High and Low Dose Carbidopa Treatment of Parkinson's Disease
Public ClinicalTrials.gov record NCT01399905. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A Randomized Controlled Trial of Four Week Outpatient Treatment of Parkinson's Disease Comparing High and Low Dose Carbidopa.
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Hypothesis: We hypothesize that carbidopa in daily doses of 450mg will enter the central nervous system and partially inhibit AAAD, thereby reducing the decarboxylation of exogenous levodopa to dopamine, and thereby blunt the therapeutic effects of levodopa in PD subjects. The purpose of this study is to see how low dose vs. high dose of the study drug, carbidopa effect movement in subjects with Parkinson's disease. The low dose of the study drug is 75 mg and the high dose is 450mg. Subjects will be recruited from the investigators clinic when they are seen for treatment for Parkinson's disease. Subjects will also be recruited through flyers hung at OHSU and at the VA. Subjects will take part in 2 screening visits one week apart to determine eligibility. Subjects will be randomly chosen to start either high or low dose carbidopa and take it for 4 weeks. Subjects will be called 2, 4, and 6 or 7 days after this visit to ask how they are doing after starting this dose of study drug. We will leave them a message if we cannot reach them. If there are any problems, we will schedule them to come to the clinic within the next 2 days. Subjects will have an outpatient visit 2 weeks after screening and a hospital admission 2 weeks after that. At the hospital, subjects will stay for 3 days. They will have blood drawn and their Parkinson's disease assessed by a finger tapping exercise, timing their walking, and looking at their uncontrolled movements. The subject will then receive the opposite dose of carbidopa for 4 weeks. Subjects will be called 2, 4, and 6 or 7 days after this visit to ask how they are doing after starting this dose of study drug. We will leave them a message if we cannot reach them. If there are any problems, we will schedule them to come to the clinic within the next 2 days. The outpatient visit and hospital admission will repeat again. At the end of the second hospital admission, treatment on the study is over and subjects will go back to their original Parkinson's disease medications. The study will end with a follow up phone call or clinic visit 2 - 4 weeks after the final hospital admission. Subjects will fill out a daily diary that asks about their movement throughout the day for 3 days before they come to the Oregon Clinical and Translational Research Institute. Carbidopa is used for the treatment of Parkinson's disease with levodopa. This protocol is using a high dose of 450mg of carbidopa. This study is also using IV levodopa, which is a different route than is normally given. Finger tapping rates will be compared between high and low dose study drug use to see if one group has slower rates than the other.
Study identification
- NCT ID
- NCT01399905
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 14 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 35 Years to 85 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Feb 28, 2009
- Primary completion
- Mar 31, 2011
- Completion
- Apr 30, 2011
- Last update posted
- Jan 8, 2020
2009 – 2011
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Oregon Health & Science University | Portland | Oregon | 97239 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT01399905, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Jan 8, 2020 · Synced Sep 8, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT01399905 live on ClinicalTrials.gov.