An Open-Label Feasibility/Pilot Study With [123I]-IBZM SPECT (DOPA-SYN)
This study conducted to more fully evaluate the way that carbidopa/levodopa and entacapone may work in the brain. This research study uses [123I]-IBZM and dynamic SPECT imaging to determine the amount and the duration of dopamine release from specific regions in the brain after treatment with either the combination of carbidopa/levodopa or the combination of carbidopa/levodopa/entacapone.
Procedure: [123I]-IBZM imaging
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Assessment of Carbidopa/l-Dopa and Carbidopa/l Dopa/Entacapone on Synaptic Dopamine in Parkinson's Patients: An Open-Label Feasibility/Pilot Study With [123I]-IBZM SPECT (DOPA-SYN)|
- The primary outcome will be the reduction from baseline in IBZM striatal uptake during a 6-8 hour assessment period after treatment. [ Time Frame: 6-8hrs ] [ Designated as safety issue: No ]
- Secondary Measures include: Putamen and caudate uptake over time, UPDRS scores, and Pharmacokinetic analysis. [ Time Frame: 6-8hrs ] [ Designated as safety issue: No ]
|Study Start Date:||March 2004|
|Study Completion Date:||September 2004|
|Primary Completion Date:||September 2004 (Final data collection date for primary outcome measure)|
This is a pilot evaluation of dopaminergic function in PD using a bolus plus constant infusion protocol with [123I]-IBZM and SPECT to evaluate the potential for carbidopa/l-dopa alone or carbidopa/l-dopa/entacapone to produce displacement of striatal radioactivity for assessment of intrasynaptic dopamine. We will assess the feasibility of this paradigm for detecting l-dopa effects on the SPECT signal in subjects with PD with disease duration of greater than 4yrs and with a stable response to L-dopa. Each subject will undergo three [123I]-IBZM studies separated by 1-2 weeks. Subjects will be off medication for at least 12 h prior to study For each of the three scan days patients will receive a constant intravenous infusion of [123I]-IBZM over 4-5 hours to establish an equilibrium binding condition of the radiotracer at striatal D2/D3 receptors. Three baseline SPECT acquisitions will be obtained prior to medication dosing to establish a stable baseline. At approximately 5 h after the initiation of the infusion subjects will receive a single oral dose of either carbidopa/levodopa (37.5mg/150mg or 50mg/250mg), or carbidopa/levodopa/entacapone (either 37.5mg/150mg/200mg- STALEVO or 50/250mg/200mg).