Drug interactions
Itraconazole + Nirmatrelvir
Severity: Moderate
Itraconazole and Nirmatrelvir: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Nirmatrelvir is a CYP3A4 inhibitor and, together with ritonavir, raises itraconazole concentrations. This increases the risk of itraconazole toxicity such as edema, heart failure exacerbation, hypokalemia and hepatotoxicity.
What this interaction means in plain words
Itraconazole and Nirmatrelvir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Itraconazole belongs to Anti Fungals; Nirmatrelvir belongs to Anti Virals.
Why it happens
Inhibition of CYP3A4 metabolism of itraconazole by nirmatrelvir and ritonavir.
What to do
Limit itraconazole to no more than 200 mg/day during the short nirmatrelvir course. Monitor for itraconazole adverse effects.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole Contraindicated
Other interactions of Nirmatrelvir
- Alfuzosin + Nirmatrelvir Contraindicated
- Amiodarone + Nirmatrelvir Contraindicated
- Apalutamide + Nirmatrelvir Contraindicated
- Carbamazepine + Nirmatrelvir Contraindicated
- Colchicine + Nirmatrelvir Contraindicated
- Dronedarone + Nirmatrelvir Contraindicated
Frequently asked questions
Can I take Itraconazole with Nirmatrelvir?
MediHelp rates the interaction as moderate. Itraconazole and Nirmatrelvir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Nirmatrelvir is a CYP3A4 inhibitor and, together with ritonavir, raises itraconazole concentrations. This increases the risk of itraconazole toxicity such as edema, heart failure exacerbation, hypokalemia and hepatotoxicity.
How serious is the interaction between Itraconazole and Nirmatrelvir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit itraconazole to no more than 200 mg/day during the short nirmatrelvir course. Monitor for itraconazole adverse effects.
What other medicines interact with Itraconazole?
MediHelp also lists interactions of Itraconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Itraconazole page.
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