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Recruiting Phase 2 NCT05603715

NCT05603715 Pyridostigmine for the Treatment of Constipation in Parkinson Disease

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Clinical Trial Summary
NCT ID NCT05603715
Status Recruiting
Phase Phase 2
Sponsor University of Vermont Medical Center
Condition Parkinson Disease
Study Type INTERVENTIONAL
Enrollment 16 participants
Start Date 2022-08-10
Primary Completion 2026-12-31

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
Pyridostigmine Bromide

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.

This trial targets 16 participants in total. It began in 2022-08-10 with a primary completion date of 2026-12-31.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

Constipation is a common and debilitating non-motor symptom of Parkinson disease (PD) that often precedes the onset of classic motor symptoms by decades. There is no standardized algorithm for managing constipation in this patient population, nor are there dedicated treatments. Studies suggest that constipation can affect quality of life to a significant degree, in many cases just as much as motor symptoms. There is an unmet need for effective treatment options for constipation in this patient population. The goal of this study is to determine the efficacy and safety of pyridostigmine as a treatment for chronic constipation in patients with PD.

Eligibility Criteria

Inclusion Criteria: 1. Age ≥ 18 years 2. Be able to provide signed informed consent 3. Stated ability and willingness to comply with all study procedures 4. Able to take oral medications 5. Females of reproductive potential who are sexually active must be willing to use two of the following highly effective methods of contraception for the duration of study participation and for an additional 28 days after the end of study drug administration: barrier contraception (female condom, diaphragm, cervical cap with/without spermicide), hormonal contraception, or intrauterine device; OR one of the previously mentioned methods AND partner must use barrier contraception (male condom with/without spermicide) 6. Males of reproductive potential who are sexually active must be willing to use the following highly effective methods of contraception for the duration of study participation and for an additional 28 days after the end of study drug administration: barrier contraception (male condom with/without spermicide) AND partner must be postmenopausal, use hormonal contraception, have an intrauterine device, or use barrier contraception (female condom, diaphragm, cervical cap with/without spermicide) 7. Meet United Kingdom Parkinson's Disease Society Brain Bank Criteria: A. Diagnosis of a parkinsonism: * Bradykinesia, plus at least one of the following: * Muscular rigidity * 4-6 Hz resting tremor * Postural stability not caused by primary visual, vestibular, cerebellar or proprioceptive dysfunction B. At least three supportive criteria: * Unilateral onset of symptoms * Rest tremor * Progressive symptoms * Persistent asymmetry affecting the side of onset most * Excellent response to levodopa * Severe levodopa-induced chorea * Levodopa response for five years or more * Clinical course of 10 years or more 8. Fulfill the ROME IV Criteria for Functional Constipation, with a specific requirement that the patient must have three or fewer defecations per week (criterion Ai): * Must include two or more of the following: i. Three or fewer defecations per week ii. Straining during \> 25% of defecations iii. Lumpy or hard stools in \> 25% of defecations iv. Sensation of incomplete evacuation for \> 25% of defecations v. Sensation of anorectal obstruction/blockage for \> 25% of defecations vi. Manual maneuvers to facilitate \> 25% of defecations * Loose stools are rarely present without the use of laxatives * Insufficient criteria for irritable bowel syndrome * Criteria 1-3 must be fulfilled for at least three months with onset of symptoms at least six months prior to diagnosis Exclusion Criteria: 1. Diagnosis of atypical parkinsonism 2. Diagnosis of drug-induced parkinsonism 3. Diagnosis of vascular parkinsonism 4. Known allergy to pyridostigmine bromide or other study drug components 5. Current or recent (within 90 days of enrollment) use of pyridostigmine for any reason 6. History of any bowel surgery 7. History of bladder or bowel obstruction 8. Severe asthma or chronic obstructive pulmonary disease 9. Meet exclusion criteria noted in the UK Parkinson's Disease Society Brain Bank Criteria, at the PI's discretion: A.Exclusion of any of the following: * Repeated strokes with stepwise progression of parkinsonian features * Repeated head injury * Definite encephalitis * Oculogyric crises * Neuroleptic treatment at onset of symptoms * Greater than one affected relative * Sustained remission * Strictly unilateral features after 3 years * Supranuclear gaze palsy * Cerebellar signs * Early severe autonomic involvement * Early severe dementia * Babinski sign * Cerebral tumor or communicating hydrocephalus * Negative response to large doses of levodopa * 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine exposure 10. Significant abnormalities on laboratory analysis (complete blood count, comprehensive metabolic panel, thyroid stimulating hormone) conducted at the screening visit or within the three months prior if available for review 11. Significant abnormalities on screening electrocardiogram conducted at the screening visit or within the three months prior if available for review 12. Positive pregnancy test (if female of child-bearing age) 13. Antibiotic use within two weeks prior to enrollment

Contact & Investigator

Central Contact

Kaysi Herrera Pujols

✉ Kaysi.HerreraPujols@uvmhealth.org

📞 (802) 847-4589

Principal Investigator

Lisa M Deuel, MD

PRINCIPAL INVESTIGATOR

University of Vermont

Frequently Asked Questions

Who can join the NCT05603715 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, studying Parkinson Disease. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT05603715 trial and what does that mean for participants?

Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.

Is NCT05603715 currently recruiting?

Yes, NCT05603715 is actively recruiting participants. Contact the research team at Kaysi.HerreraPujols@uvmhealth.org for enrollment information.

Where is the NCT05603715 trial being conducted?

This trial is being conducted at Burlington, United States.

Who is sponsoring the NCT05603715 clinical trial?

NCT05603715 is sponsored by University of Vermont Medical Center. The principal investigator is Lisa M Deuel, MD at University of Vermont. The trial plans to enroll 16 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: July 2026  ·  Data Methodology