Phenobarbital and Ritlecitinib interaction
Phenobarbital and Ritlecitinib: the Ritlecitinib prescribing label flags 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.
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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.