---
title: Test tenapanor for Parkinson constipation
nct_id: NCT06460038
phase: PHASE2
status: RECRUITING
sponsor: Cedar Valley Digestive Health Center
study_type: INTERVENTIONAL
canonical_url: "https://parkinsonspathways.com/trial/NCT06460038"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT06460038"
last_fetched: "2026-05-10T14:07:50.516Z"
source: "Parkinson's Pathways (curated)"
---
# Test tenapanor for Parkinson constipation

**Goal (in five words):** Test tenapanor for Parkinson constipation

**Official Title:** Efficacy and Safety of Tenapanor in Synucleinopathy-Related Constipation

**Trial ID:** [NCT06460038](https://clinicaltrials.gov/study/NCT06460038)

## Key Facts

- **Phase:** PHASE2
- **Status:** RECRUITING
- **Study Type:** INTERVENTIONAL
- **Sponsor:** Cedar Valley Digestive Health Center
- **Target Enrollment:** 30 participants
- **Start Date:** 2025-01-01
- **Completion Date:** 2026-12
- **Conditions:** Synucleinopathy, Parkinson's Disease
- **Interventions:** Tenapanor, Placebo
- **Intervention Types:** DRUG

## Summary For Families

The goal is to see if tenapanor can safely increase bowel movements and soften stools to relieve the chronic constipation many people with synucleinopathies like Parkinson's experience. The pill blocks the intestinal NHE3 sodium/hydrogen exchanger on gut lining cells, so less sodium is absorbed and more water stays in the bowel to soften stool and boost spontaneous bowel movements, and because it acts mainly in the gut with minimal systemic absorption it is not expected to interfere with levodopa. The trial is enrolling people 50 to 89 years old with Parkinson's at Hoehn and Yahr stages 1,3 who have chronic constipation verified during a 2-week screening (≤5 spontaneous BMs and ≤2 complete spontaneous BMs per week, Bristol stool form ≤3); those with IBS-D, structural GI disease, significant liver or kidney problems, pregnancy, or primary dyssynergic defecation are excluded.

## Eligibility

- **Minimum age:** 50 Years
- **Maximum age:** 89 Years
- **Sex:** ALL

### Full 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.
```

## Locations (1)

- Cedar Valley Digestive Health Center, Waterloo, Iowa, United States _(42.4928, -92.3430)_
  - Harichandana Punukula, PharmD, MS — (CONTACT) — 319-888-8275 — hpunukula@cvmspc.com

## Central Contacts

- Richard A. Manfready, MD, AM, FACP — (CONTACT) — (319) 235-5390 — rman@alum.mit.edu
- Harichandana Punukula, PharmD, MS — (CONTACT) — 319-888-8270 — hpunukula@cvmspc.com

---

*Canonical: https://parkinsonspathways.com/trial/NCT06460038*  
*HTML version: https://parkinsonspathways.com/trial/NCT06460038*  
*Source data: https://clinicaltrials.gov/study/NCT06460038*