Erlotinib and Ritonavir interaction
Erlotinib and Ritonavir: the Erlotinib 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 Erlotinib label · effective 2024-06-26
Avoid co-administering erlotinib with strong CYP3A4 inhibitors (e.g., boceprevir, clarithromycin, conivaptan, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telithromycin, voriconazole, grapefruit or grapefruit juice) or a combined CYP3A4 and CYP1A2 inhibitor (e.g., ciprofloxacin).
Reduce the erlotinib dosage when co-administering with a strong CYP3A4 inhibitor or a combined CYP3A4 and CYP1A2 inhibitor if co-administration is unavoidable [see Dosage and Administration (2.4) ].
Avoid smoking tobacco (CYP1A2 inducer) and avoid concomitant use of erlotinib with moderate CYP1A2 inducers (e.g., teriflunomide, rifampin, or phenytoin).
Increase the erlotinib dosage in patients that smoke tobacco or when co-administration with moderate CYP1A2 inducers is unavoidable [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3) ].
CYP3A4 Inhibitors Co-administration of erlotinib with a strong CYP3A4 inhibitor or a combined CYP3A4 and CYP1A2 inhibitor increased erlotinib exposure.
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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.