Ketoconazole and Lorlatinib interaction
Ketoconazole and Lorlatinib: 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 Ketoconazole label · effective 2026-07-07
Therefore, administration of potent enzyme inducers of CYP3A4 with ketoconazole tablets is not recommended.
Coadministration of ketoconazole tablets with potent enzyme inducers of CYP3A4 may decrease the bioavailability of ketoconazole to such an extent that efficacy may be reduced.
From the Lorlatinib (Lorbrena) label · effective 2026-06-26
• Strong CYP3A Inhibitors : Avoid concomitant use; reduce LORBRENA dose if concomitant use cannot be avoided.
Strong CYP3A Inhibitors Avoid concomitant use of LORBRENA with a strong CYP3A inhibitor.
Concomitant use with a strong CYP3A inhibitor increased lorlatinib plasma concentrations [see Clinical Pharmacology (12.3) ] , which may increase the incidence and severity of adverse reactions of LORBRENA.
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.