Emtricitabine and tenofovir and Nirmatrelvir and ritonavir interaction
Emtricitabine and tenofovir and Nirmatrelvir and ritonavir: 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 Emtricitabine and tenofovir (DESCOVY) label · effective 2026-07-07
Drug Interactions Concomitant Drug Class: Drug Name Effect on Concentration ↓=Decrease Clinical Comment ↑= Increase Antiretroviral Agents: Protease Inhibitors (PI) tipranavir/ritonavir ↓ TAF Coadministration with DESCOVY is not recommended. atazanavir/cobicistat ↑ TAF Coadministration with DESCOVY in pediatric patients weighing 14 to < 35 kg is not recommended…
Coadministration of DESCOVY with other drugs that inhibit P-gp and BCRP may increase the absorption and plasma concentration of TAF.
TAF is a weak inhibitor of CYP3A in vitro .
…of DESCOVY, no clinically significant drug interactions have been either observed or are expected when DESCOVY is combined with the following antiretroviral agents: atazanavir with ritonavir, atazanavir with cobicistat (in those weighing ≥35 kg), darunavir with ritonavir or cobicistat, dolutegravir, efavirenz, ledipasvir, lopinavir/ritonavir, maraviroc, nevirapine,…
From the Nirmatrelvir and ritonavir (Paxlovid) label · effective 2026-02-19
Anti-HIV efavirenz, maraviroc, nevirapine, zidovudine, bictegravir/ emtricitabine/ tenofovir ↑ efavirenz ↑ maraviroc ↑ nevirapine ↓ zidovudine ↑ bictegravir ↔ emtricitabine ↑ tenofovir For further information, refer to the respective anti-HIV drugs prescribing information.
Anti-HIV protease inhibitors atazanavir, darunavir, tipranavir ↑ protease inhibitor For further information, refer to the respective protease inhibitors' prescribing information.
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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.