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Efficacy of Rifaximin With NAC in IBS-D

ConditionsIBS (Irritable Bowel Syndrome)IBS-D (Diarrhea-predominant)
Trial statusRecruiting
Trial phasePhase 2
Trial typeInterventional
Biological sexAll
Age18+
SponsorMark Pimentel, MD

About this trial

The purpose of this study is to examine the effectiveness of using a combination of a drug, rifaximin and a dietary supplement, N-acetyl-L-cysteine (NAC), to treat patients with irritable bowel syndrome with diarrhea (IBS-D). Rifaximin is one of the standard treatments for IBS-D and is FDA approved. While rifaximin is safe and effective for treating symptoms in patients with IBS-D, many patients find that their symptoms may not completely resolve, or may come back after a period of time.

This research study is designed to test the investigational use of a combination of rifaximin and NAC. The combination of rifaximin and NAC is not approved by the U.S. Food and Drug Administration (FDA) for the treatment of IBS-D, and the effects of taking both medications together are unknown. However, the two medications are approved for use separately, as detailed below.

Rifaximin is the only antibiotic approved by the FDA for the treatment of IBS-D. Rifaximin (at a dose of 550 mg by mouth three times daily for 14 days) is approved by the FDA for the treatment of IBS-D. Rifaximin (at a dose of 200 mg per mouth three times daily for 3 days) is FDA approved for the treatment of traveler's diarrhea. Rifaximin at a dose of 200 mg per mouth three times daily is not approved by the FDA for the treatment of IBS-D.

NAC is approved by the FDA to treat acetaminophen overdose (72-hour oral and 21-hour intravenous (IV) regimens), and for use in breaking up mucus in the lungs in patients with chronic obstructive pulmonary disease (COPD) and other lung conditions such as bronchitis. NAC is also available over-the-counter in 600 mg and 900 mg capsules as a dietary supplement, although over-the-counter use is not regulated by the FDA. This study will utilize the 600 mg dietary supplement capsules.

The Investigators want to know if using a combination of rifaximin and NAC will give better results in decreasing IBS-D symptoms than using rifaximin alone. As NAC is used to break up mucus in the lungs, and the Investigators want to see if this can also break up the mucus layer in the small intestine, and therefore potentially increase the effectiveness of rifaximin. The Investigators will be testing 2 doses to determine which dose is most effective.

participants are being asked to take part in this research study because participants were diagnosed with IBS-D.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Male or non-pregnant, non-lactating female patients ≥ 18 years of age

Diagnosed with IBS confirmed by the Rome IV criteria, with associated symptoms of diarrhea as noted below in 4(b).

Do not have adequate relief of IBS symptoms of abdominal pain, stool consistency or stool frequency

Weekly average score of worst daily abdominal pain >3.0 on a 0-10 point scale

Disqualifiers

Less than 3 bowel movements a week,

Hard or lumpy stools, and

Excessive straining during a bowel movement.

History of inflammatory bowel disease, celiac disease, GI surgery (except cholecystectomy and/or appendectomy)

Trial design

Design model

Parallel

Treatments tested in this trial

  • rifaximin 66mg + N-acetylcysteine 560mg three times daily

    Drug

    RNIB21 containing rifaximin 66mg + N-acetylcysteine 560mg three times daily

  • RNIB21 containing rifaximin 132mg + N-acetylcysteine 560mg three times daily

    Drug

    RNIB21 containing rifaximin 132mg + N-acetylcysteine 560mg three times daily

  • Placebo

    Drug

    placebo three times daily

Treatment groups

225 Participants
are divided into 3 treatment groups
Group A: low dose for IBS-DExperimental treatment 1 intervention
Group B: high dose for IBS-DExperimental treatment 1 intervention
Group C: placeboPlacebo comparator 1 intervention

Trial outcomes

Primary outcomes

1

stool consistency

A 50% reduction in the number of days per week with at least one stool consistency of Type 6 or 7 on the BSS compared to baseline, for at least 2 of the 4 weeks of the PEP

Time frame
2 weeks
2

Abdominal pain

Abdominal pain will be self-reported on a daily basis using an 11-point (0-10) pain scale, where 10 represent the highest pain.;A 30% improvement compared to baseline on the weekly average score of worst daily abdominal pain for at least 2 of the 4 weeks of the primary evaluation period .

Time frame
2 weeks

Secondary outcomes

1

overall response

Overall response: Proportion of patients that achieve a weekly response during at least 50% of the weeks of treatment and follow up (i.e. 7 of 14 weeks

Time frame
up to 7 weeks of 14 weeks
2

stool frequency

Stool frequency as number of bowel movements per day averaged on a weekly basis, versus baseline determined during the PEP

Time frame
2 weeks

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Mark Pimentel, MD

Lead sponsor

Cedars-Sinai Medical Center

Sponsor institution

Source ClinicalTrials.gov
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