Drug interactions
Dexamethasone + Nirmatrelvir / ritonavir
Severity: Moderate
Dexamethasone and Nirmatrelvir / ritonavir: moderate 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
Ritonavir-boosted nirmatrelvir potently inhibits CYP3A4 and can increase dexamethasone exposure. Short-term use is often acceptable, but prolonged co-administration raises the risk of Cushing syndrome and adrenal suppression. Dexamethasone may also reduce nirmatrelvir exposure through CYP3A4 induction.
What this interaction means in plain words
Dexamethasone and Nirmatrelvir / ritonavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Ritonavir inhibits CYP3A4 and P-glycoprotein, decreasing dexamethasone clearance, while dexamethasone may induce CYP3A4.
What to do
Monitor for corticosteroid excess, especially hyperglycemia, and limit the duration of co-administration. Consider prednisolone or another alternative for prolonged therapy.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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
Frequently asked questions
Can I take Dexamethasone with Nirmatrelvir / ritonavir?
MediHelp rates the interaction as moderate. Dexamethasone and Nirmatrelvir / ritonavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Ritonavir-boosted nirmatrelvir potently inhibits CYP3A4 and can increase dexamethasone exposure. Short-term use is often acceptable, but prolonged co-administration raises the risk of Cushing syndrome and adrenal suppression. Dexamethasone may also reduce nirmatrelvir exposure through CYP3A4 induction.
How serious is the interaction between Dexamethasone and Nirmatrelvir / ritonavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for corticosteroid excess, especially hyperglycemia, and limit the duration of co-administration. Consider prednisolone or another alternative for prolonged therapy.
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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