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U.S. Department of Health and Human Services

Safety

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Xifaxan (rifaximin) Tablets

Detailed View: Safety Labeling Changes Approved By FDA Center for Drug Evaluation and Research (CDER)

 

March 2014

Summary View

WARNINGS AND PRECAUTIONS

Concomitant use with P-glycoprotein Inhibitors
  • Concomitant administration of drugs that are P-glycoprotein inhibitors with rifaximin can substantially increase the systemic exposure to rifaximin. Caution should be exercised when concomitant use of rifaximin and a P-glycoprotein inhibitor such as cyclosporine is needed. In patients with hepatic impairment, a potential additive effect of reduced metabolism and concomitant P-glycoprotein inhibitors may further increase the systemic exposure to rifaximin

DRUG INTERACTIONS

Concomitant P-glycoprotein inhibitors
  • An in vitro study suggested that rifaximin is a substrate of P-glycoprotein. Co-administration of cyclosporine, a potent P-glycoprotein inhibitor, with rifaximin resulted in 83-fold and 124-fold increases in rifaximin mean Cmax and AUC8 in healthy subjects. The clinical significance of this increase in systemic exposure is unknown