Darunavir and cobicistat and Rifabutin interaction
Darunavir and cobicistat 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
Co-administration of rifabutin with elvitegravir/ cobicistat is not recommended due to an expected decrease in elvitegravir exposure.
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.
From the Darunavir and cobicistat (PREZCOBIX) label · effective 2026-02-01
Antimycobacterials: rifampin ↓ darunavir ↓ cobicistat Co-administration is contraindicated due to potential for loss of therapeutic effect and development of resistance. rifabutin ↑ rifabutin cobicistat: effects unknown darunavir: effects unknown When used in combination with PREZCOBIX or PREZCOBIX PED, the recommended dose of rifabutin is 150 mg every other…
Monitor for rifabutin-associated adverse reactions including neutropenia and uveitis. rifapentine ↓ darunavir Co-administration with rifapentine is not recommended.
Co-administration of PREZCOBIX or PREZCOBIX PED with CYP3A inducers may lead to lower exposures of darunavir and cobicistat and potential loss of efficacy of darunavir and possible resistance.
Anticonvulsants with CYP3A induction effects that are NOT contraindicated: e.g. eslicarbazepine, oxcarbazepine ↓ cobicistat darunavir: effect unknown Consider alternative anticonvulsant or antiretroviral therapy to avoid potential changes in exposures.
Initiation of medications that inhibit or induce CYP3A may respectively increase or decrease concentrations of PREZCOBIX or PREZCOBIX PED.
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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.