A Randomized, Placebo-Controlled, Double-Blind, Clinical Trial Evaluating Two Dose Regimens of Rifaximin (550 mg Daily or 550 mg Twice Daily) for Chemoprophylaxis Against Travelers' Diarrhea (TD) Among Active Duty Deployed U.S. and British Military Personnel

IDCRP-080

The purpose of this study is to develop evidence on the relative efficacy of 2 rifaximin chemoprophylaxis regimens for the prevention of Travelers' Diarrhea (TD) in a deployed setting. An additional purpose is to explore the effect of chemoprophylaxis on microbial flora and antimicrobial resistance, and obtain parameter estimates to inform a cost-effectiveness model of chemoprophylaxis in prevention of TD. Information from this study will be used to develop management guidelines for the prevention of TD among deployed (United States (US) and United Kingdom (UK) military personnel. The study will be a multi-site, randomized, placebo-controlled, double-blind, clinical trial among deployed military personnel. The study will test 2 TD chemoprophylaxis regimens (once daily versus twice daily) of the same antibiotic, rifaximin, compared to a placebo. For the proposed chemoprophylaxis study described herein, cohorts of military personnel (US and UK) deploying/traveling overseas will be recruited prior to travel to participate and will undergo enrollment procedures as outlined in study appendices. Subjects who are eligible and agree to participate will be randomized to receive one of 3 regimens: (1) rifaximin 550 mg daily; (2) rifaximin 550 mg twice a day; or (3) placebo, to be taken while deployed. Chemoprophylaxis will be maintained for duration of travel or a predetermined period of up to 6 weeks and at least 2 weeks, which may include a period of up to 5 days of use after return to COO for deployments less than 6 weeks in duration. Clinical and laboratory data will be obtained before, during if available and after deployment/chemoprophylaxis.

2015-11-10

2019-07-01

2019-12-31

Completed

449

Inclusion Criteria: 1. An Institutional Review Board (IRB) / Ethics Committee (EC)-approved informed consent form is signed and dated. 2. Subject is at least 18 years of age 3. Subject's duration of prophylaxis will be least 2 weeks. 4. Subject is capable of and willing to comply with all study procedures and available for the end of study visits and sample collection at COO (within 6 months from start of prophylaxis). 5. Women: Non-nursing and negative urine/serum pregnancy test with understanding (through informed consent process) to avoid pregnancy while on study drug. Sole reliance on oral contraceptives (OCPs) for birth control will not be recommended (see section 6.3.2.1.) Should an individual have a documented surgical sterilization in her medical record, a pregnancy test will not be required. If a volunteer becomes pregnant during the study, the principal investigator will notify the study research monitor and the IRBs. The pregnancy outcome will be followed per IRB and other regulatory requirements for US and UK personnel. 6. (For US Personnel Only). Have consented to participate in TravMil protocol. Exclusion Criteria: 1. Subject received any systemic or gastrointestinal antibiotic in the 7 days prior to enrollment (except anti-malarial prophylaxis agents). 2. Subject has hypersensitivity or allergy to rifaximin or rifampicin. 3. Subject has acute diarrhea within 7 days prior to enrollment 4. Subject has a concomitant disease or condition that could interfere with, or for which treatment could interfere with, the conduct of the study, or could in the opinion of the investigator increase the risk of AEs during the subject's participation in the study 5. Subject is currently taking or plans to take during deployment at least one of the following medications: theophylline or warfarin (Coumadin).

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2023-02-15