Atazanavir and Deflazacort interaction
Atazanavir and Deflazacort: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Atazanavir (REYATAZ) label · effective 2024-12-05
Coadministration of fluticasone propionate and REYATAZ with ritonavir is not recommended unless the potential benefit to the patient outweighs the risk of systemic corticosteroid side effects [see Warnings and Precautions (5.1) ] .
Corticosteroids: dexamethasone and other corticosteroids (all routes of administration) ↓ atazanavir ↑ corticosteroids Coadministration with dexamethasone or other corticosteroids that induce CYP3A may result in loss of therapeutic effect of REYATAZ and development of resistance to atazanavir and/or ritonavir.
Alternative corticosteroids should be considered.
Coadministration with corticosteroids (all routes of administration) that are metabolized by CYP3A, particularly for long-term use, may increase the risk for development of systemic corticosteroid effects including Cushing’s syndrome and adrenal suppression.
Consider the potential benefit of treatment versus the risk of systemic corticosteroid effects.
From the Deflazacort (EMFLAZA) label · effective 2025-11-13
Moderate or strong CYP3A4 inhibitors: Give one third of the recommended dosage of EMFLAZA ( 7.1 )
Co-administration of deflazacort with clarithromycin, a strong CYP3A4 inhibitor, increased total exposure to 21-desDFZ by about 3-fold.
Therefore, give one third the recommended dosage of EMFLAZA when moderate or strong CYP3A4 inhibitors (e.g., clarithromycin, fluconazole, diltiazem, verapamil, grapefruit juice) are used concomitantly with EMFLAZA [see Dosage and Administration ( 2.5 ) and Clinical Pharmacology ( 12.3 )] .
CYP3A4 Inhibitors and Inducers Moderate or Strong CYP3A4 Inhibitors The active metabolite of deflazacort, 21-desDFZ, is a substrate of CYP3A4 [see Clinical Pharmacology ( 12.3 )] .
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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.