Doravirine and Rifabutin interaction
Doravirine 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
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 ).
ND ↓ 50% in AUC, ↓ 68% in C 24 ↔ in C max If concomitant use is necessary, increase the doravirine dosage as instructed in doravirine-containing product prescribing information.
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…
Antiretroviral and Anti-HCV Drug Interactions Protease inhibitors act as substrates or inhibitors of CYP3A4 mediated metabolism.
From the Doravirine (PIFELTRO) label · effective 2026-07-08
PIFELTRO is contraindicated when co-administered with drugs that are strong cytochrome P450 (CYP)3A enzyme inducers as significant decreases in doravirine plasma concentrations may occur, which may decrease the effectiveness of PIFELTRO [see Warnings and Precautions (5.2) , Drug Interactions (7.1) , and Clinical Pharmacology (12.3) ] .
John's wort ( Hypericum perforatum) PIFELTRO is contraindicated when co-administered with drugs that are strong cytochrome P450 (CYP)3A enzyme inducers as significant decreases in doravirine plasma concentrations may occur, which may decrease the effectiveness of PIFELTRO.
At least a 4-week cessation period is recommended prior to initiation of PIFELTRO. rifabutin ↓ doravirine Increase PIFELTRO dosage to one tablet twice daily when co-administered with rifabutin [see Dosage and Administration (2.2) ] .
Effect of Other Drugs on PIFELTRO Co-administration of PIFELTRO with a CYP3A inducer decreases doravirine plasma concentrations, which may reduce PIFELTRO efficacy [see Contraindications (4) , Warnings and Precautions (5.2) , and Clinical Pharmacology (12.3) ] .
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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.