Atazanavir and Fosamprenavir interaction
Atazanavir and Fosamprenavir: 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
Others ↑ other protease inhibitor Coadministration with other protease inhibitors is not recommended.
Resistance to atazanavir may not preclude the subsequent use of other protease inhibitors [see Microbiology (12.4) ] .
Potential for REYATAZ to Affect Other Drugs Atazanavir is an inhibitor of CYP3A and UGT1A1.
From the Fosamprenavir (Fosamprenavir Calcium) label · effective 2026-06-30
HIV protease inhibitor: Atazanavir a Fosamprenavir calcium: Interaction has not been evaluated.
Fosamprenavir calcium/ritonavir: ↓ Atazanavir ↔ Amprenavir HIV protease inhibitors: Indinavir a , nelfinavir a Fosamprenavir calcium: ↑ Amprenavir Effect on indinavir and nelfinavir is not well established.
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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.