Key findings

Strength of Evidence

Each key finding has been rated according the strength of evidence supporting it.
Multiple well-designed, randomized clinical trials yielded a consistent pattern of findings.
Some evidence from randomized clinical trials but the scientific support was not optimal.
Limited evidence indicative of a possible effect but not sufficient to support a recommendation.

1. The main adverse effect of nicotine is addiction, which sustains tobacco use. Because most smokers are nicotine-dependent, they continue to expose themselves to toxins from tobacco. Tobacco, not nicotine, is responsible for most of the adverse health effects.
   commentary and supporting evidence


2. Nicotine is not a significant risk factor for cardiovascular events. The benefit of nicotine replacement therapy outweighs the risks of nicotine medication, even in smokers with cardiovascular disease.
   commentary and supporting evidence


3. Nicotine per se is not a substantial cause of cancer. Any cancer-related risks during short-term nicotine therapy to aid smoking cessation are insignificant compared to the risks of smoking.
   commentary and supporting evidence


4. Nicotine is a potential foetal teratogen based on studies in animals and might contribute to sudden infant death syndrome and neurobehavioral deficits in the offspring. However these effects are dose-related in animals, and NRT products have not been demonstrated to be teratogenic in humans.
   commentary and supporting evidence


5. While nicotine replacement therapy during pregnancy is potentially hazardous, it is likely that nicotine therapy is less hazardous than cigarette smoking, which exposes both the mother and foetus to both nicotine and a myriad of other toxins.
   commentary and supporting evidence


6. Bupropion use during pregnancy has been inadequately studied, making it difficult to compare risks vs. benefits of use in pregnant smokers. No data are available on varenicline use during pregnancy.
   commentary and supporting evidence


7. Nicotine replacement products have low abuse liability, especially compared to tobacco products. Long-term use of nicotine medications, although relatively rare, is likely to be less risky than smoking cigarettes and therefore an overall health benefit if the individual is no longer smoking.
   commentary and supporting evidence


8. Bupropion is generally well tolerated by smokers.
   commentary and supporting evidence


9. Bupropion appears not to have significant abuse liability.
   commentary and supporting evidence


10. Nortriptyline, moclobemide and clonidine have been found in smoking cessation trials in healthy smokers to be safe in doses approved for the treatment of depression/hypertension.
    commentary and supporting evidence


11. The benefits of bupropion to aid smoking cessation outweigh the risks of bupropion in most smokers.  Data on the safety of bupropion in patients with cardiovascular disease and during pregnancy are not yet available.
    commentary and supporting evidence


12. The use of medications, including nicotine replacement therapy, bupropion and varenicline, is safe even when used by individuals who are still smoking cigarettes. Concomitant use of nicotine replacement therapy and bupropion or nortriptyline is generally well-tolerated.
    commentary and supporting evidence


13. "Reduced risk" cigarettes including low tar cigarettes and novel tobacco products that deliver nicotine with minimal combustion of tobacco are promoted, implicitly or explicitly, to reduce the harm from smoking. None of these products have been determined to reduce the risk of cigarette smoking or to aid smoking cessation. Nicotine replacement therapy, bupropion, varenicline and other medications to aid smoking cessation are most likely safer than any "reduced risk" cigarette.
    commentary and supporting evidence


14. Smokeless tobacco, such as snuff or chewing tobacco, has been suggested as a potential aid to harm reduction or smoking cessation. Smokeless tobacco products contain nitrosamines and other carcinogens, and are known to produce oral and pancreatic cancer (IARC, 2007). Smokeless tobacco products are addicting. At this time smokeless tobacco is not recommended as an aid to smoking cessation.
    commentary and supporting evidence


15. Long-term pharmacotherapy has been suggested as a potential aid to harm reduction or smoking cessation. Nicotine, bupropion and varenicline taken over long periods are likely to be much safer than cigarette smoking. However the efficacy of long-term medication use to reduce harm or aid cessation has not yet been demonstrated.
    commentary and supporting evidence


16. There is little reason to believe that nicotine replacement therapy, bupropion or varenicline pose a significantly greater risk to adolescents who smoke >10 cigarettes per day compared to adults who smoke >10 cigarettes per day.
    commentary and supporting evidence