Study Comparing Rifaximin With Xifaxan 200 mg in Traveler's Diarrhea

A Randomized, Double-Blind, Placebo-Controlled, Parallel Design, Multicenter, Bioequivalence Study With Clinical Endpoint Comparing Rifaximin 200-mg Tablets With Xifaxan® 200-mg Tablets in the Treatment of Travelers' Diarrhea

The primary objective is to demonstrate rifaximin 200 milligrams (mg) tablets (test) and Xifaxan® 200 mg tablets (reference) are clinically bioequivalent with respect to the clinical cure rates when administered 3 times a day (TID) for 3 days in participants with travelers' diarrhea.

This is a randomized, placebo-controlled bioequivalent study with a clinical endpoint in the treatment of travelers' diarrhea. After 3 unformed stools are recorded within the 24 hours immediately preceding randomization, participants are to be randomized to receive the generic rifaximin 200 mg oral tablet, Xifaxan (the reference listed drug)200 mg oral tablet, or placebo 3 times daily for 3 days (that is; on Days 1, 2, and 3).

Inclusion Criteria:

1. Adult male or nonpregnant female aged ≥18 years non-indigenous travelers (for example; visiting students/faculty or international tourists) affected by naturally acquired acute diarrhea. Diarrhea is defined as the passage of at least 3 unformed stools in a 24-hour period. Stools are classified as formed (retains shape), soft (assumes shape of container), or watery (can be poured). When using this classification, both soft and watery stools are unformed and abnormal.

2. At least 3 unformed stools recorded within the 24 hours immediately preceding randomization.

3. At least 1 of the following signs and symptoms of enteric infection:

   • abdominal pain or cramps
   • nausea
   • vomiting
   • fecal urgency
   • excessive gas/flatulence
   • tenesmus

4. Women of child-bearing potential have a negative pregnancy test prior to beginning therapy and agree to use effective contraceptive methods during the study.

Exclusion Criteria:

1. Pregnant, breast feeding, or planning a pregnancy.

2. Immediately prior to randomization, acute diarrhea for >72 hours.

3. Presence of:

   • fever (≥100 degrees fahrenheit [°F] or ≥37.8 degrees celsius [°C]), or
   • hematochezia (blood in stool), or
   • clinical findings suggesting moderate or severe dehydration.

4. Active, uncontrolled, or clinically significant diseases or disorders of the heart, lung, kidney, gastrointestinal (GI) tract (other than infectious diarrhea in travelers), or central nervous system.

5. Administration of any of the following:

   • any antimicrobial agents with an expected activity against enteric bacterial pathogens within 7 days preceding randomization
   • more than 2 doses of a symptomatic antidiarrheal compound such as antimotility agents, absorbent agents, and antisecretory agents within 8 hours preceding randomization

6. Use of any drug such as aspirin or ibuprofen (Advil), which can cause GI bleeding. Acetaminophen (Tylenol) or paracetamol is acceptable.