Drug interactions
Dexamethasone-neomycin-polymyxin + Nirmatrelvir / ritonavir
Severity: Moderate
Dexamethasone-neomycin-polymyxin 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 is a potent CYP3A4 inhibitor and can markedly raise systemic dexamethasone levels. Prolonged coadministration may cause Cushing syndrome and adrenal suppression. Brief topical use gives little systemic exposure.
What this interaction means in plain words
Dexamethasone-neomycin-polymyxin 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 strongly inhibits CYP3A4, decreasing dexamethasone clearance.
What to do
With systemic dexamethasone, consider an alternative steroid such as prednisolone or beclomethasone, or use the lowest dose for the shortest time. Topical use for a short course needs no adjustment.
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-neomycin-polymyxin
- Dexamethasone-neomycin-polymyxin + Ketorolac Major
- Dexamethasone-neomycin-polymyxin + Lapatinib Major
- Dexamethasone-neomycin-polymyxin + Levofloxacin Major
- Dexamethasone-neomycin-polymyxin + Mifepristone Major
- Dexamethasone-neomycin-polymyxin + Moxifloxacin Major
- Aldesleukin + Dexamethasone-neomycin-polymyxin Moderate
Frequently asked questions
Can I take Dexamethasone-neomycin-polymyxin with Nirmatrelvir / ritonavir?
MediHelp rates the interaction as moderate. Dexamethasone-neomycin-polymyxin 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 is a potent CYP3A4 inhibitor and can markedly raise systemic dexamethasone levels. Prolonged coadministration may cause Cushing syndrome and adrenal suppression. Brief topical use gives little systemic exposure.
How serious is the interaction between Dexamethasone-neomycin-polymyxin 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: With systemic dexamethasone, consider an alternative steroid such as prednisolone or beclomethasone, or use the lowest dose for the shortest time. Topical use for a short course needs no adjustment.
What other medicines interact with Dexamethasone-neomycin-polymyxin?
MediHelp also lists interactions of Dexamethasone-neomycin-polymyxin with, for example, Ketorolac, Lapatinib, Levofloxacin. The full list is on the Dexamethasone-neomycin-polymyxin page.
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