"Clinicians and patients often struggle with what is the right initial approach to treating Parkinson's disease," said University of Rochester Medical Center neurologist Kevin Biglan, M.D., M.P.H., the lead author of the paper and a member of the Parkinson's Study Group, an international network of researchers that oversaw the clinical trial.
"This study tells us that, over the long haul, patients on the different drugs end up at roughly the same place in terms of their level of disability and quality of life."
Parkinson's disease is a progressive neurological disorder that erodes a person's control over their movements and speech. Over time, Parkinson's patients may experience stiffness or rigidity of the arms and legs, slowness or lack of movement, and walking difficulties, in addition to tremors in their hands, arms, legs, jaw or face.
The study compared two drugs – levodopa and pramipexole – that are generally employed as the first line of treatment for Parkinson's disease. The two drugs use different mechanisms to counteract the decline in the production of dopamine in the brain that is a result of a progressive loss of cells that secrete the neurochemical. Levodopa is an amino acid that the body metabolizes into dopamine. Pramipexole is a dopamine agonist that binds with dopamine receptors on cells in the brain and mimics the chemical's molecular function.
While levodopa is considered to be better at addressing the motor control symptoms of the disease such as mobility issues and tremors, it is also associated with side effects such as dyskinesia (involuntary movements) and the effectiveness of the drug can diminish, or wear off, over time. Pramipexole is less effective with respect to motor control symptoms and more often causes sleepiness, but is less commonly associated with dyskinesias and wearing off. Pramipexole is often prescribed because clinicians believe it essentially extends the window in which the patient can benefit from levodopa by delaying the initial use of the drug – and its eventually wearing off. Most Parkinson's patients end up taking levodopa at some point regardless of their initial treatment because it is more effective at improving the symptoms of the disease.
The initial study followed 301 Parkinson's patients in 22 sites in the U.S. and Canada over a 2 year period. A sub-set (222) of the group was followed for an additional 4 years. Half the patients were randomly assigned to be initially treated with levodopa and the other half with pramipexole. After 6 years of follow-up, essentially all of the participants (90%) were taking levodopa. The researchers evaluated study participants using tools that measure disability (ability to perform daily activities), side effects, disease severity, and the patient's sleepiness.
The study confirmed that patients who are initially treated with levodopa are more likely to develop motor complications such as dyskinesias and wearing off even 6 years after treatment. However, it also shows that these complications did not have a significant impact on the quality of life or disability of the patients.
"Clinicians and patients still need to establish their treatment priorities to understand unique circumstances that argue in favor of one drug vs. the other," said Biglan. "However, this study should assuage any concerns that the treatment decisions that are made early in the disease will have long-term implications, which does not appear to be the case."
Mark Michaud | EurekAlert!
Further reports about: > Parkinson's treatments > Tremors > body metabolizes > chemical's molecular function > dopamine > dyskinesia > involuntary movements > lack of movement > levodopa > pramipexole > progressive neurological disorder > quality of life > rigidity of the arms and legs > walking difficulties
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences