Efavirenz and Ritlecitinib interaction
Efavirenz and Ritlecitinib: 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 Ritlecitinib (Litfulo) label · effective 2026-06-17
• Certain CYP3A inducers: Coadministration with strong inducers of CYP3A is not recommended.
Intervention Coadministration with strong inducers of CYP3A is not recommended.
Clinically Significant Interactions Affecting LITFULO CYP3A Inducers Clinical Impact Concomitant use of strong CYP3A inducer (e.g., rifampin) may decrease AUC and C max of ritlecitinib [see Clinical Pharmacology (12.3) ] , which may result in loss of or reduced clinical response.
Clinically Significant Interactions Affecting Other Drugs CYP3A Substrates Where Small Concentration Changes May Lead to Serious Adverse Reactions Clinical Impact Ritlecitinib is a CYP3A inhibitor.
From the Efavirenz label · effective 2024-03-31
Immunosuppressants: Cyclosporine, tacrolimus, sirolimus and others metabolized by CYP3A ↓ immunosuppressant Dose adjustments of the immunosuppressant may be required.
Close monitoring of immunosuppressant concentrations for at least 2 weeks (until stable concentrations are reached) is recommended when starting or stopping treatment with efavirenz.
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.