New Approach May Help Smokers Quit
March 20, 2000 (Los Angeles) -- A drug now used to treat a skin condition called psoriasis might also help people quit smoking. Uvadex (methoxsalen) interferes with the body's metabolism of nicotine. Smokers taking it typically need fewer cigarettes to keep the nicotine in their bloodstream at the level they have become accustomed to, researchers say.
Edward M. Sellers, MD, PhD, tells WebMD that smokers who took Uvadex as part of a small study "were unable to maintain their usual smoking behaviors," although researchers repeatedly reminded them that they were supposed to continue smoking as usual. Sellers is at the Centre for Addiction and Mental Health, University of Toronto. The study was funded in part by Nicogen, a company that manufactures antismoking aids.
If this research, which was reported Thursday at the annual meeting of the American Society for Clinical Pharmacology and Therapeutics, holds up in larger studies, Uvadex could be an important new tool for smokers who are trying to quit -- and for the doctors who are trying to help them.
"Tobacco dependence is the No. 1 public health problem in the world, and we don't have many choices in ways to help people stop," Sellers says. "Only about 10% of people who stop smoking using current aids are still off smoking after a year's time."
Richard D. Hurt, MD, who heads the Mayo Clinic's Nicotine Dependence Center, says that the use of Uvadex "is a really new and important area to explore." Hurt, who reviewed the study for WebMD, says that the Toronto group is breaking new ground by exploring nicotine metabolism.
Sellers and his colleagues gave Uvadex to 11 smokers, who consumed an average of 23 cigarettes per day. After three days, the participants' plasma nicotine levels were up, though their exposure to smoke was down.
Further, the treatment reduced levels of a cancer-causing compound called NNK that is produced from tobacco smoke.
Sellers says that smoking has a strong behavioral component, and that reducing the number of cigarettes smokers need to attain the same nicotine level is likely to help them quit. "One would envision a stepped-care approach" that gradually lowers nicotine levels as smokers discover they are able to smoke fewer and fewer cigarettes per day, he says.
Hurt hopes that Uvadex will make current antismoking treatments more effective. "Inhibition of nicotine metabolism could improve traditional therapies such as nicotine gum or patches," Hurt says. "The cigarette is the most efficient way to deliver nicotine, and so far it cannot be matched by other nicotine delivery systems. The result is that we are underdosing patients [with patches or gum] because we cannot reach the blood nicotine levels associated with smoking."
Reducing NNK is helpful, but "this isn't going to make smoking safe," Hurt says. "Tobacco smoke has about 40 carcinogens, and Uvadex reduces the level of only one of them."