Cough medicine fights dyskinesias in Parkinson's

Nov 07, 2007

A cough suppressant and a drug tested as a schizophrenia therapy curb the involuntary movements that are disabling side effects of taking the Parkinson's disease medication levodopa, Portland scientists have found.

Dextromethorphan, used in such cold and flu medications as Robitussin, Sucrets, Triaminic and Vicks, suppresses dyskinesias in rats, researchers at Oregon Health & Science University and the Portland Veterans Affairs Medical Center found. Dyskinesias are the spastic or repetitive motions that result from taking levodopa, or L-dopa, over long periods.

The researchers also found that BMY-14802, a drug previously tested in people with schizophrenia and found to be safe – although not effective in treating schizophrenia symptoms – suppressed dyskinesias in rats more effectively than dextromethorphan did, suggesting that BMY-14802 might work to block dyskinesias in people with Parkinson's.

"These results were unexpected, but very exciting," said the study's lead author, Melanie A. Paquette, Ph.D., postdoctoral fellow in the Department of Behavioral Neuroscience, OHSU School of Medicine, and the PVAMC. "We have filed a patent for the use of BMY-14802 for dyskinesias and we hope to get funding to begin human trials very soon."

The study, titled "Differential effects of NMDA antagonists and sigma ligands on L-dopa-induced behavior in the hemiparkinson rat," is being presented during a poster session today at Neuroscience 2007, the 37th annual Society for Neuroscience conference in San Diego.

The results also affirm the value of the rat model for dyskinesias that Paquette's team used in the study. Previous studies by other researchers have shown the drug amantadine already is effective in treating dyskinesias in both humans and rats, and dextromethorphan's effectiveness against the condition in rats provides more data supporting the use of the model.

"Basically, these two drugs work to block dyskinesias in both humans and rats, and that means the rats are a good model to screen potential drug treatments for humans with dyskinesias," Paquette said.

But BMY-14802, which is an antagonist at sigma-1 receptor sites in the brain, "worked much better than dextromethorphan," an antagonist at N-methyl-D-aspartate (NMDA) receptors.

"There's something special about BMY-14802," Paquette explained. "The effect on dyskinesias is really striking and I've repeated it several times, so it's a reliable finding. It's a very exciting result."

Source: Oregon Health & Science University

Explore further: Presence of peers ups health workers' hand hygiene

add to favorites email to friend print save as pdf

Related Stories

Team improves solar-cell efficiency

9 hours ago

New light has been shed on solar power generation using devices made with polymers, thanks to a collaboration between scientists in the University of Chicago's chemistry department, the Institute for Molecular ...

Calif. teachers fund to boost clean energy bets

9 hours ago

The California State Teachers' Retirement System says it plans to increase its investments in clean energy and technology to $3.7 billion, from $1.4 billion, over the next five years.

Alibaba surges in Wall Street debut

9 hours ago

A buying frenzy sent Alibaba shares sharply higher Friday as the Chinese online giant made its historic Wall Street trading debut.

Dwindling wind may tip predator-prey balance

9 hours ago

Bent and tossed by the wind, a field of soybean plants presents a challenge for an Asian lady beetle on the hunt for aphids. But what if the air—and the soybeans—were still?

Recommended for you

Presence of peers ups health workers' hand hygiene

9 hours ago

(HealthDay)—The presence of other health care workers improves hand hygiene adherence, according to a study published in the October issue of Infection Control and Hospital Epidemiology.

Sierra Leone streets deserted as shutdown begins

17 hours ago

Sierra Leone's normally chaotic capital resembled a ghost town on Friday as residents were confined to their homes for the start of a three-day lockdown aimed at halting the deadly Ebola epidemic.

Sierra Leone launches controversial Ebola shutdown

18 hours ago

Sierra Leone on Friday launched a controversial three-day shutdown to contain the deadly spread of the Ebola virus, as the UN Security Council declared the deadly outbreak a threat to world peace.

User comments : 0