Atazanavir and Posaconazole interaction
Atazanavir and Posaconazole: 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 Posaconazole (NOXAFIL) label · effective 2026-02-13
Anti-HIV Drugs that are CYP3A4 Substrates Mechanism and Clinical Effect(s) Ritonavir and atazanavir are CYP3A4 substrates and posaconazole increased plasma concentrations of these drugs [see Clinical Pharmacology (12.3) ].
Prevention or Management Ritonavir and Atazanavir Monitor frequently for adverse reactions and toxicity of ritonavir and atazanavir during concomitant use.
Effects of Noxafil and Noxafil PowderMix on Other Drugs Posaconazole is a strong CYP3A4 inhibitor.
From the Atazanavir (REYATAZ) label · effective 2024-12-05
Direct-Acting Oral Anticoagulants: betrixaban, dabigatran, edoxaban ↑ betrixaban ↑ dabigatran ↑ edoxaban Concomitant use of REYATAZ with ritonavir, a strong CYP3A4/P-gp inhibitor, may result in an increased risk of bleeding.
Refer to the respective DOAC prescribing information regarding dosing instructions for coadministration with P-gp inhibitors. rivaroxaban REYATAZ with ritonavir ↑ rivaroxaban Coadministration of REYATAZ with ritonavir, a strong CYP3A4/P-gp inhibitor, and rivaroxaban is not recommended, as it may result in an increased risk of bleeding.
Close monitoring is recommended when REYATAZ is coadministered with rivaroxaban. apixaban REYATAZ with ritonavir ↑ apixaban Concomitant use of REYATAZ with ritonavir, a strong CYP3A4/P-gp inhibitor, may result in an increased risk of bleeding.
Antifungals: ketoconazole, itraconazole REYATAZ with ritonavir: ↑ ketoconazole ↑ itraconazole Coadministration of ketoconazole has only been studied with REYATAZ without ritonavir (negligible increase in atazanavir AUC and C max ).
Potential for REYATAZ to Affect Other Drugs Atazanavir is an inhibitor of CYP3A and UGT1A1.
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.