Varenicline: a pharmacoeconomic review of its use as an aid to smoking cessation.

Varenicline (Chantix, Champix) is an orally administered alpha4beta2 nicotinic acetylcholine receptor partial agonist that is indicated as an aid to smoking cessation. Well designed clinical trials indicate that varenicline is an effective aid to smoking cessation. During the last 4 weeks of treatment, carbon monoxide-confirmed continuous abstinence rates were generally significantly higher with varenicline than with placebo, bupropion sustained release (SR) or nicotine replacement therapy. Varenicline also reduced cravings, the reinforcing effects of smoking and some withdrawal symptoms. Another well designed trial demonstrated that extending varenicline therapy by an additional 12 weeks helped maintain abstinence in individuals who had quit smoking. Varenicline was generally well tolerated in clinical trials; nausea, the most commonly occurring adverse event, diminished over time. More data are needed regarding the potential for neuropsychiatric events in varenicline recipients. Some of these events may be associated with nicotine withdrawal, rather than varenicline, although neuropsychiatric events have been observed in individuals who continued to smoke whilst receiving varenicline. In modelled cost-effectiveness analyses based on data from clinical trials in participants receiving smoking cessation therapy, 12 weeks' treatment with varenicline was predicted to be cost effective from a healthcare payer perspective in numerous countries. With regard to the incremental costs per QALY or life-year gained, 12 weeks' treatment with varenicline consistently dominated bupropion SR and nicotine replacement therapy and was dominant over or considered cost effective relative to unaided cessation, regular brief counselling or nortriptyline in analyses based on Markov models. In additional modelled analyses from a healthcare payer perspective, administering varenicline for an additional 12 weeks in participants who had successfully quit smoking was estimated to have acceptable incremental costs per QALY gained relative to varenicline for 12 weeks and to dominate other smoking cessation options. Moreover, in Swedish analyses that also included societal costs for production and consumption, the incremental cost per QALY gained for varenicline versus bupropion SR, and for an additional 12 weeks of varenicline therapy versus varenicline for 12 weeks only, was below commonly accepted thresholds of cost effectiveness. A US decision-analytic model from the perspective of various US health insurance plans demonstrated that, after 2 years, varenicline was predicted to dominate bupropion SR, in terms of the incremental cost per additional smoking cessation. Varenicline was also dominant or cost effective versus nicotine replacement therapy, and cost effective versus unaided cessation. Sensitivity analyses demonstrated that the results of cost-effectiveness studies were generally robust to plausible variations in key parameters. In conclusion, varenicline is an effective aid to smoking cessation. Varenicline was generally well tolerated in clinical trials, although more data are needed regarding the potential for neuropsychiatric events. The costs associated with varenicline are offset by direct savings associated with the reduction in smoking-related diseases. Despite their limitations, available pharmacoeconomic analyses from numerous countries support the use of varenicline for 12 or 24 weeks as a cost-effective treatment relative to other smoking cessation therapies in smokers who wish to quit smoking.