Drug interactions
Cobicistat + Mifepristone
Severity: Major
Cobicistat and Mifepristone: 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
Cobicistat is a strong CYP3A4 inhibitor and can substantially raise mifepristone exposure when it is used for Cushing syndrome. This increases the risk of adverse effects such as hypokalemia, adrenal insufficiency and QT prolongation.
What this interaction means in plain words
Cobicistat and Mifepristone 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; Mifepristone belongs to Endocrine.
Why it happens
Inhibition of CYP3A4-mediated mifepristone metabolism by cobicistat.
What to do
Limit mifepristone to the reduced maximum dose in labeling for strong CYP3A4 inhibitors (300 mg initially, not above 600 mg). Monitor potassium, signs of adrenal insufficiency and ECG.
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 Mifepristone
- Apixaban + Mifepristone Contraindicated
- Argatroban + Mifepristone Contraindicated
- Cisapride + Mifepristone Contraindicated
- Cortisone + Mifepristone Contraindicated
- Cyclosporin + Mifepristone Contraindicated
- Dabigatran etexilate + Mifepristone 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 Mifepristone?
MediHelp rates the interaction as major. Cobicistat and Mifepristone 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 is a strong CYP3A4 inhibitor and can substantially raise mifepristone exposure when it is used for Cushing syndrome. This increases the risk of adverse effects such as hypokalemia, adrenal insufficiency and QT prolongation.
How serious is the interaction between Cobicistat and Mifepristone?
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 mifepristone to the reduced maximum dose in labeling for strong CYP3A4 inhibitors (300 mg initially, not above 600 mg). Monitor potassium, signs of adrenal insufficiency and ECG.
What other medicines interact with Mifepristone?
MediHelp also lists interactions of Mifepristone with, for example, Apixaban, Argatroban, Cisapride. The full list is on the Mifepristone page.
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