Fosamprenavir and Itraconazole interaction
Fosamprenavir and Itraconazole: 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 Fosamprenavir (Fosamprenavir Calcium) label · effective 2026-06-30
Fosamprenavir calcium/ritonavir: High doses of ketoconazole or itraconazole (greater than 200 mg/day) are not recommended.
Antifungals: Ketoconazole a , itraconazole ↑ Ketoconazole ↑ Itraconazole Increase monitoring for adverse events.
Fosamprenavir calcium: Dose reduction of ketoconazole or itraconazole may be needed for patients receiving more than 400 mg ketoconazole or itraconazole per day.
From the Itraconazole (Tolsura) label · effective 2025-04-23
Antivirals Cobicistat Darunavir (ritonavir-boosted) Elvitegravir (ritonavir-boosted) Fosamprenavir (ritonavir-boosted) Indinavir Ritonavir Saquinavir Monitor for adverse reactions.
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.
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.
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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.