Treatment for constipation related to Parkinson's disease

Efficacy and Safety of Tenapanor in Synucleinopathy-Related Constipation

Phase 2 Interventional Cedar Valley Digestive Health Center · NCT06460038

This study is testing if a new medication called tenapanor can help people with Parkinson's disease who have constipation feel better by improving their bowel movements.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment30 (estimated)
Ages50 Years to 89 Years
SexAll
SponsorCedar Valley Digestive Health Center Academic / other
Locations1 site (Waterloo, Iowa)
Trial IDNCT06460038 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effectiveness of tenapanor, a medication, in treating constipation associated with synucleinopathy in patients with Parkinson's disease. It is a randomized, double-blind, placebo-controlled study, meaning participants will be randomly assigned to receive either tenapanor or a placebo without knowing which one they are receiving. The study aims to assess changes in bowel movement frequency and stool consistency over a specified period. Participants will undergo a screening process to confirm eligibility based on their bowel movement patterns and overall health.

Who should consider this trial

Good fit: Ideal candidates for this study are individuals aged 50-89 with a diagnosis of Parkinson's disease in early to moderate stages and experiencing specific constipation symptoms.

Not a fit: Patients with functional diarrhea, inflammatory bowel disease, or significant liver or kidney dysfunction may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve bowel function and quality of life for patients suffering from constipation due to Parkinson's disease.

How similar studies have performed: While this approach is novel in the context of synucleinopathy-related constipation, similar studies have shown promise in treating constipation with other interventions.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria

1. Age 50-89 years.
2. Diagnosis of PD within Hoehn and Yahr stages 1-3, confirmed by a neurologist per International Parkinson and Movement Disorder Society criteria.
3. Average weekly stool frequency of ≤5 spontaneous bowel movements (SBMs) and ≤2 complete spontaneous bowel movements (CSBMs) over the past 6 months. These criteria will be verified during a 2-week screening period.
4. Stool consistency ≤3 on the Bristol Stool Form Scale (BSFS). This criterion will be verified during a 2-week screening period.
5. Agreement to use contraception, if applicable.

Exclusion Criteria

1. Functional diarrhea or IBS-D/M based on Rome IV Criteria.
2. Symptomatic structural GI abnormalities or inflammatory bowel disease.
3. Significant hepatic (ALT or AST ≥ 2.5x the upper limit of normal) or renal (serum creatinine \>2mg/dl) dysfunction.
4. Pregnancy or lactation.
5. Diagnosis of primary dyssynergic defecation by anorectal manometry.

Where this trial is running

Waterloo, Iowa

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions SynucleinopathyParkinson's DiseasetenapanorsynucleinopathyParkinson's diseaseconstipation
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.