Budesonide and formoterol and Nirmatrelvir and ritonavir interaction
Budesonide and formoterol and Nirmatrelvir and ritonavir: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Budesonide and formoterol (Budesonide and Formoterol Fumarate Dihydrate) label · effective 2026-04-24
Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir): Risk of increased systemic corticosteroid effects.
Drug Interactions With Strong Cytochrome P450 3A4 Inhibitors Caution should be exercised when considering the coadministration of budesonide and formoterol fumarate dihydrate with ketoconazole, and other known strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin) because…
Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir): Use with caution.
After oral administration of ketoconazole, a strong inhibitor of CYP3A4, the mean plasma concentration of orally administered budesonide increased.
Caution should be exercised when considering the coadministration of budesonide and formoterol fumarate dihydrate with long-term ketoconazole and other known strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin) [see Warnings and Precautions (5.9) ] .
From the Nirmatrelvir and ritonavir (Paxlovid) label · effective 2026-02-19
Corticosteroids primarily metabolized by CYP3A betamethasone, budesonide, ciclesonide, dexamethasone, fluticasone, methylprednisolone, mometasone, triamcinolone ↑ corticosteroid Co-administration with corticosteroids (all routes of administration) of which exposures are significantly increased by strong CYP3A inhibitors can increase the risk for Cushing’s syndrome…
Alternative corticosteroids including beclomethasone, prednisone, and prednisolone should be considered.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.