Drug interactions
Cobicistat + Posaconazole
Severity: Major
Cobicistat and Posaconazole: 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
Both drugs are CYP3A4 substrates and inhibitors, so concurrent use may raise levels of either agent. The result may be more adverse effects from posaconazole or from drugs boosted by cobicistat, and the effect is hard to predict.
What this interaction means in plain words
Cobicistat and Posaconazole 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.
Cobicistat belongs to Miscellaneous; Posaconazole belongs to Anti Fungals.
Why it happens
Mutual CYP3A4 inhibition (cobicistat is also a P-gp inhibitor) reduces clearance of both drugs.
What to do
Avoid combining where an alternative exists. If used together, monitor posaconazole concentrations and QT interval, and watch for toxicity of other co-administered CYP3A substrates.
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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Other interactions of Cobicistat
- Alfuzosin + Cobicistat Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Cobicistat + Colchicine Contraindicated
- Cobicistat + Dronedarone Contraindicated
- Cobicistat + Eletriptan Contraindicated
- Cobicistat + Eplerenone Contraindicated
Frequently asked questions
Can I take Cobicistat with Posaconazole?
MediHelp rates the interaction as major. Cobicistat and Posaconazole 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. Both drugs are CYP3A4 substrates and inhibitors, so concurrent use may raise levels of either agent. The result may be more adverse effects from posaconazole or from drugs boosted by cobicistat, and the effect is hard to predict.
How serious is the interaction between Cobicistat and Posaconazole?
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 combining where an alternative exists. If used together, monitor posaconazole concentrations and QT interval, and watch for toxicity of other co-administered CYP3A substrates.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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