Kate Cahill

Efficacy of interventions to combat tobacco addiction: Cochrane update of 2012 reviews.

BACKGROUND AND AIMS The Cochrane Collaboration is an international not-for-profit organization which produces and disseminates systematic reviews of health-care interventions. This paper is the first in a series of annual updates of Cochrane reviews on tobacco addiction interventions. It also provides an up-to-date overview of review findings in this area to date and summary statistics for cessation reviews in which meta-analyses were conducted. METHODS In 2012, the Group published seven new reviews and updated 13 others. This update summarizes and comments on these reviews. It also summarizes key findings from all the other reviews in this area. RESULTS New reviews in 2012 found that in smokers using pharmacotherapy, behavioural support improves success rates [risk ratio (RR) 1.16, 95% confidence interval (CI) = 1.09-1.24], and that combining behavioural support and pharmacotherapy aids cessation (RR 1.82, 95% CI = 1.66-2.00). Updated reviews established mobile phones as potentially helpful in aiding cessation (RR 1.71, 95% CI = 1.47-1.99), found that cytisine (RR 3.98, 95% CI = 2.01-7.87) and low-dose varenicline (RR 2.09, 95% CI = 1.56-2.78) aid smoking cessation, and found that training health professionals in smoking cessation improves patient cessation rates (RR 1.60, 95% CI = 1.26-2.03). The updated reviews confirmed the benefits of nicotine replacement therapy, standard dose varenicline and providing cessation treatment free of charge. Lack of demonstrated efficacy remained for partner support, expired-air carbon monoxide feedback and lung function feedback. CONCLUSIONS Cochrane systematic review evidence for the first time establishes the efficacy of behavioural support over and above pharmacotherapy, as well as the efficacy of cytisine, mobile phone technology, low-dose varenicline and health professional training in promoting smoking cessation.

Pharmacological treatments for smoking cessation.

CLINICAL QUESTION Among the 3 first-line smoking cessation treatments (nicotine replacement therapy [NRT], bupropion, and varenicline), which is most effective in helping people who smoke achieve and maintain abstinence from smoking for at least 6 months, and what serious adverse events are associated with each? BOTTOM LINE Higher rates of smoking cessation were associated with NRT (17.6%) and bupropion (19.1%) compared with placebo (10.6%). Varenicline (27.6%) and combination NRT (31.5%) (eg, patch plus inhaler) were most effective for achieving smoking cessation. None of the therapies was associated with an increased rate of serious adverse events.

A Preliminary Benefit-Risk Assessment of Varenicline in Smoking Cessation

Varenicline is a recently developed medication for smoking cessation, which has been available on prescription since 2006. It is a selective nicotinic acetylcholine receptor partial agonist, and is designed to reduce withdrawal symptoms and to lessen the rewards of continued smoking. Our objective in this article is to assess the efficacy of varenicline as an aid to smoking cessation and to weigh the potential benefits against the possible risks. We identified ten randomized controlled trials and one cohort study with historical controls. In total there were 7999 participants, 5112 of whom received varenicline. Eight of the trials compared varenicline with placebo for cessation, two compared it with nicotine replacement therapy and one tested extended use for relapse prevention. Three of the varenicline/placebo trials also included a bupropion arm. The recommended dosage of varenicline 1 mg twice daily more than doubled the chances of quitting at 6 months or longer, with a relative risk (RR) compared with placebo of 2.38 (95% CI 2.00, 2.84). It also outperformed bupropion (RR 1.52 [95% CI 1.22, 1.88]) and nicotine replacement (RR 1.31 [95%CI 1.01,1.71]). A reduced dosage regimen of 1 mg daily also increased cessation (RR 1.88 [95% CI 1.35, 2.60]). In the trials, varenicline significantly reduced craving and other withdrawal symptoms. The most frequent adverse event was nausea, occurring in 30–40% of varenicline users. However, this was generally reported at mild to moderate levels, diminished over time and was associated with attributable discontinuation rates of between 0.6% and 7.6%. Other commonly occurring adverse events included insomnia, abnormal dreams and headache. Serious adverse events were rare, with no treatment-related deaths during the treatment or follow-up phases.Postmarketing surveillance has raised new questions about the safety of varenicline. In February 2008, the US FDA issued a public health advisory note, reporting a possible association between varenicline and an increased risk of behaviour change, agitation, depressed mood, and suicidal ideation and behaviour. They have required the manufacturers to revise the labelling of varenicline and the Summary of Product Characteristics, and to issue a medication guide. It is arguable that much of the reported behavioural and mood changes may be associated with nicotine withdrawal, although some effects occurred in people who continued to smoke while taking the medication. In view of the potential, if unproven, risk that varenicline may be associated with serious neuropsychiatric adverse outcomes, patients attempting to quit smoking with varenicline, and their families and caregivers, should be alerted about the need to monitor for neuropsychiatric symptoms, including changes in behaviour, agitation, depressed mood, suicidal ideation and sui-cidal behaviour, and to report such symptoms immediately to the patient’s healthcare provider.

Efficacy of interventions to combat tobacco addiction: Cochrane update of 2013 reviews: Cochrane update of 2013 reviews

AIMS The Cochrane Collaboration is an international not-for profit organization which produces and disseminates systematic reviews. This paper is the second in a series of annual updates of Cochrane reviews on tobacco addiction interventions, covering new and updated reviews from 2013. METHODS In 2013, the Group published two new reviews and updated 11 others. This update summarizes and comments on these reviews as well as on a review of psychosocial interventions for smoking cessation in pregnant women, and presents pooled results from reviews of cessation interventions. RESULTS New reviews in 2013 found: low-quality evidence that behavioural interventions with mood management components could significantly increase long-term quit rates in people with current [risk ratio (RR) = 1.47, 95% confidence interval (CI) = 1.13-1.92) and past (RR = 1.41, 95% CI = 1.13-1.77] depression; evidence from network meta-analysis that varenicline and combined forms of nicotine replacement therapy (NRT) are associated with higher quit rates than bupropion or single-form NRT (varenicline versus single-form NRT odds ratio (OR) = 1.57, 95% credibility interval (CredI) = 1.29-1.91; versus bupropion OR = 1.59, 95% CredI = 1.29-1.96); and no evidence of a significant increase in serious adverse events in trial participants randomized to varenicline or bupropion when compared to placebo controls. New evidence emerging from updated reviews suggests that counselling interventions can increase quit rates in pregnant women and that school-based smoking programmes with social competence curricula can lead to a significant reduction in uptake of smoking at more than a year. Updated reviews also suggested that naltrexone, selective serotonin re-uptake inhibitors and St Johns wort do not have a significant effect on long-term smoking cessation. CONCLUSIONS Cochrane systematic review evidence from 2013 suggests that adding mood management to behavioural support may improve cessation outcomes in smokers with current or past depression and strengthens evidence for previous conclusions, including the safety of varenicline and bupropion and the benefits of behavioural support for smoking cessation in pregnancy.

An update on therapeutics for tobacco dependence

The aim of this review is to consider the clinical trial evidence for the efficacy of four classes of pharmacological treatment for nicotine dependence: nicotine replacement, antidepressants, nicotine-receptor partial agonists and drugs blocking cannabinoid receptors. Despite falls in many developed countries, the prevalence of smoking remains high and is increasing in developing countries. Stopping smoking before middle age substantially reduces the mortality associated with tobacco use. Although many people quit without formal help, both non-pharmacological and pharmacological interventions can help people to stop smoking. Drug therapies target neural pathways to reduce withdrawal symptoms associated with psychopharmacological dependence on nicotine. Nicotine replacement therapy and some antidepressants aid smoking cessation and are an established part of therapy. Newer pharmacological approaches include the use of the selective nicotinic partial agonists, varenicline and cytisine, and compounds targeting cannabinoid receptors (rimonabant). Recent evidence suggests that the nicotine-receptor partial agonist varenicline is at least as effective as nicotine replacement therapy and antidepressants.