Lenacapavir and Ritonavir interaction
Lenacapavir 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 Lenacapavir (Sunlenca) label · effective 2026-08-27
Antiretroviral Agents: atazanavir/cobicistat Drug-drug interaction study was conducted. atazanavir/ritonavir ↑ lenacapavir (atazanavir/cobicistat, atazanavir/ritonavir) Concomitant administration of efavirenz, nevirapine, or tipranavir/ritonavir may result in loss of therapeutic effect and development of resistance. efavirenz nevirapine tipranavir/ritonavir ↓…
Concomitant administration of SUNLENCA with strong CYP3A inducers is contraindicated due to decreased lenacapavir plasma concentrations, which may result in the loss of therapeutic effect and development of resistance to SUNLENCA [see Drug Interactions (7.1) ] .
Concomitant administration of SUNLENCA is contraindicated with strong CYP3A inducers.
Concomitant administration of SUNLENCA with strong CYP3A inducers during SUNLENCA treatment is contraindicated [see Contraindications (4) ] .
Concomitant administration of SUNLENCA with moderate CYP3A inducers during SUNLENCA treatment is not recommended.
From the Ritonavir (Norvir) label · effective 2026-07-23
Hepatotoxicity Hepatic transaminase elevations exceeding 5 times the upper limit of normal, clinical hepatitis, and jaundice have occurred in patients receiving NORVIR alone or in combination with other antiretroviral drugs (see Table 2).
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.