Itraconazole and Nirmatrelvir and ritonavir interaction

Itraconazole and Nirmatrelvir and ritonavir: 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 Nirmatrelvir and ritonavir (Paxlovid) label · effective 2026-02-19

Major

Antifungals voriconazole ↓ voriconazole Avoid concomitant use of voriconazole. ketoconazole, isavuconazonium sulfate, itraconazole ↑ ketoconazole ↑ isavuconazonium sulfate ↑ itraconazole Refer to the ketoconazole, isavuconazonium sulfate, and itraconazole prescribing information for further information. ↑ nirmatrelvir/ritonavir A nirmatrelvir/ritonavir dose reduction…

Drug interactionsnames ItraconazoleView label on DailyMed

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

Moderate

Cobicistat Elvitegravir (ritonavir-boosted) Ritonavir Saquinavir (unboosted) Monitor for adverse reactions.

Drug interactionsnames Nirmatrelvir and ritonavirView label on DailyMed
Moderate

Antivirals Cobicistat Darunavir (ritonavir-boosted) Elvitegravir (ritonavir-boosted) Fosamprenavir (ritonavir-boosted) Indinavir Ritonavir Saquinavir Monitor for adverse reactions.

Drug interactionsnames Nirmatrelvir and ritonavirView label on DailyMed
Minor

For, cobicistat, elvitegravir, indinavir, ritonavir, and saquinavir, see also Table 4 .

Drug interactionsnames Nirmatrelvir and ritonavirView 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

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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.