2 The technology
2.1 Varenicline (Champix, Pfizer) has marketing authorisation for smoking cessation in adults. The summary of product characteristics (SPC) states that smokers should set a date to stop smoking and treatment with varenicline should start 1 to 2 weeks before this date and that smoking cessation therapies are more likely to succeed for patients who are provided with additional advice and support.
2.2 Varenicline binds with high affinity and selectivity at the α4β2 neuronal nicotinic acetylcholine receptor, where it acts as a partial agonist. Its binding both alleviates symptoms of craving and withdrawal, and reduces the rewarding and reinforcing effects of smoking by preventing nicotine binding to α4β2 receptors.
2.3 Varenicline may be associated with nausea and other gastrointestinal disorders such as vomiting. For full details of side effects and contraindications, see the SPC.
2.4 Varenicline is available in 0.5-mg and 1-mg film-coated tablets. The cost is £54.60 for a 56-blister pack of 0.5- or 1-mg tablets ('British national formulary' [BNF] edition 53). A 12-week course of treatment costs about £163.80. The SPC specifies the option of an additional 12 weeks of treatment and the consideration of dose tapering. Costs may vary in different settings because of negotiated procurement discounts.