Darunavir and Fosamprenavir interaction
Darunavir and Fosamprenavir: 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 Darunavir (PREZISTA) label · effective 2025-08-29
Co-administration of darunavir and ritonavir and other drugs that inhibit CYP3A, or P-gp may decrease the clearance of darunavir and ritonavir and may result in increased plasma concentrations of darunavir and ritonavir (see Table 10 ).
Other HIV protease inhibitors, except atazanavir [see Drug Interactions (7.4) ] As co-administration with PREZISTA/ritonavir has not been studied, co-administration is not recommended.
From the Fosamprenavir (Fosamprenavir Calcium) label · effective 2026-06-30
Because ritonavir is a CYP2D6 inhibitor, clinically significant interactions with drugs metabolized by CYP2D6 are possible when coadministered with fosamprenavir calcium plus ritonavir.
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.