New drug helps patients stop smoking, researchers say
Last Updated: Thursday, July 6, 2006 | 6:56 PM ET
CBC News
Related
Internal Links
A new stop-smoking drug appears to work better than drugs currently on the market, but it's likely that no pill will ever be 100 per cent effective, scientists say.
Three studies published this week suggest that varenicline, a new smoking cessation drug developed by Pfizer, is more effective in the short term than Zyban, manufactured by rival GlaxoSmithKline.
However, an editorial accompanying the studies cautions that varenicline is no miracle drug and most people who took it during the studies did not stop smoking.
Pfizer funded all three of the studies, published in Wednesday's issue of the Journal of the American Medical Association.
Varenicline stimulates nicotine receptors enough to release dopamine in the brain, reducing the craving for cigarettes and the withdrawal effects, but not so much that it is itself addictive.
Third type of anti-smoking aid
Many pharmaceutical stop-smoking aids, such as the patch, contain nicotine and gradually reduce the dose over time to make withdrawal from cigarettes more gradual.
Another drug, bupropion, is an antidepressant that reduces the severity of nicotine cravings and withdrawal symptoms. It is marketed as Zyban for this purpose and as Wellbutrin as an antidepressant.
Two of the studies were conducted in the U.S. and compared the effectiveness of varenicline in helping patients quit smoking in comparison with bupropion and a placebo.
Patients in these trials were treated for 12 weeks and their smoking was monitored for a year. During the last four weeks of their treatment, about 44 per cent of patients taking varenicline were still abstaining from smoking, compared to 30 per cent of those taking bupropion and 18 per cent taking the placebo.
After a year, about 22 per cent of those taking varenicline still had not resumed smoking, compared to eight per cent of those taking the placebo and 16 per cent of those taking bupropion. The authors said varenicline was not significantly more effective than bupropion after one year.
The third study was conducted to determine whether taking varenicline over a longer period of time could prevent people who had stopped smoking from starting again.
Most still smoking a year later
Patients were given varenicline for 12 weeks and about 64 per cent of them didn't smoke during the last week. Some of those who stopped smoking were then treated for another 12 weeks, with either varenicline or a placebo.
At the end of those 12 weeks, about 70 per cent of those taking varenicline has not smoked, compared to about 50 per cent of those taking the placebo. After a year, about 44 per cent of those taking the drug had not smoked, compared to 37 per cent of those taking the sugar pill.
The authors point out that, as in all studies on smoking cessation lasting a year or more, more than 50 per cent of people who began treatment started smoking again.
"Cleary, quitting smoking, even with pharmacological and behavioural assistance, is extremely difficult," write three researchers at the University of Tennessee Health Science Center in Memphis, in an editorial accompanying the studies. "Patients currently cannot and probably never will simply be able to 'take a pill' that will make them stop smoking."
Share Tools
Top News Headlines
- Montreal protesters march in peaceful defiance
- The clanging of pots and pans sounded throughout Montreal's downtown core Saturday night and into early Sunday morning, as thousands of protesters marched on in peaceful — but loud — defiance of Bill 78. more »
- Quebec tornadoes cause millions in damage
- Environment Canada confirms that two tornadoes — one of which was classed as a moderate F-1 packing winds of up to 150 km/h — touched down near Montreal Friday night, causing millions of dollars in damage. more »
- Teen struck by lightning in Ottawa dies
- The victim of a Friday lightning strike during a storm in east Ottawa has died, CBC News has learned. more »
- Missing Winnipeg children found in Mexico
- Two Winnipeg children reported missing and possibly in Mexico have been found alive, according to unofficial reports from an agency that works to find missing people. more »
Latest Health News Headlines
- Alcohol addiction team wants higher energy drink prices
- Mixing alcohol with caffeine-rich energy beverages is a trend that is continuing to rise in Canada, despite repeated warnings that the combination is unsafe, a new report warns. more »
- How curry spice helps the immune system kill bacteria
- A spice used in curry dishes helps to prevent infection and now scientists think they've got a lead on how. more »
- Yellowknife toddlers catching hand, foot and mouth virus
- An outbreak of hand, foot and mouth disease in Yellowknife is causing many toddlers and their parents some major discomfort. more »
- Super microscope installed at University of Victoria
- What's heralded as the world's biggest microscope has arrived at the Unversity of Victoria, marking the culmination of a 10-year effort by one of the school's professors. more »
FEATURED HEALTH
- Teen struck by lightning in Ottawa dies
- Missing Winnipeg children found in Mexico
- Quebec tornadoes cause millions in damage
- Montreal protesters march in peaceful defiance
- Woman's remains found in hockey bag on Cape Breton river
- Pope's butler arrested in Vatican leaks scandal
- Everest team unable to bring down Toronto woman's body
- WWE apologizes to Brazil over Canadian's flag stomp
- What a Greek euro exit could mean for Canada

