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NCT Number: NCT06718686

Rifaximin SSD in Dementia Trial

Using a new formulation of rifaximin, a non-absorbable antibiotic, to test if it can affect microbes in the gut of patients with dementia favorably.

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Key information

Conditions

Dementia Alzheimer Type Alzheimer Disease Arterial Occlusive Diseases Arteriosclerosis Brain Diseases Cardiovascular Diseases Central Nervous System Diseases Cerebrovascular Disorders Dementia Dementia Associated With Cerebrovascular Disease Dementia, Vascular Intracranial Arterial Diseases Intracranial Arteriosclerosis Leukoencephalopathies Mental Disorders Nervous System Diseases Neurocognitive Disorders Neurodegenerative Diseases Tauopathies Vascular Diseases

Age range

65 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1 / Phase 2

Primary location

Richmond VA Medical Center

Richmond, Virginia, 23249, United States

Location status: Recruiting

Location contact

Haley Obolewicz, RN

CONTACT

[email protected]

804-675-5000 ext. 15705

About this study

Hypothesis: Rifaximin SSD therapy is safe and well tolerated in patients with AD and VaD with beneficial changes in systemic inflammation and systemic biomarkers of dementia due to improvement in microbiota function compared to placebo-related changes in a single-blind, placebo-controlled Phase 1b/2a trial .

Overall Objective: In a single blind placebo-controlled trial in patients with Alzheimer's or vascular dementia, to determine the effect of rifaximin SSD compared to placebo on gut microbial structure and function, cognitive and daily function, and caregiver burden.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Probable Alzheimer's Disease (AD) or Vascular Dementia (VaD) mild or moderate based on Clinical Dementia Rating Scale.
  • Males and Females Age ≥ 65 years
  • Community living with availability of caregiver to accompany participant to study visits and to participate in the study.
  • Able to consent or legal guardian who can consent (with participant assent).
  • Legally authorized representative (LAR) and caregiver for the study is the same individual.
  • Fluency (both participant and caregiver) in written and spoken English to participate in study visits.

Exclusion criteria

  • Dementia not due to AD or VaD
  • Clinically significant agitation or aggression (requiring treatment with antipsychotic medication)
  • Delusions and/or hallucinations
  • Severe psychopathology including major depression
  • Unstable, severe, or poorly controlled medical conditions evident from physical examination or clinical history
  • Visual and/or hearing disorder that prevents completion of neuropsychologic evaluations.
  • Diarrhea
  • Hypersensitivity to rifaximin, components of rifaximin,
  • and any rifamycin antimicrobial agent
  • Antibiotic use in the prior 6 months
  • Taking medications that interact with Rifaximin. P-glycoprotein (P-gp) inhibitor treatment is permitted as long as the use of P-gp inhibitors is discussed with the investigator.
  • History of alcohol and/or drug abuse
  • Participation in another investigational drug trial in the last 30 days

Treatment and study plan

Rifaximin SSD 40 mg IR tablet

Drug

Drug therapy vs placebo

Placebo

Drug

Placebo drug

Primary outcomes

  1. Change in stool and serum short-chain fatty acid levels

    Time frame: 10 weeks

    Change in SCFA in stool and serum in rifaximin SSD phase vs placebo phase

  2. Change in bile acids in stool and serum

    Time frame: 10 weeks

    Change in bile acids in stool and serum in rifaximin SSD phase vs placebo phase

Secondary outcomes

  1. Systemic inflammatory change

    Time frame: 10 weeks

    serum lipopolysaccharide-binding protein (LBP), inflammatory cytokines (IL-6, TNF-α, IL-10, IL-1β) in placebo phase vs Rifaximin SSD phase

  2. Stool microbiome composition

    Time frame: 10 weeks

    16SrRNA microbiome composition and diversity change in placebo vs Rifaximin SSD phase

  3. Change in dementia biomarkers

    Time frame: 10 weeks

    Plasma concentrations of Aβ42 and Aβ40 to calculate amyloid-β (Aβ)42/40 ratio and plasma concentration of phospho-tau (p-tau)181 in placebo vs Rifaximin SSD phase

  4. MMSE

    Time frame: 10 weeks

    Change in MMSE between the 2 phases

  5. Cognitive testing using Psychometric Hepatic Encephalopathy Score

    Time frame: 10 weeks

    Change in PHES in placebo vs rifaximin SSD phase

  6. Clinical Dementia Rating - Sum of Boxes (CDR-SB)

    Time frame: 10 weeks

    Change in CDR-SB in placebo vs Rifaximin SSD phase

  7. EncephalApp Stroop performance

    Time frame: 10 weeks

    Change in off time and on time in seconds between placebo and rifaximin SSD phases

  8. Critical flicker fusion analysis

    Time frame: 10 weeks

    change in threshold to see CFF fusion in rifaximin SSD vs placebo phases

  9. Katz Index of Independence in Activity of Daily Living (ADL)

    Time frame: 10 weeks

    change in the score above judged by caregivers in placebo vs Rifaximin SSD phase

  10. Lawton-Brody Instrumental Activities of Daily Living (IADL)

    Time frame: 10 weeks

    Change in instrument score above by caregivers in rifaximin SSD vs placebo phase

  11. Zarit Burden Interview short form

    Time frame: 10 weeks

    Change in instrument score above by caregivers in rifaximin SSD vs placebo phase

  12. Sickness Impact profile

    Time frame: 10 weeks

    change in score of the QOL instrument above in placebo vs rifaximin SSD phases

  13. PROMIS-29

    Time frame: 10 weeks

    change in score of the QOL instrument above in placebo vs rifaximin SSD phases

  14. Safety

    Time frame: 10 weeks

    Serious adverse event rates in placebo versus rifaximin SSD phases

Study contacts

Contact information is provided by the study sponsor or research team.

Haley Obolewicz, RN

CONTACT

[email protected]

804-675-5705

Jasmohan S Bajaj, MD

CONTACT

[email protected]

804-675-5802

Sponsors and collaborators

Lead sponsor

Jasmohan Bajaj

Fed

Collaborators

  • Bausch Health Americas, Inc.

Registry information

Official study title

Rifaximin in Dementia Trial (RIDE): Gut-Brain Modulation With Rifaximin SSD in Dementia

Acronym: RIDE

Important dates

Study start
2024
Primary completion
2027
Study completion
2027
First posted
Dec 5, 2024
Registry last updated
Apr 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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