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High and Low Dose Carbidopa Treatment of Parkinson's Disease

This study has been completed.
Sponsor:
Information provided by:
Oregon Health and Science University
ClinicalTrials.gov Identifier:
NCT01399905
First received: July 21, 2011
Last updated: NA
Last verified: July 2011
History: No changes posted
  Purpose

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.


Condition Intervention Phase
Parkinson's Disease
Drug: carbidopa
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Randomized Controlled Trial of Four Week Outpatient Treatment of Parkinson's Disease Comparing High and Low Dose Carbidopa.

Resource links provided by NLM:


Further study details as provided by Oregon Health and Science University:

Primary Outcome Measures:
  • AUC of tapping speed [ Time Frame: Performed every 30 minutes from 8 AM to 2 PM ] [ Designated as safety issue: No ]
    Tapping speed is an index of bradykinesia and is used as a response to levodopa infusion.


Secondary Outcome Measures:
  • AUC of levodopa plaasma concentrations [ Time Frame: Measured every 30 minutes from 9 AM, the beginning of the infusion until 2 PM ] [ Designated as safety issue: No ]

Enrollment: 12
Study Start Date: March 2009
Study Completion Date: May 2011
Primary Completion Date: April 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: High carbidopa followed by low carbidopa
450 mg of carbidopa per day for four weeks followed by 75 mg of carbidopa per day for four weeks
Drug: carbidopa
75 mg of carbidopa per day versus 450 mg of carbidopa per day
Experimental: Low carbidopa followed by high carbidopa
75 mg of carbidopa per day for four weeks followed by 450 mg of carbidopa per day
Drug: carbidopa
75 mg of carbidopa per day versus 450 mg of carbidopa per day

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   35 Years to 85 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Idiopathic Parkinson's disease
  • Treatment with carbidopa/levodopa
  • Motor fluctuations

Exclusion Criteria:

  • Dementia
  • Hallucinations
  • Age greater than 85
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01399905

Locations
United States, Oregon
Oregon Health & Science University
Portland, Oregon, United States, 97239
Sponsors and Collaborators
Oregon Health and Science University
Investigators
Principal Investigator: John G Nutt, MD Oregon Health and Science University
  More Information

No publications provided

Responsible Party: John Nutt, MD, Oregon Health & Science University
ClinicalTrials.gov Identifier: NCT01399905     History of Changes
Other Study ID Numbers: Aldred4133
Study First Received: July 21, 2011
Last Updated: July 21, 2011
Health Authority: United States: Food and Drug Administration

Keywords provided by Oregon Health and Science University:
Parkinson's disease
Levodopa
Carbidopa
Blood brain barrier

Additional relevant MeSH terms:
Parkinson Disease
Basal Ganglia Diseases
Brain Diseases
Central Nervous System Diseases
Movement Disorders
Nervous System Diseases
Neurodegenerative Diseases
Parkinsonian Disorders
Carbidopa
Anti-Dyskinesia Agents
Antiparkinson Agents
Central Nervous System Agents
Dopamine Agents
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Pharmacologic Actions
Physiological Effects of Drugs
Therapeutic Uses

ClinicalTrials.gov processed this record on November 20, 2014