Elvitegravir, cobicistat, emtricitabine, and tenofovir and Rifabutin interaction
Elvitegravir, cobicistat, emtricitabine, and tenofovir 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 Rifabutin label · effective 2026-09-01
Bictegravir 75 mg once a day 300 mg once a day (fasted) Healthy subjects ND ↓ AUC 38% ↓ C min 56% ↓ C max 20% Co-administration of rifabutin with Biktarvy (bictegravir/emtricitabine/ tenofovir alafenamide) is not recommended due to an expected decrease in tenofovir alafenamide in addition to the reported reduction in bictegravir.
Co-administration of rifabutin with elvitegravir/ cobicistat is not recommended due to an expected decrease in elvitegravir exposure.
ND ↓ AUC by 42% ↓ C min by 48% ↓ C max by 31% Co-administration of rifabutin with Odefsey (rilpivirine/tenofovir alafenamide/emtricitabine) is not recommended, due to an expected decrease in tenofovir alafenamide in addition to the reported reduction in rilpivirine.
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.
From the Elvitegravir, cobicistat, emtricitabine, and tenofovir (Genvoya) label · effective 2025-02-03
Antimycobacterial: rifampin ↓ elvitegravir ↓ cobicistat ↓ TAF Coadministration with rifampin is contraindicated due to potential for loss of therapeutic effect and development of resistance. rifabutin rifapentine Coadministration of GENVOYA with rifabutin or rifapentine is not recommended.
Strongly induce CYP3A, which may lead to lower exposure of one or more components and loss of efficacy of GENVOYA and possible resistance.
Drugs that induce CYP3A activity are expected to increase the clearance of elvitegravir and cobicistat, resulting in decreased plasma concentration of cobicistat, elvitegravir, and TAF, which may lead to loss of therapeutic effect of GENVOYA and development of resistance (see Table 5 ).
Corticosteroids: e.g., betamethasone budesonide ciclesonide dexamethasone fluticasone methylprednisolone mometasone prednisone triamcinolone ↓ elvitegravir ↓ cobicistat ↑ corticosteroids Coadministration with oral dexamethasone or other systemic corticosteroids that induce CYP3A may result in loss of therapeutic effect and development of resistance to elvitegravir.
Drugs that induce CYP3A can alter the concentrations of one or more components of GENVOYA.
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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.