Patients should be advised that XIFAXAN™ Tablets may be taken with or without food. Patients should be advised that XIFAXAN™ Tablets should be discontinued if their diarrhea persists more than 24-48 hours or worsens, or if they have fever and/or blood in the stool that they should seek medical care.
Although in vitro studies demonstrated the potential of rifaximin to interact with cytochrome P450 3A4 (CYP3A4), a clinical drug-drug interaction study demonstrated that rifaximin did not significantly affect the pharmacokinetics of midazolam either presystemically or systemically. An additional clinical drug-drug interaction study showed no effect of rifaximin on the presystemic metabolism of an oral contraceptive containing ethinyl estradiol and norgestimate. Therefore, clinical interactions with drugs metabolized by human cytochrome P450 isoenzymes are not expected.
XIFAXAN™ Tablets are contraindicated in patients with a hypersensitivity to rifaximin, any of the rifamycin antimicrobial agents, or any of the components in XIFAXAN™ Tablets.