Smoking is the major avoidable cause of preventable morbidity and premature mortality in the United Kingdom and internationally.1 2 Researchers have estimated that smoking related illnesses cost the National Health Service (NHS) about £5bn (€7bn, $8bn) annually.3 Varenicline was first licensed in the UK in 2006. Randomised controlled trials have shown it to be the most clinically effective drug for short term abstinence in smoking cessation.4 Concerns about its neuropsychiatric safety, however, led the Medicines and Healthcare Products Regulatory Agency (MHRA) to issue warnings about varenicline in the UK in 2008.5 Similarly, since 2009, the United States Food and Drug Administration (FDA) has required the addition of a black box warning (the strongest safety warning that can be issued by the agency) to the labelling of varenicline.6 These warnings were based on spontaneous reports of adverse drug reactions from the yellow card scheme and the FDA adverse events reporting system.
