After Parkinson's disease patients use the drug levodopa or L-dopa for several years as a treatment for restoring the cellular communication that controls muscle movement by replacing lost dopamine, they begin to experience motor complications that include a shortened response to each dose of L-dopa.
"As time goes on and the disease progresses, the off periods, that is, time during which the medicine is not working at its best, come more frequently as on periods, or times during which patients experience their best response to the drug, last for shorter periods of time," explained Jay S. Schneider, PhD, who heads the Parkinson's Disease Research Unit at Thomas Jefferson University Hospital.
Parkinson's disease gradually destroys brain cells that produce dopamine. As dopamine levels drop, symptoms increase: tremors in the arms, legs and face; periodically stiff or frozen limbs; slow movement, particularly a shuffling gait; and impaired balance and coordination.
Dr. Schneider, Professor of Pathology, Anatomy and Cell Biology and Neurology at Jefferson Medical College of Thomas Jefferson University, and movement disorder specialists Tsao-Wei Liang, M.D., Assistant Professor of Neurology, Jefferson, and Daniel Erik Kremens, M.D., J.D., Assistant Professor of Neurology, Jefferson, are spearheading a new clinical trial to test a new anti-Parkinson's drug in an attempt to decrease such off-time experiences and extend L-dopa's effectiveness.
The study will evaluate whether a drug, E2007, can significantly lengthen the time that a patient's L-dopa medication is effective, reducing both the amount of off time during the day, as well as other unwanted side effects of L-dopa treatment. E2007 is non-dopaminergic drug that acts on a subclass of receptors called the AMPA receptors, which mediate fast synaptic transmission in the central nervous system.