Atazanavir and Bosentan interaction
Atazanavir and Bosentan: 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 Bosentan (Tracleer) label · effective 2025-11-17
Co-administration of such combinations of a CYP2C9 inhibitor plus a strong or moderate CYP3A inhibitor with TRACLEER is not recommended.
Concomitant administration of both a CYP2C9 inhibitor (such as fluconazole or amiodarone) and a strong CYP3A inhibitor (e.g., ketoconazole, itraconazole) or a moderate CYP3A inhibitor (e.g., amprenavir, erythromycin, fluconazole, diltiazem) with TRACLEER will likely lead to large increases in plasma concentrations of bosentan.
From the Atazanavir (REYATAZ) label · effective 2024-12-05
Endothelin receptor antagonists: bosentan REYATAZ ↓ atazanavir REYATAZ with ritonavir ↑ bosentan Coadministration of bosentan and REYATAZ without ritonavir is not recommended.
• when coadministered with drugs that are strong inducers of CYP3A due to the potential for loss of therapeutic effect and development of resistance.
• Coadministration with drugs that are strong inducers of CYP3A, due to the potential for loss of therapeutic effect and development of resistance.
Initiation of medications that inhibit or induce CYP3A may increase or decrease concentrations of REYATAZ with ritonavir, respectively.
Potential for Other Drugs to Affect REYATAZ Atazanavir is a CYP3A4 substrate; therefore, drugs that induce CYP3A4 may decrease atazanavir plasma concentrations and reduce REYATAZ’s therapeutic effect ( see Table 16 ).
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.