluconazole
Severity: Major
Bosentan and Fluconazole: 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
Fluconazole inhibits both CYP2C9 and CYP3A4, the main enzymes metabolizing bosentan, and can substantially raise bosentan levels. This increases the risk of hepatotoxicity, hypotension and fluid retention.
What this interaction means in plain words
Bosentan and Fluconazole 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.
Bosentan belongs to Miscellaneous; Fluconazole belongs to Anti Fungals.
Why it happens
Dual inhibition of CYP2C9 and CYP3A4 reduces bosentan clearance.
What to do
Avoid the combination where possible, as concomitant inhibitors of both enzymes are not recommended. If used, monitor liver enzymes closely and watch for hypotension and edema.
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 Fluconazole
- Dihydroergotamine intranasal + Fluconazole Contraindicated
- Dihydroergotamine + Fluconazole Contraindicated
- Dofetilide + Fluconazole Contraindicated
- Domperidone + Fluconazole Contraindicated
- Dronedarone + Fluconazole Contraindicated
- Erythromycin + Fluconazole Contraindicated
Other interactions of Bosentan
- Bosentan + Cyclosporin Contraindicated
- Bosentan + Glibenclamide Contraindicated
- Bosentan + Glyburide-metformin Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Bosentan + Sparsentan Contraindicated
- Artemether / lumefantrine + Bosentan Major
Frequently asked questions
Can I take Bosentan with Fluconazole?
MediHelp rates the interaction as major. Bosentan and Fluconazole 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. Fluconazole inhibits both CYP2C9 and CYP3A4, the main enzymes metabolizing bosentan, and can substantially raise bosentan levels. This increases the risk of hepatotoxicity, hypotension and fluid retention.
How serious is the interaction between Bosentan and Fluconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible, as concomitant inhibitors of both enzymes are not recommended. If used, monitor liver enzymes closely and watch for hypotension and edema.
What other medicines interact with Fluconazole?
MediHelp also lists interactions of Fluconazole with, for example, Dihydroergotamine intranasal, Dihydroergotamine, Dofetilide. The full list is on the Fluconazole page.
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