Efavirenz and Larotrectinib interaction
Efavirenz and Larotrectinib: the Larotrectinib 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 Larotrectinib (VITRAKVI) label · effective 2026-05-22
Strong CYP3A4 Inhibitors: Avoid coadministration of strong CYP3A4 inhibitors with VITRAKVI.
Strong CYP3A4 Inducers: Avoid coadministration of strong CYP3A4 inducers with VITRAKVI.
Avoid coadministration of VITRAKVI with strong CYP3A4 inhibitors, including grapefruit or grapefruit juice.
If coadministration of strong CYP3A4 inhibitors cannot be avoided, modify VITRAKVI dose as recommended [see Dosage and Administration (2.5) ] .
Avoid coadministration of VITRAKVI with strong CYP3A4 inducers, including St.
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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.