Drugs for smoking cessation

Smoking is a risk factor for several diseases, including cancer, respiratory diseases and cardiovascular diseases. In Norway, about 21 % of the population smoke. There are two main types of smoking cessation programmes; counselling and drug assisted treatment. The two approaches can also be combined.  This project is focused drug assisted treatment only. There are two drugs on the Norwegian marked for use in smoking cessation; varenicline (Champix® or Chantix®) and bupropion (Zyban®). In addition there are several options for nicotine replacement therapy.

We have summarized the available research on the efficacy and safety of drugs for smoking cessation. We have considered comparisons between different drugs and between drugs and placebo. The review is intended to be used as part of the documentation basis for new national practice guidelines for smoking cessation in primary care.

We have summarized results from three high quality systematic reviews and 26 randomized controlled trials. Our endpoint was smoking cessation (measured as 7-day point prevalence or continuous abstinence) after 12, 24 and 52 weeks and side effects (serious adverse events, nausea, weight gain, insomnia, headache, abnormal dreams, fatigue, psychiatric symptoms, anxiety and dizziness).

Conclusion:
• Drugs for smoking cessation probably improve smoking cessation after 52 weeks compared with placebo.
• Varenicline will improve smoking cessation after 52 weeks compared to bupropion.
• We are uncertain whether there is any difference between different nicotine replacement therapies in terms of achieved smoking cessation.
• Combined use of two nicotine replacement products may improve smoking cessation than use of one product.
• Drugs seem to lead to more side effects than placebo.
• The documentation is too insufficient for us to determine if the drugs cause serious side effects.