Recruiting · registry status

Adjusting medicine balance to study blood pressure drops

Researchers study the ratio of carbidopa to levodopa in people who experience low blood pressure on standing and have Parkinson’s or a related condition.

Testing a treatment or activity · Study reference: NCT06831500

Plain-language introduction written with AI from the registry; not independently checked by a clinician. Read the original details below ↓

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Start (reported actual date): 2025-07-18
Main measurements finished (planned): 2026-11
Study finished (planned): 2026-11

Planned dates can move. A study finishing does not tell us when a paper will be published.

No results summary has been confirmed in the registry records we imported. See connected papers below; we keep checking after recruitment ends.

Changes we have recorded

2026-10-11 — recruiting

These are dates we observed a change, not necessarily the dates it happened.

Papers connected to this study

No connected paper has been found yet. The tracker checks the growing library for study identifiers and registry-linked publications.

Who can join?

Age range not listed · Does not accept healthy volunteers

These are starting points, not the full rules. The research team can tell you whether the study is right for your situation.

Read all the rules for taking part

Sex eligibility reported by registry: all

Inclusion Criteria: 1. Informed consent form signed. 2. Patient over 18 years and under 80 years of age. 3. Patient with Multiple System Atrophy- Parkinsonian type (MSA-P) (confirmed by diagnostic criteria for clinically established and clinically probable multiple system atrophy (11); OR Patient with Parkinson Disease (PD) (12) presenting OH symptoms (getting at least one point at the 3 questions - n° 14, 15 and 16 - of the SCOPA-AUT scale that address orthostatic hypotension symptoms). 4. Patient currently receiving Dopamine-Replacement Therapy (i.e. Levodopa combined with Carbidopa or Benserazide). Exclusion Criteria: 1. Patient unable to stand an overnight (at least 12 hours) withdrawal of their immediate-release DRT (last extended-, delayed-, or controlled-release dosage must be taken minimum 24 hours prior to the test). 2. Patient with known congestive heart failure, grades C and D, NYHA III and IV. 3. Patient with dementia (i.e. major cognitive impairment) associated to MSA-P or PD, 4. Patient with mild cognitive impairment, and unable to provide or understand informed consent, i.e. who does not have full capacity for discernment. 5. Current participation to other clinical trials. 6. Pregnant or lactating woman or willing to become pregnant.

Full study name & original research details

Official study title

A Monocentric, Randomized, Double-blind Study to Assess the Feasibility of Conducting a Full-scale Randomized Controlled Trial (RCT) Assessing the Effect of Carbidopa/Levodopa Ratio on Orthostatic Hypotension (OH) in Multiple System Atrophy - Parkinsonian Type (MSA-P) and Parkinson Disease (PD) Patients (CARBIDOH)

Short title used by the registry

Feasibility Study Assessing the Effect of Carbidopa/Levodopa Ratio on Orthostatic Hypotension in Multiple System Atrophy - Parkinsonian Type and Parkinson Disease.

Original description

This study is aimed at patients with multi-system atrophy - parkinsonian type (P-MSA) or Parkinson's disease (PD) receiving dopaminergic drugs and suffering from orthostatic hypotension (OH). OH is a drop in blood pressure when standing, which can lead to symptoms of dizziness, lightheadedness, a black veil in front of the eyes and, when severe, can lead to fainting. HO is one of the symptoms present in AMS-P and PD. The standard treatment for parkinsonian symptoms of slowness and stiffness is the administration of antiparkinsonian drugs containing dopamine. These dopaminergic drugs always contain 1) levodopa (which is the precursor of dopamine) and 2) an enzyme inhibitor, which may be either benserazide (in the case of Madopar® and its generics) or carbidopa (in the case of Sinemet® or Stalevo® and their generics) and whose role is to potentiate the effect of levodopa. It has long been known that dopaminergic drugs aggravate HO. Through various mechanisms, this worsening of HO is linked as much to levodopa as to the enzyme inhibitor with which it is combined. However, investigators do not know the respective effects of these two molecules on HO. In this study, investigators examine how the ratio of Carbidopa to levodopa affects HO in the various assays of the dopaminergic drug under study.

Conditions reported: Multi-system Atrophy - Parkinsonian Type; Orthostatic Hypotension, Dysautonomic; Parkinson Disease

Registry records for this study

Records are joined using registration identifiers. Titles alone do not establish that two studies are the same.

ClinicalTrials.gov · NCT06831500 ↗ — RECRUITING; checked 2026-10-13
ClinicalTrials.gov · NCT06831500 ↗ — Recruiting; WHO ICTRP processed 2026-02-09; checked 2026-10-13

Study type: Interventional
Interventions: Administration of Carbidopa/levodopa
Phases: PHASE1; PHASE2
Sponsor: Julien Bally
Start date reported by registry: 2025-07-18 (actual)

Registry updated: 2026-01-29 · Status last verified by the registry submitter: 2025-07

Registry records retrieved 2026-10-13 (UTC). Individual records may have older updates. Recruitment and eligibility must be confirmed with the study team.

Contact the research team

Public study contacts supplied to the registry. Ask whether recruitment is still open and what participation involves.

Julien BALLY, Dr PD-MER · +41 79 556 78 19 · julien.bally@chuv.ch

Study locations

Site status can differ from overall study status. “Status not reported” means local availability needs confirmation. Remote participation and travel arrangements must be checked with the team.

Centre Hospitalier Universitaire Vaudois (CHUV)

Lausanne, Canton of Vaud, Switzerland

Recruiting

Matthieu Robitaille, Doctor · +15819826059 · matthieu.robitaille@chuv.ch

Julien Bally, Doctor · +41079 556 78 19 · julien.bally@chuv.ch

Centre Hospitalier Universitaire Vaudois

Lausanne, Canton of Vaud, Switzerland

Recruiting

Julien Bally, Dr. PD MER · +41 79 556 78 19 · julien.bally@chuv.ch

Facility not reported

Switzerland

Status not reported

The original descriptions and participation rules come from the registry. Participation is voluntary and does not guarantee benefit.