Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet

Varenicline is an effective pharmacotherapy to aid smoking cessation. However, its use is limited by continuing concerns about possible associated risks of serious adverse cardiovascular and neuropsychiatric events. The aim of this study was to investigate whether use of varenicline is associated with such events. In this retrospective cohort study, we used data from patients included in the validated QResearch database, which holds data from 753 National Health Service general practices across England. We identified patients aged 18-100 years (registered for longer than 12 months before data extraction) who received a prescription of nicotine replacement treatment (NRT; reference group), bupropion, or varenicline. We excluded patients if they had used one of the drugs during the 12 months before the start date of the study, had received a prescription of a combination of these drugs during the follow-up period, or were temporary residents. We followed patients up for 6 months to compare incident cardiovascular (ischaemic heart disease, cerebral infarction, heart failure, peripheral vascular disease, and cardiac arrhythmia) and neuropsychiatric (depression and self-harm) events using Cox proportional hazards models, adjusted for potential confounders (primary outcomes). We identified 164,766 patients who received a prescription (106,759 for nicotine replacement treatment; 6557 for bupropion; 51,450 for varenicline) between Jan 1, 2007, and June 30, 2012. Neither bupropion nor varenicline showed an increased risk of any cardiovascular or neuropsychiatric event compared with NRT (all hazard ratios [HRs] less than 1. Varenicline was associated with a significantly reduced risk of ischaemic heart disease (HR 0.80 [95%CI 0.72-0.87]), cerebral infarction (0.62 [0.52-0.73]), heart failure (0.61 [0.45-0.83]), arrhythmia (0.73 [0.60-0.88]), depression (0.66 [0.63-0.69]), and self-harm (0.56 [0.46-0.68]). Varenicline does not seem to be associated with an increased risk of documented cardiovascular events, depression, or self-harm when compared with NRT. Adverse events that do not come to attention of general practitioners cannot be excluded. These findings suggest an opportunity for physicians to prescribe varenicline more broadly, even for patients with comorbidities, thereby helping more smokers to quit successfully than do at present. Egton Medical Information Systems, University of Nottingham, Ministry of Innovation, Science and Research of the German Federal State of North Rhine-Westphalia, Cancer Research UK, Medical Research Council, Commonwealth Fund.

To estimate the "real-world" effectiveness of commonly used aids to smoking cessation in England by using longitudinal data. We conducted a prospective cohort study in 1560 adult smokers who participated in an English national household survey in the period from November 2006 to March 2012, responded to a 6-month follow-up survey, and made at least 1 quit attempt between the 2 measurements. The quitting method was classified as follows: (1) prescription medication (nicotine replacement therapy [NRT], bupropion, or varenicline) in combination with specialist behavioral support delivered by a National Health Service Stop Smoking Service; (2) prescription medication with brief advice; (3) NRT bought over the counter; (4) none of these. The primary outcome measure was self-reported abstinence up to the time of the 6-month follow-up survey, adjusted for key potential confounders including cigarette dependence. Compared with smokers using none of the cessation aids, the adjusted odds of remaining abstinent up to the time of the 6-month follow-up survey were 2.58 (95% CI, 1.48-4.52) times higher in users of prescription medication in combination with specialist behavioral support and 1.55 (95% CI, 1.11-2.16) times higher in users of prescription medication with brief advice. The use of NRT bought over the counter was associated with a lower odds of abstinence (odds ratio, 0.68; 95% CI, 0.49-0.94). Prescription medication offered with specialist behavioral support and that offered with minimal behavioral support are successful methods of stopping cigarette smoking in England.