The current multicentre study evaluated a “reduce to quit approach” with varenicline for six months. Participants were adults, smoked an average of 10 or more cigarettes per day with no continuous abstinence period longer than 3 months in the past year, had an exhaled carbon monoxide level higher than 10 ppm, and were not willing or able to quit smoking within the next month but were willing to reduce their smoking and make a quit attempt within the next 3 months.
The study consisted of a 24-week treatment period (12 week reduction phase and 12 week abstinence phase in which participants were randomised to varenicline [n=760]or placebo [n=750]), followed by a 28-week non-treatment follow-up phase. The primary efficacy end point was the carbon monoxide–confirmed continuous abstinence rate (CAR) during the last 10 weeks of treatment (ie, weeks 15-24) and was 32.1% for the varenicline group vs 6.9% for the placebo group.
Adverse events were more frequently reported in the varenicline group than in the placebo group (82.3% vs 72.5% in the placebo group) but this did not translate into a difference in permanent treatment discontinuation between the two groups.
National smoking cessation guidance recommends that smokers set a date to quit smoking and quit abruptly. Since most patients are unwilling to commit to a quit date, the strategy of reducing the number of cigarettes smoked per day with the eventual goal of quitting could be a useful therapeutic option for this population of smokers, although the prevalence of smokers in the general population who meet the definition of smokers enrolled in this study remains unknown.
Varenicline (Champix™) is licensed for a more gradual approach to quitting smoking in patients who are not able or willing to quit abruptly. NICE (TA 123; July 2007) recommends varenicline as an option for smokers who have expressed a desire to quit smoking as part of a programme of behavioural support