Does Fosamprenavir Interact with Rifampin?
CDI records a contraindicated classification for Fosamprenavir and Rifampin. The stored summary is: Concomitant use is contraindicated. Rifampin decreases fosamprenavir AUC by 82%. The mechanism involves cyp3a4 induction; auc decreased by 82%. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This record was extracted from drug labeling through openFDA. NIH/NLM RxNorm is used for drug identities. The summary and severity classification are CDI's processed information, not a verbatim source quotation. Product, route, and patient circumstances matter.
- Severity
- Contraindicated
- Rifampin Class
- Rifamycin Antibacterial
- Management
- Do not take together
- Data Source
- U.S. FDA via OpenFDA
Recorded Mechanism
CYP3A4 induction; AUC decreased by 82%
What To Tell Your Doctor or Pharmacist
If you are taking Fosamprenavir and your doctor is considering prescribing Rifampin (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask about alternative medications that do not interact with your current regimen
- Ask how frequently you should be monitored while these are co-prescribed
- Never stop or change either medication without first consulting your healthcare provider