Access to the latest research — for scientists and people living with PD alike — in PDF's new scientific journal.
Study: Parkinson's Drug May Slow Illness
- Dec 09 2004
A drug widely prescribed to treat symptoms of Parkinson's disease does not hasten the progression of the illness as some had feared, and it might even slow it down, a study suggests.
But the matter is far from settled. While patients in the study who used the drug showed less decline than those who didn't, brain scans suggested the drug might harm the crucial brain cells that die off in the disease.
It will take more work to establish the effects of levodopa on the course of Parkinson's disease, researchers conclude in Thursday's issue of the New England Journal of Medicine.
Levodopa has been prescribed for more than 30 years to treat Parkinson's symptoms like slow movement, stiffness and tremors. It's the "gold standard" for Parkinson's treatment, and eventually almost all patients come to use it.
But doctors have debated how early in the course of the disease to prescribe it, because of laboratory evidence that it might speed up the degeneration of the brain cells whose loss brings on Parkinson's.
The new work is the first hint that levodopa might actually be protective instead, said Dr. Stanley Fahn of Columbia University Medical Center, principal researcher of the federally funded study. That isn't proven yet, he stressed, but at least "it doesn't appear to be harmful."
The study split 361 patients into four groups, three of which were given levodopa while the fourth got a placebo. After 40 weeks of treatment, the drug was stopped for two weeks so that its effects would wear off, and researchers could see how severe the untreated disease was.
Results showed that patients who'd taken levodopa showed less worsening of their disease, suggesting levodopa had slowed progression. But the scientists also said it's possible that they didn't wait long enough for the drug's effects to wear off.
Researchers also did brain scans of 142 patients, to track the abundance of a particular protein used by the brain cells that are lost in Parkinson's. The scans showed that this supply declined more in the levodopa users than the other patients, suggesting the brain cells were dying off more quickly.
But the researchers said there were other possible explanations for the finding. Levodopa may just make the brain cells produce less of the measured protein, they noted.
Overall, the study presents "a mixed message," commented Dr. J. Timothy Greenamyre of the University of Pittsburgh School of Medicine, who didn't participate in the work. "Nobody knows exactly how to interpret it yet."
While the brain imaging results raise questions, the other part of the study suggests levodopa "doesn't hurt and it might be of benefit in slowing progression," he said.
A second study in the medical journal found that the Alzheimer's disease drug rivastigmine offers modest help in dementia associated with Parkinson's. It failed to help 80 percent of the treated Parkinson's patients, but Greenamyre said the result is still important because nothing else has been proven to ease dementia in that disease.
Source Date: Dec 09 2004
Source Publication: New York Times
View source URL