rifaximin, Xifaxan

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Jay W. Marks, MD
    Jay W. Marks, MD

    Jay W. Marks, MD

    Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

woman with abdominal pain

Many of these side effects are also symptoms of traveler's diarrhea which rifaximin is used for treating. Rifaximin also causes allergic reactions, rash, and itching. Like other antibiotics rifaximin can alter the normal bacteria in the colon and encourage overgrowth of some bacteria such as Clostridium difficile which causes inflammation of the colon (pseudomembranous colitis). Patients who develop signs of pseudomembranous colitis after starting rifaximin (diarrhea, fever, abdominal pain, and possibly shock,) should contact their physician immediately.

PRESCRIPTION: Yes

GENERIC AVAILABLE: No

PREPARATIONS: Tablets: 200 and 550 mg

STORAGE: Rifaximin should be stored at room temperature at 15 C - 30 C (59 F - 86 F).

DOSING: The recommended dose for traveler's diarrhea is 200 mg 3 times daily for 3 days and the recommended dose for hepatic encephalopathy is 550 mg twice daily. Rifaximin may be administered with or without meals.

DRUG INTERACTIONS: Rifaximin does not interact with oral contraceptives and does not significantly interact with midazolam. Rifaximin has a low risk of drug interactions because it is poorly absorbed into the blood stream, and it does not significantly affect liver enzymes that break down most drugs.

PREGNANCY: The safety of rifaximin in pregnant women has not been adequately evaluated.

NURSING MOTHERS: It is not known whether rifaximin is excreted in breast milk.

Medically reviewed by Eni Williams, PharmD

REFERENCE: FDA Prescribing information for Xifaxan

Medically Reviewed by a Doctor on 3/30/2015

Quick GuideDigestive Disorders: Common Misconceptions

Digestive Disorders: Common Misconceptions
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