Fosamprenavir and Omeprazole interaction
Fosamprenavir and Omeprazole: 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 Fosamprenavir (Fosamprenavir Calcium) label · effective 2026-06-30
Proton pump inhibitors: Esomeprazole a , lansoprazole, omeprazole, pantoprazole, rabeprazole Fosamprenavir calcium: ↔ Amprenavir ↑ Esomeprazole Proton pump inhibitors can be administered at the same time as a dose of fosamprenavir calcium with no change in plasma amprenavir concentrations.
From the Omeprazole (Prilosec) label · effective 2024-03-19
• Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir and nelfinavir) when used concomitantly with omeprazole may reduce antiviral effect and promote the development of drug resistance [see Clinical Pharmacology ( 12.3 )].
• Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with omeprazole may increase toxicity [see Clinical Pharmacology ( 12.3 )].
CYP2C19 or CYP3A4 Inhibitors Clinical Impact: Increased exposure of omeprazole [see Clinical Pharmacology ( 12.3 )] .
Table 3: Clinically Relevant Interactions Affecting Drugs Co-Administered with Omeprazole and Interaction with Diagnostics Antiretrovirals Clinical Impact: The effect of PPIs on antiretroviral drugs is variable.
• There are other antiretroviral drugs which do not result in clinically relevant interactions with omeprazole.
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.