|myCNN | Video | Audio | Headline News Brief | Free E-mail | Feedback||
Nicotine therapy promising for neurological disorders
(WebMD) -- Just when nicotine's status as the reviled addictive ingredient in tobacco seemed secure, it may turn out to have a saving grace after all.
New research, presented Monday at the annual meeting of the American Association for the Advancement of Science in Washington, D.C., adds to the growing evidence that nicotine may help to improve both motor and mental function in patients suffering from Alzheimer's and Parkinson's diseases, attention deficit hyperactivity disorder and Tourette's syndrome.
The substance may do this by regulating acetylcholine and dopamine -- two chemicals that play crucial roles in a range of neurological and behavioral disorders. For example, Alzheimer's patients appear to lack sufficient amounts of acetylcholine and Parkinson's patients are short on dopamine.
Research data showing that smokers have a lower risk than non-smokers of developing Parkinson's and certain other diseases began sparking scientists' interest in nicotine about a decade ago. In recent years, several pharmaceutical companies -- as well as a couple of tobacco companies -- began seriously to study nicotine as a therapeutic drug.
But scientists are very careful to emphasize that this field of research is in no way intended to promote smoking. The health hazards that smoking poses, they say, would overshadow any potential benefit of nicotine. "No one would ever argue that somebody should take up smoking to prevent Parkinson's," said Dr. Paul Newhouse, director of the Clinical Neuroscience Research Unit at the University of Vermont College of Medicine. "That would be silly."
Instead of cigarettes, researchers used the over-the-counter nicotine gum and patches meant to help smokers kick the habit. In a pilot study to be published within the next few months, Newhouse gave 15 patients with Parkinson's disease varying doses of nicotine using these patches. (Researchers also gave the patients intravenous doses separately for comparison). Typical symptoms of Parkinson's disease include tremors and difficulty moving or maintaining posture, and many patients go on to develop dementia.
The degree of motor and cognitive improvement ranged from "very small" to "dramatic," varying from patient to patient, Newhouse said at a news briefing. Some patients were so pleased with the results that they continued to use the patches on their own, long after the study was over.
While the results have been encouraging, Newhouse said it is still too early to begin recommending nicotine treatment for Parkinson's disease. "We don't know what its safety profile would be over the long haul for this kind of a patient," he said. "I think it would be a bit rash to suggest that people should go out and buy these patches without significantly more (research)."
The researchers acknowledged that to date most of the studies on nicotine's possible beneficial uses as a drug have been small. But a larger double-blind trial involving 70 children with Tourette's syndrome may add credibility. Conducted by Paul Sanberg, Ph.D., professor and chair of neuroscience at the University of South Florida, researchers treated children with nicotine patches in addition to reduced doses of the more-standard treatment Haldol, an anti-psychotic drug also used to treat schizophrenia.
Sanberg said the findings -- which have not yet been published -- corroborate earlier studies in which nicotine subdued the muscular and vocal tics caused by the disorder.
Despite results that are beginning to offer hope to the hundreds of thousands of Americans with neurological disorders, nicotine therapy is far from perfect.
"It's not a very pleasant drug to take, " Newhouse said. "It produces lots of side effects."
These include nausea, muscle cramps and an increased heart rate, caused by nicotine acting on the 1,000 or more nicotine receptors located throughout the body, said Phyllis Pugh, Ph.D., a nicotine researcher at the Medical College of Ohio. The trick, she said, is to bypass these receptors while targeting the five or six major nicotinic receptors in the brain, which may be regulating the specific disorder being treated.
That goal is why many researchers are turning to nicotine-like compounds rather than nicotine itself, said Seth Moskowitz, a spokesman for the R.J. Reynolds Tobacco Company, which spun off a subsidiary called Targacept three years ago to focus on developing medications that can mimic nicotine's beneficial effects.
Separately, Newhouse has been working on one such nicotine mimic, called ABT-418, which has shown some promise in Alzheimer's patients. Sanberg said mecamylamine, an older medication originally approved to treat high blood pressure, may also prove effective for Tourette's syndrome because it has been found to act on nicotine receptors.
"Nicotine is not going to turn out to be a drug that's very useful in the long run," said Newhouse. Nicotine will only be used until researchers develop effective substitutes.
© 2000 Healtheon/WebMD. All rights reserved.
RELATEDS AT :
American Association for the Advancement of Science
|Back to the top||
© 2001 Cable News Network. All Rights Reserved.|
Terms under which this service is provided to you.
Read our privacy guidelines.