Atazanavir and Rifabutin interaction
Atazanavir and Rifabutin: 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
Antimycobacterials: rifampin ↓ atazanavir Coadministration of REYATAZ with rifampin is contraindicated due to the risk for loss of virologic response and development of resistance [see Contraindications (4) ] . rifabutin ↑ rifabutin A rifabutin dose reduction of up to 75% (eg, 150 mg every other day or 3 times per week) is 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.
Increased monitoring for rifabutin-associated adverse reactions including neutropenia is warranted.
Initiation of medications that inhibit or induce CYP3A may increase or decrease concentrations of REYATAZ with ritonavir, respectively.
From the Rifabutin label · effective 2026-09-01
Therefore, co-administration with antiretroviral and anti-HCV drugs metabolized by CYP3A is not recommended or there may be a need to increase the dose of antiretroviral or anti-HCV drugs (see PRECAUTIONS-Drug Interactions ).
The concomitant use of protease inhibitors may require at least a 50% reduction in rifabutin dose, and depending on the protease inhibitor, an adjustment of the antiretroviral drug dose.
Co-administration with antiretroviral drugs metabolized by CYP3A, including but not limited to products containing bictegravir, elvitegravir, oral rilpivirine, or doravirine and anti-HCV drugs including but not limited to sofosbuvir (alone or in combination) may decrease plasma concentrations of those drugs, which may lead to loss of virologic response and possible…
Effect of Other Drugs on Rifabutin Pharmacokinetics Some drugs that inhibit CYP3A may significantly increase the plasma concentration of rifabutin.
Therefore, carefully monitor for rifabutin associated adverse events in those patients also receiving CYP3A inhibitors, which include fluconazole and clarithromycin.
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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.