L-Dopa Still First Choice for Parkinson's
Jan. 9, 2002 -- The king is dead -- not! Reports of L-dopa's demise were exaggerated, the American Academy of Neurology (AAN) now says.
For 30 years, L-dopa has been the first-line treatment for Parkinson's disease. That reign appeared to end in June 2001 when a special issue of the AAN's official journal said that newer Parkinson's drugs should be used first. It advised doctors to save L-dopa for when the new drugs stopped working. These recommendations -- in a special volume subtitled "Treatment Guidelines" -- were the work of a team of three renowned Parkinson's specialists aided by a panel of their peers
Now a new panel of experts -- with the official blessing of the AAN -- says that L-dopa is still the best first choice for many patients. These guidelines tell doctors that either L-dopa or the new drugs can be used for first-line treatment of Parkinson's symptoms.
"These guidelines were in the process of approval when the paid supplement to the Journal of Neurology, written by three experts, put out [advice] on how to treat Parkinson's disease," AAN president Stanley Fahn, MD, tells WebMD. "It was according to them. It was not official. It did have the subtitle 'Guidelines,' which was an oversight by the editor of the journal. Guidelines can only be made by an official committee of the AAN." Fahn did not participate in writing the new guidelines.
The special supplement was paid for by pharmaceutical giant GlaxoSmithKline, which makes one of the new drugs. A spokeswoman for the AAN said this means it was much like a paid advertisement -- an allegation that irks the experts who wrote it. One of these authors is William C. Koller, MD, PhD, director of the Parkinson's Disease Center at the University of Miami, Coral Gables, Fla.
"We think that is a terrible thing to say," Koller tells WebMD. " It was strictly our work. The company had nothing to do with the document. We convened a group of specialists. And we are three guys who do Parkinson's research and who are well respected. The authors of the new guidelines are just a group of guys who do Parkinson's research, too. Their expertise is no different than our expertise. I don't see the big difference just because they went through the AAN committee."
The difference between the two sets of recommendations boils down to one sad fact: there is no cure for Parkinson's disease. Available treatments slow, but do not stop, its relentless progress.
Parkinson's happens when certain brain cells slowly die off. These are the cells that produce the chemical messenger called dopamine. Without dopamine, the part of the brain that controls movement stops working.
L-dopa turns into dopamine in the brain and, for a while, restores function. It often works too well, however, and instead of too little movement, patients have too much unwanted movement. This is called dyskinesia.
The new drugs, called dopamine agonists, work differently. They mimic the action of dopamine in the brain. These drugs are much less likely to cause dyskinesia, but they have their own problems. Side effects can include hallucinations and sleep attacks. They also don't work quite as well as L-dopa in controlling some major Parkinson's symptoms.
Fahn, director of the movement disorder division at New York's Neurological Institute, says he usually starts older patients with L-dopa. He starts younger patients with the newer drugs because prolonged L-dopa treatment is more likely to lead to dyskinesia. Koller uses much the same strategy.