Continuous L-dopa delivery useful for Parkinson’s

Giving the anti-  Parkinson’s drug levodopa continuously through a naso-gastric tube is better than the pill form of the drug at reducing the movement problems seen with the disease, according to a report in the Archives of Neurology.

With the continuous approach, a narrow tube is inserted through the nose and then advanced into the intestine under x-ray guidance. Once in position, a small amount of liquid levodopa is pumped into the intestine on a continuous basis.

This infusion method of delivering levodopa is thought to work better than simply taking a pill because drug levels in the body don’t fluctuate as much.

With a pill, the periodic rise and drop in drug levels can actually have a damaging effect on nerve cells and lead to permanent movement problems.

“Levodopa-induced (movement problems) are the major reason why patients have surgery for Parkinson’s,” said Dr. C. Warren Olanow, from Mount Sinai School of Medicine in New York. “What we’re trying to do is figure out how to prevent these adverse events so patients won’t need surgery.”

In the present study, Olanow’s group switched six patients with advanced   Parkinson’s disease from levodopa pills to naso-gastric infusions of the drug and then evaluated the effect on movement.

Changing to the infusions significantly reduced the movement problems seen in the patients and improved their ability to perform routine activities of daily living.

Unfortunately, the problem with infusions is that they’re inconvenient, Olanow noted. “What we want to do is figure out why infusion is better than (pills)” and maybe then a way can be found to give levodopa that better suits the body’s physiology.

He theorizes that giving levodopa pills in combination with drugs called COMT inhibitors may reproduce the benefits seen with infusion.

“We’ve shown that when monkeys take levodopa with the COMT inhibitor they have less (movement problems) than if they take levodopa alone,” Olanow said. He and his associates are now in the planning stages of a large trial to test this strategy in humans.

SOURCE: Archives of Neurology, June 2005.

Provided by ArmMed Media
Revision date: July 3, 2011
Last revised: by Janet A. Staessen, MD, PhD