Actively Recruiting
Randomized Double-blind Study of Carbidopa/Levodopa Ratios on Orthostatic Hypotension in Multiple System Atrophy - Parkinsonian Type and Parkinson Disease
Led by Julien Bally · Updated on 2026-01-29
36
Participants Needed
2
Research Sites
N/A
Total Duration
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AI-Summary
What this Trial Is About
This research focuses on patients with multi-system atrophy - parkinsonian type (MSA-P) or Parkinson's disease (PD) who are taking dopaminergic drugs and experiencing orthostatic hypotension (OH). OH is a condition where blood pressure drops upon standing, causing symptoms like dizziness, lightheadedness, and fainting. The study aims to understand how different ratios of carbidopa to levodopa in these drugs affect OH, as current knowledge does not clarify the individual impact of these components on the symptom. Participants will receive single oral doses of carbidopa/levodopa combinations at three different ratios: 1:10 (20 mg carbidopa/200 mg levodopa), 1:4 (50 mg carbidopa/200 mg levodopa), and 1:2 (100 mg carbidopa/200 mg levodopa). These doses are administered in a randomized, double-blind manner across three visits in varying order. The study evaluates the feasibility of conducting a larger randomized controlled trial based on this dosing strategy. During the study, participants will undergo beat-by-beat orthostatic tests (Schellong tests) before and after taking each dose to monitor blood pressure changes related to OH. The primary outcome is to assess the feasibility of a future larger trial over a five-week period from enrollment. The study includes safety monitoring and adherence to protocols for dopaminergic drug withdrawal prior to tests. Total participation time covers these three dosing visits and evaluations within the study timeline.
CONDITIONS
Brief Title
Feasibility Study Assessing the Effect of Carbidopa/Levodopa Ratio on Orthostatic Hypotension in Multiple System Atrophy - Parkinsonian Type and Parkinson Disease.
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Signed informed consent form
- Age between 18 and 80 years
- Diagnosed with Multiple System Atrophy - Parkinsonian type or Parkinson Disease with orthostatic hypotension symptoms
- Currently receiving dopamine-replacement therapy combining levodopa with carbidopa or benserazide
You will not qualify if you...
- Unable to stand after overnight (at least 12 hours) withdrawal of immediate-release dopamine replacement therapy
- Known congestive heart failure, grades C and D, NYHA III and IV
- Dementia or major cognitive impairment associated with MSA-P or PD
- Mild cognitive impairment preventing informed consent
- Current participation in other clinical trials
- Pregnant, lactating, or planning to become pregnant
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Up to 5 weeks
Participants receive single oral doses of carbidopa/levodopa at three different ratios in random order and undergo orthostatic tests before and after each dose.
3 visits for dosing and testing
Trial Site Locations
Total: 2 locations
1
Centre Hospitalier Universitaire Vaudois (CHUV)
Lausanne, Canton of Vaud, Switzerland, 1005
Actively Recruiting
2
Centre Hospitalier Universitaire Vaudois
Lausanne, Canton of Vaud, Switzerland, 1012
Actively Recruiting
Research Team
J
Julien BALLY, Dr PD-MER
How is the study designed?
Study Type
INTERVENTIONAL
Masking
DOUBLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
TREATMENT
Number of Arms
3
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