Itraconazole and Ivacaftor interaction

Itraconazole and Ivacaftor: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Itraconazole (Tolsura) label · effective 2025-04-23

Major

Lumacaftor/Ivacaftor Not recommended 2 weeks before, during, and 2 weeks after TOLSURA treatment.

Drug interactionsnames IvacaftorView label on DailyMed
Major

Miscellaneous Drugs and Other Substances Lumacaftor/Ivacaftor Not recommended 2 weeks before, during, and 2 weeks after TOLSURA treatment.

Drug interactionsnames IvacaftorView label on DailyMed
Moderate

Alitretinoin (oral) Cabergoline Cannabinoids Cinacalcet Ivacaftor Monitor for adverse reactions.

Drug interactionsnames IvacaftorView label on DailyMed
Minor

Cardiac Dysrhythmias : Life-threatening cardiac dysrhythmias and/or sudden death have occurred in patients using certain drugs that are metabolized by human CYP450 enzymes concomitantly with oral itraconazole and/or other CYP3A4 inhibitors.

Warnings and precautionsby drug classView label on DailyMed
Minor

Cardiac Dysrhythmias Life-threatening cardiac dysrhythmias and/or sudden death have occurred in patients using drugs such as, pimozide, methadone, or quinidine concomitantly with oral itraconazole and/or other CYP3A4 inhibitors.

Warnings and precautionsby drug classView label on DailyMed

From the Ivacaftor (Kalydeco) label · effective 2026-03-23

Moderate

Based on simulations of these results, a reduction of the KALYDECO dosage is recommended for patients aged 6 months and older taking concomitant strong CYP3A inhibitors, such as ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, and clarithromycin.

Drug interactionsnames ItraconazoleView label on DailyMed
Moderate

Potential for other drugs to affect ivacaftor CYP3A inhibitors: Reduce KALYDECO dosage in patients aged 6 months and older when co-administered with strong CYP3A inhibitors (e.g., ketoconazole) or moderate CYP3A inhibitors (e.g., fluconazole).

Drug interactionsby drug classView label on DailyMed

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Not 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.