Drug interactions
Cobimetinib + Dexamethasone
Severity: Major
Cobimetinib and Dexamethasone: major 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
Cobimetinib is a CYP3A substrate, and dexamethasone as a CYP3A inducer may substantially reduce its exposure. This could compromise antitumor efficacy.
What this interaction means in plain words
Cobimetinib and Dexamethasone 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.
Cobimetinib belongs to Oncology; Dexamethasone belongs to Endocrine.
Why it happens
Dexamethasone induces CYP3A, increasing cobimetinib clearance.
What to do
Avoid long-term dexamethasone with cobimetinib; use an alternative anti-emetic or anti-inflammatory strategy. If a short course is essential, monitor for loss of response.
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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Other interactions of Dexamethasone
- Bcg vaccine live + Dexamethasone Contraindicated
- Dexamethasone + Mifepristone Contraindicated
- Dexamethasone + Rilpivirine Contraindicated
- Dexamethasone + Smallpox vaccine live Contraindicated
- Dexamethasone + Varicella virus vaccine live Contraindicated
- Dexamethasone + Yellow fever vaccine Contraindicated
Other interactions of Cobimetinib
- Cobimetinib + Efavirenz Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Amobarbital + Cobimetinib Major
- Apalutamide + Cobimetinib Major
- Aprepitant + Cobimetinib Major
- Bosentan + Cobimetinib Major
Frequently asked questions
Can I take Cobimetinib with Dexamethasone?
MediHelp rates the interaction as major. Cobimetinib and Dexamethasone 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. Cobimetinib is a CYP3A substrate, and dexamethasone as a CYP3A inducer may substantially reduce its exposure. This could compromise antitumor efficacy.
How serious is the interaction between Cobimetinib and Dexamethasone?
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 long-term dexamethasone with cobimetinib; use an alternative anti-emetic or anti-inflammatory strategy. If a short course is essential, monitor for loss of response.
What other medicines interact with Dexamethasone?
MediHelp also lists interactions of Dexamethasone with, for example, Bcg vaccine live, Mifepristone, Rilpivirine. The full list is on the Dexamethasone page.
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