Experimental Gel May Help Those With Advanced Parkinson's
WEDNESDAY, April 18 -- A gel form of two common Parkinson's drugs delivered via a feeding tube-like device may help people with advanced disease reduce medication side effects and possibly avoid brain surgery.
That's the report from researchers who found the experimental levodopa-carbidopa intestinal gel works better than a standard pill regimen in reducing "off" time in people with advanced Parkinson's disease.
About 1 million people in the United States are living with Parkinson's disease, a progressive movement disorder marked by tremor, slowness and/or rigidity. The disease slowly destroys the nerve cells in the brain that produce the chemical dopamine, which controls muscle movement.
Treatment with oral levodopa-carbidopa -- brand names include Sinemet, Sinemet CR and Parcopa -- helps replace dopamine levels, but higher doses and long-term use of the oral drugs can cause troublesome side effects, including spontaneous and involuntary movements (dyskinesias) or "off" times.
The new gel is infused through a portable pump connected to a gastric tube that feeds the small intestine. "Pills have a shorter half-life, but delivering the medication via gel allows for more continuous delivery and repairs the brain levels in a more normal way," said study author Dr. C. Warren Olanow, a professor of neurology and neuroscience at the Mount Sinai School of Medicine, in New York City. As a result, "you have less 'off' time and less dyskinesia," he added.
While not a cure for the disease, the method is an important step forward, Olanow said. "It's a proof of concept that when you deliver the medication continuously, you get a better response without worsening dyskinesia," he noted.
And the new gel "may also have applications in early Parkinson's disease to help people avoid the side effects that come from long-term continuous use of these medications," he added.
The study was released April 17 and will be presented next week at the American Academy of Neurology's annual meeting in New Orleans.
In his study, 71 participants received either the continuous infusion of the gel and inactive placebo pills or an inactive gel and pills that contained levodopa-carbidopa. When the three-month study began, the average participant had Parkinson's disease for about 11 years and experienced 6.6 hours of "off" time every day.
Those who received the gel reduced their "off" time by about nearly two extra hours per day and their "on" time -- or time spent without movements -- increased by an average of two hours per day, compared to those who took levodopa and carbidopa in pill form, the researchers reported. The most common side effects with the gel were related to complications inserting the device, abdominal pain, pain during the procedure and nausea.
The plan is submit the current data to the U.S. Food and Drug Administration for approval. The study was supported by Abbott Laboratories, the company developing the new intestinal gel.
"It sounds like a good option for people with advanced Parkinson's disease," said Dr. Roy Alcalay, an assistant professor of neurology at Columbia University Medical Center in New York City, and an adviser for the Parkinson's Disease Foundation. "The indications are similar to those of the brain surgery [known as deep brain stimulation], and may be good for people who do not want the surgery or those who still have a lot of symptoms and medication side effects after surgery," he said.
"The drug seems to work well, but the major concern with the drug is the problems around its administration, which include an abdominal procedure done by a gastroenterologist," he added.
Findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.
Learn more about Parkinson's disease at the Parkinson's Disease Foundation .
Posted: April 2012