Fosamprenavir and Posaconazole interaction
Fosamprenavir and Posaconazole: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Posaconazole (NOXAFIL) label · effective 2026-02-13
Fosamprenavir, metoclopramide Monitor for breakthrough fungal infections ( 7.1 )
Fosamprenavir Mechanism and Clinical Effect(s) Concomitant use of Noxafil with fosamprenavir may lead to decreased posaconazole plasma concentrations [see Clinical Pharmacology (12.3) ], which may reduce effectiveness of posaconazole.
Prevention or Management If concomitant use of posaconazole with fosamprenavir is needed, monitor closely for breakthrough fungal infections.
Anti-HIV Drugs that are CYP3A4 Substrates Mechanism and Clinical Effect(s) Ritonavir and atazanavir are CYP3A4 substrates and posaconazole increased plasma concentrations of these drugs [see Clinical Pharmacology (12.3) ].
Effects of Noxafil and Noxafil PowderMix on Other Drugs Posaconazole is a strong CYP3A4 inhibitor.
From the Fosamprenavir (Fosamprenavir Calcium) label · effective 2026-06-30
Antifungals: Ketoconazole a , itraconazole ↑ Ketoconazole ↑ Itraconazole Increase monitoring for adverse events.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.