Home » Drug Information » FDA Approved Drugs » 2004
Medical Areas: Immunology | Hepatology (Liver, Pancreatic, Gall Bladder)
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The following drug information is obtained from various newswires, published
medical journal articles, and medical conference presentations.
Company: Salix Pharmaceuticals
Approval Status: Approved May 2004
Treatment Area: Travelers’ Diarrhea
Xifaxan (rifaximin) is a semi-synthetic,
nonsystemic antibiotic in a 200-mg tablet form. It is approved in
17 countries and was first used in Italy over 17 years ago, with
over 500 million tablets prescribed.
Xifaxan is indicated for the treatment of travelers’ diarrhea
caused by noninvasive strains of Escherichia coli in
patients 12 years old and older.
The recommended dosage of Xifaxan is one 200 mg tablet taken
three times a day for three days.
FDA approval of Xifaxan was based on two randomized,
multi-center, double-blind, placebo controlled studies in adult
subjects with travelers’ diarrhea. The studies enrolled 320
subjects at multiple sites in Mexico, Peru, India, Guatemala, and
Kenya. Subject’s stool specimens were collected before and after
the end of treatment to identify enteric pathogens, which was
predominantly Escherichia coli. The primary efficacy
endpoint was time to last unformed stool (TLUS) which is defined as
the time to the last unformed stool passed, after which clinical
cure was declared.
Results showed that the duration of diarrhea was significantly
shorter in patients treated with rifaximin (32.5 hours) than in the
placebo group (58.6 hours). In addition, more subjects treated with
rifaximin (99) were classified as being clinical cured than
subjects treated with placebo (78). Although rifaximin had
microbiologic activity similar to placebo, it demonstrated a
clinically significant reduction in duration of diarrhea and a
higher clinical cure rate than placebo.
The majority of the rifaximin- treated subjects who had
Campylobacter jejuni isolated as a sole pathogen at
baseline failed treatment with a clinical cure rate of 23.5%
(4/17). These results were no different from placebo and the
microbiologic eradication rates for subjects with Campylobacter
jejuni isolated at baseline were much lower than the
eradication rates seen for Escherichia coli.
Adverse events associated with the use of Xifaxan may include
(but are not limited to) the following:
- Abdominal Pain
- Rectal Tenesmus
- Defecation Urgency
Mechanism of Action
Rifaximin, the active ingredient in Xifaxan, is a rifamycin
derivative and non-systemic, gastrointestinal site-specific
Di Stefano M, Miceli E, Armellini E, Missanelli A,
Corazza GR. Probiotics and functional abdominal bloating.
J Clin Gastroenterol. 2004 Jul; 38(6 Suppl): S102-3.
Latella G, Pimpo MT, Sottili S, Zippi M, Viscido A,
Chiaramonte M, Frieri G. Rifaximin improves symptoms of
acquired uncomplicated diverticular disease of the colon. Int J
Colorectal Dis. 2003 Jan; 18(1): 55-62. Epub 2002 May 09.
Steffen R, Sack DA, Riopel L, Jiang ZD, Sturchler M,
Ericsson CD, Lowe B, Waiyaki P, White M, DuPont HL.
Therapy of travelers' diarrhea with rifaximin on various
continents.Am J Gastroenterol. 2003 May; 98(5):
For additional information regarding Xifaxan or Travelers'
diarrhea, please contact The Xifaxan Web Site