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ABSTRACT

OBJECTIVE

To review the evidence on the efficacy and safety of pharmacologic and nonpharmacologic therapies for smoking cessation.

QUALITY OF EVIDENCE

MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched for randomized controlled trials, meta-analyses, and systematic reviews (level I evidence) pertinent to pharmacologic and nonpharmacologic smoking cessation therapies.

MAIN MESSAGE

Pharmacologic smoking cessation aids are recommended for all smokers trying to quit, unless contraindicated. A new pharmacologic smoking cessation aid, varenicline, is now available in Canada. Level I evidence at 1-year follow-up indicates that it is effective for smoking cessation. Adverse effects include nausea, insomnia, and abnormal dreaming. Nausea is mild or moderate and decreases over time. Varenicline is more effective than placebo or bupropion. Counseling also increases the likelihood of achieving cessation.

CONCLUSION

Preliminary data indicate that varenicline is more effective than other available pharmacologic smoking cessation aids. Pharmacologic therapy should be combined with nonpharmacologic therapy.

Background:

There have been postmarketing reports of adverse cardiovascular events associated with the use of varenicline, a widely used smoking cessation drug. We conducted a systematic review and meta-analysis of randomized controlled trials to ascertain the serious adverse cardiovascular effects of varenicline compared with placebo among tobacco users.

Methods:

We searched MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, websites of regulatory authorities and registries of clinical trials, with no date or language restrictions, through September 2010 (updated March 2011) for published and unpublished studies. We selected double-blind randomized controlled trials of at least one week’s duration involving smokers or people who used smokeless tobacco that reported on cardiovascular events (ischemia, arrhythmia, congestive heart failure, sudden death or cardiovascular-related death) as serious adverse events asociated with the use of varenicline.

Results:

We analyzed data from 14 double-blind randomized controlled trials involving 8216 participants. The trials ranged in duration from 7 to 52 weeks. Varenicline was associated with a significantly increased risk of serious adverse cardiovascular events compared with placebo (1.06% [52/4908] in varenicline group v. 0.82% [27/3308] in placebo group; Peto odds ratio [OR] 1.72, 95% confidence interval [CI] 1.09–2.71; I2 = 0%). The results of various sensitivity analyses were consistent with those of the main analysis, and a funnel plot showed no publication bias. There were too few deaths to allow meaningful comparisons of mortality.

Interpretation:

Our meta-analysis raises safety concerns about the potential for an increased risk of serious adverse cardiovascular events associated with the use of varenicline among tobacco users.

In this double-blind, placebo-controlled trial, we compared varenicline (2 mg) to placebo for treatment for cocaine and tobacco dependence in 31 methadone-maintained subjects. Subjects received weekly counseling during the 12-week study participation. Our results indicate that varenicline is safe to give to this subject population, as there were no adverse events related to medication during this study. Varenicline was no more effective than placebo for abstinence from cocaine. Treatment with varenicline was associated with a reduced number of cigarettes smoked per day, even though subjects received only a brief education for smoking cessation. The self-report reduction in smoking was corroborated by CO levels and the Fagerström Test of Nicotine Dependence. However, self-ratings of positive mood on the Positive Affect Negative Affect Schedule did significantly decrease in the varenicline group as compared to the placebo group, although this appears to be due to randomization differences related to lifetime depression diagnosis. These preliminary findings may point to potential therapeutic value of varenicline for smoking cessation in cocaine users maintained on methadone.

Rationale

Varenicline, a partial nicotinic acetylcholine receptor (nAChR) agonist, is approved for smoking cessation. A few preclinical studies examined the pharmacological effects of varenicline, alone or in combination with nicotine. How varenicline affects the pharmacological effects of pure nicotine has not been examined in humans. The goal of this study was to characterize varenicline’s actions on nicotine’s dose-dependent effects in abstinent smokers.

Methods

Six male and 6 female smokers participated in a double-blind, placebo-controlled, crossover study. Smokers had two, 4-day treatment periods, assigned in random sequence, to varenicline (1 mg/day) or placebo treatment. On day 4 of each treatment phase, smokers had an experimental session, where they received 3 escalating doses of intravenous (IV) nicotine (0.1, 0.4, and 0.7 mg/70 kg), in 30 minute intervals. Varenicline’s effects were assessed through subjective, physiological and cognitive performance outcomes to nicotine administered via IV route.

Results

In response to IV nicotine, varenicline treatment attenuated the rating of drug strength, high, head rush, and stimulated. Varenicline also attenuated nicotine-induced increases in heart rate. Varenicline had mixed effects on cognitive performance. Smokers under varenicline treatment, compared with placebo, reported enhanced positive mood measured with the Positive and Negative Affect Schedule (PANAS).

Conclusions

These findings provide new insights into the mechanisms of action of varenicline in smoking cessation.

Abstract

The prevalence of smoking in HIV-infected subjects is high. As a smoking cessation aid, varenicline (Champix®, Pfizer, Saint-Laurent, QC, Canada or Chantix®, Pfizer, Mission, KS) has not been previously evaluated in HIV-infected smokers. In this multicenter pilot open label study, varenicline 1.0 mg was used twice daily for 12 weeks with dose titration in the first week. Adverse events (AEs) during the treatment period were recorded. Changes from baseline in laboratory tests, vital signs, daily cigarette consumption, nicotine dependence, and withdrawal were measured through week 24. Self-reported abstinence was validated by serum cotinine at week 12. We enrolled 36 subjects with a mean of 29 pack-years of smoking and a minimum of 4 cigarettes per day. All but 1 were male, 33 (92%) were white. The most frequently reported AEs were nausea (33%), abnormal dreams (31%), affect lability (19%), and insomnia (19%). Six (17%) subjects discontinued varenicline due to AEs. No grade 3/4 laboratory abnormalities or serious AEs occurred during the study. There was no significant change in HIV viral load. CD4 counts increased by 69 cells/mm3 (p=0.001) at week 24. Serum cotinine-verified 4-week continuous abstinence rate through weeks 9–12 was 42% (95% confidence interval [CI]: 26–58%). AEs and abstinence rates were comparable to those in published randomized controlled trials conducted in generally healthy HIV-negative smokers. Varenicline was safe and appears effective among HIV-infected smokers in this exploratory study, although AEs were common. The most common AE was nausea, with no adverse effect on HIV treatment outcome. Close monitoring of liver enzymes and blood pressure is recommended for HIV-positive smokers taking varenicline.

Introduction:

Despite tremendous potential public health impact, little work has focused on development of evidence-based smoking cessation treatments for adolescents, including pharmacotherapies. No prior studies have explored the feasibility and safety of varenicline and bupropion XL, 2 potentially promising pharmacotherapies, as smoking cessation treatments in adolescents.

Methods:

Treatment-seeking older adolescent smokers (ages 15–20) were randomized (double-blind) to varenicline (n = 15) or bupropion XL (n = 14), with 1-week titration and active treatment for 7 weeks. Structured safety, tolerability, and efficacy assessments (cotinine-confirmed 7-day point prevalence abstinence) were conducted weekly.

Results:

There were no serious adverse events. Two participants discontinued bupropion XL due to adverse effects, and none discontinued varenicline. Over the course of treatment, participants receiving varenicline reduced from 14.1 ± 6.3 (mean ± SD) to 0.9 ± 2.1 cigarettes/day (CPD, 4 achieved abstinence), while those receiving bupropion XL reduced from 15.8 ± 4.4 to 3.1 ± 4.0 CPD (2 achieved abstinence).

Conclusions:

These preliminary results support the feasibility and safety of conducting adequately powered, placebo-controlled efficacy studies of varenicline and bupropion XL for adolescent smoking cessation.

Smoking is the leading preventable cause of morbidity and mortality in the US, and decreasing smoking prevalence is a public health priority. Patients achieve the greatest success when quit attempts involve behavioral therapy combined with pharmacotherapy. Varenicline is the most recent addition to the pharmacotherapeutic armamentarium for the treatment of tobacco dependence. Varenicline is efficacious and cost-effective. Smoking relapse and adverse treatment-related side effects may decrease medication adherence and patient satisfaction with varenicline. In the clinical setting, varenicline treatment can be optimized by reducing doses in patients who experience intolerable side effects, increasing the dose in partial responders, and providing long-term maintenance therapy for relapse prevention.

Objectives

Varenicline was approved by the FDA in 2006. In 2009, based largely on case reports, the FDA issued a warning of possible adverse neuropsychiatric effects including depression and suicidal thoughts and behavior for varenicline and bupropion. Prospective trials of varenicline have not reported increased incidence of psychiatric adverse events other than sleep disturbance, but smokers with major mental illness have been excluded from large prospective trials of varenicline to date. We sought to evaluate the effect of a standard open-label 12-week varenicline trial on prospectively assessed safety and smoking outcomes in stable, treated adults with schizophrenia spectrum disorder and nicotine dependence.

Methods

One-hundred-and-twelve stable outpatients who smoked >10 cigarettes/day participated in a 12-week, open-label, smoking cessation trial of varenicline and weekly group cognitive behavioral therapy. Participants took varenicline for 4 weeks before attempting cessation. Trained raters collected safety and smoking outcome data weekly.

Results

Participants demonstrated improved psychotic symptoms, depressive symptoms and nicotine withdrawal symptoms from baseline to week 12 or early termination. At the end of 12 weeks open label treatment, the 14- and 28-day continuous abstinence rates were 47.3 and 34%, respectively. Expired CO declined significantly during treatment in those who did not achieve abstinence.

Conclusions

This prospective study suggests that varenicline may be well-tolerated and effective for smoking cessation in combination with group CBT in stable outpatients with schizophrenia, a group with high rates of smoking and smoking-attributable morbidity and mortality.

Background

Many placebo-controlled trials have demonstrated the efficacy of individual pharmacotherapies approved for smoking cessation. However, few direct or indirect comparisons of such interventions have been conducted. We performed a meta-analysis to compare the treatment effects of 7 approved pharmacologic interventions for smoking cessation.

Methods

We searched the US Centers for Disease Control and Prevention's Tobacco Information and Prevention database as well as MEDLINE, EMBASE and the Cochrane Library for published reports of placebo-controlled, double-blind randomized controlled trials of pharmacotherapies for smoking cessation. We included studies that reported biochemically validated measures of abstinence at 6 and 12 months. We used a hierarchical Bayesian random-effects model to summarize the results for each intervention.

Results

We identified 70 published reports of 69 trials involving a total of 32 908 patients. Six of the 7 pharmacotherapies studied were found to be more efficacious than placebo: varenicline (odds ratio [OR] 2.41, 95% credible interval [CrI] 1.91–3.12), nicotine nasal spray (OR 2.37, 95% CrI 1.12–5.13), bupropion (OR 2.07, 95% CrI 1.73–2.55), transdermal nicotine (OR 2.07, 95% CrI 1.69–2.62), nicotine tablet (OR 2.06, 95% CrI 1.12–5.13) and nicotine gum (OR 1.71, 95% CrI 1.35–2.21). Similar results were obtained regardless of which measure of abstinence was used. Although the point estimate favoured nicotine inhaler over placebo (OR 2.17), these results were not conclusive because the credible interval included unity (95% CrI 0.95–5.43). When all 7 interventions were included in the same model, all were more efficacious than placebo. In our analysis of data from the varenicline trials that included bupropion control arms, we found that varenicline was superior to bupropion (OR 2.18, 95% CrI 1.09–4.08).

Interpretation

Varenicline, bupropion and the 5 nicotine replacement therapies were all more efficacious than placebo at promoting smoking abstinence at 6 and 12 months.

Objective To examine the risk of treatment emergent, cardiovascular serious adverse events associated with varenicline use for tobacco cessation.

Design Meta-analysis comparing study effects using four summary estimates.

Data sources Medline, Cochrane Library, online clinical trials registries, and reference lists of identified articles.

Review methods We included randomised controlled trials of current tobacco users of adult age comparing use of varenicline with an inactive control and reporting adverse events. We defined treatment emergent, cardiovascular serious adverse events as occurring during drug treatment or within 30 days of discontinuation, and included any ischaemic or arrhythmic adverse cardiovascular event (myocardial infarction, unstable angina, coronary revascularisation, coronary artery disease, arrhythmias, transient ischaemic attacks, stroke, sudden death or cardiovascular related death, or congestive heart failure).

Results We identified 22 trials; all were double blinded and placebo controlled; two included participants with active cardiovascular disease and 11 enrolled participants with a history of cardiovascular disease. Rates of treatment emergent, cardiovascular serious adverse events were 0.63% (34/5431) in the varenicline groups and 0.47% (18/3801) in the placebo groups. The summary estimate for the risk difference, 0.27% (95% confidence interval −0.10 to 0.63; P=0.15), based on all 22 trials, was neither clinically nor statistically significant. For comparison, the relative risk (1.40, 0.82 to 2.39; P=0.22), Mantel-Haenszel odds ratio (1.41, 0.82 to 2.42; P=0.22), and Peto odds ratio (1.58, 0.90 to 2.76; P=0.11), all based on 14 trials with at least one event, also indicated a non-significant difference between varenicline and placebo groups.

Conclusions This meta-analysis—which included all trials published to date, focused on events occurring during drug exposure, and analysed findings using four summary estimates—found no significant increase in cardiovascular serious adverse events associated with varenicline use. For rare outcomes, summary estimates based on absolute effects are recommended and estimates based on the Peto odds ratio should be avoided.

Varenicline promotes smoking cessation and reduces urges to smoke. However, the mechanisms associated with these effects and their time course are not well characterized. One mechanism may be extinction, but the duration of the current dosing protocol may not be sufficient. We examined the effect of extended pre-treatment with varenicline on smoking behavior among 17 non-treatment seeking adult smokers. Using a within-subjects, double-blind, placebo-controlled crossover design, participants received standard dosing of varenicline for 21 days, followed by a 14-day washout period and 21 days of placebo; order counterbalanced. Cigarettes per day (CPD), smoking topography, smoking urges (QSU), and side effects were assessed every three days. Biomarkers (e.g. nicotine metabolites) were collected on days 1, 7, and 21. There was a significant drug by time interaction indicating a reduction in CPD during varenicline phase (between days 10–21), but no reduction during placebo. Varenicline also led to reductions in nicotine metabolites and urges to smoke. Among this sample of non-treatment seeking smokers, varenicline significantly reduced smoking behavior. Results have important treatment implications because changes in CPD and craving did not occur until after the typical one-week run-up period. This suggests that a longer duration of pre-treatment may be beneficial for some smokers.

Background

Smoking remains the leading preventable cause of premature deaths. Several pharmacological interventions now exist to aid smokers in cessation. These include Nicotine Replacement Therapy [NRT], bupropion, and varenicline. We aimed to assess their relative efficacy in smoking cessation by conducting a systematic review and meta-analysis.

Methods

We searched 10 electronic medical databases (inception to Sept. 2006) and bibliographies of published reviews. We selected randomized controlled trials [RCTs] evaluating interventions for smoking cessation at 1 year, through chemical confirmation. Our primary endpoint was smoking cessation at 1 year. Secondary endpoints included short-term smoking cessation (~3 months) and adverse events. We conducted random-effects meta-analysis and meta-regression. We compared treatment effects across interventions using head-to-head trials and when these did not exist, we calculated indirect comparisons.

Results

We identified 70 trials of NRT versus control at 1 year, Odds Ratio [OR] 1.71, 95% Confidence Interval [CI], 1.55–1.88, P =< 0.0001). This was consistent when examining all placebo-controlled trials (49 RCTs, OR 1.78, 95% CI, 1.60–1.99), NRT gum (OR 1.60, 95% CI, 1.37–1.86) or patch (OR 1.63, 95% CI, 1.41–1.89). NRT also reduced smoking at 3 months (OR 1.98, 95% CI, 1.77–2.21). Bupropion trials were superior to controls at 1 year (12 RCTs, OR1.56, 95% CI, 1.10–2.21, P = 0.01) and at 3 months (OR 2.13, 95% CI, 1.72–2.64). Two RCTs evaluated the superiority of bupropion versus NRT at 1 year (OR 1.14, 95% CI, 0.20–6.42).

Varenicline was superior to placebo at 1 year (4 RCTs, OR 2.96, 95% CI, 2.12–4.12, P =< 0.0001) and also at approximately 3 months (OR 3.75, 95% CI, 2.65–5.30). Three RCTs evaluated the effectiveness of varenicline versus bupropion at 1 year (OR 1.58, 95% CI, 1.22–2.05) and at approximately 3 months (OR 1.61, 95% CI, 1.16–2.21). Using indirect comparisons, varenicline was superior to NRT when compared to placebo controls (OR 1.66, 95% CI 1.17–2.36, P = 0.004) or to all controls at 1 year (OR 1.73, 95% CI 1.22–2.45, P = 0.001). This was also the case for 3-month data. Adverse events were not systematically different across studies.

Conclusion

NRT, bupropion and varenicline all provide therapeutic effects in assisting with smoking cessation. Direct and indirect comparisons identify a hierarchy of effectiveness.

A prospective pragmatic interventional study was conducted to evaluate the effectiveness of varenicline for smoking cessation among a cohort of motivated smokers attending two smoking cessation clinics. Smokers between 18 and 65 years who had smoked 10 or more cigarettes per day were included. All participants received cognitive-behavioural varenicline according to approved dose and prescriptions. Continuous abstinence, validated by exhaled CO levels, was assessed in each control. A total of 264 smokers – 155 males (58.7%) and 109 females (41.3%) – were included. Mean age was 43.7, amount smoked was 23 cigarettes per day and 61.4% had at least one prior attempt to quit. The continuous abstinence rate at end of treatment (12 wks) was 58.3%. Conclusions: varenicline and cognitive-behavioural intervention are effective for smoking cessation with high continuous abstinence rates when are used in a clinical setting.

Objective To assess the efficacy and safety of varenicline (a licensed cigarette smoking cessation aid) in helping users of smokeless tobacco to quit.

Design Double blind, placebo controlled, parallel group, multicentre, randomised controlled trial.

Setting Medical clinics (mostly primary care) in Norway and Sweden.

Participants Men and women aged ≥18 who used smokeless tobacco at least eight times a day, with no abstinence period over three months within one year before screening, who wanted to quit all tobacco use. Participants were excluded if they used any other form of tobacco (except smokeless tobacco) or medication to stop smoking within three months of screening or had any pre-existing medical or psychiatric condition.

Interventions Varenicline 1 mg twice daily (titrated during the first week) or placebo for 12 weeks, with 14 weeks’ follow-up after treatment.

Main outcome measures The primary end point was the four week continuous abstinence rate at the end of treatment (weeks 9-12) confirmed with cotinine concentration. A secondary end point was continuous abstinence rate for weeks 9-26. Safety and tolerability were also evaluated.

Results 431 participants (213 varenicline; 218 placebo) were randomised and received at least one dose of study drug. Participants’ demographics and baseline use of smokeless tobacco were similar (89% (189) and 90% (196), respectively, were men; mean age in both groups was 43.9; participants used smokeless tobacco products about 15 times a day, and about 80% first used smokeless tobacco within 30 minutes after awakening). Continuous abstinence rate at week 9-12 was higher in the varenicline group than the placebo group (59% (125) v 39% (85); relative risk 1.60, 95% confidence interval 1.32 to 1.87, P<0.001; risk difference 20%; number needed to treat 5). The advantage of varenicline over placebo persisted through 14 weeks of follow-up (continuous abstinence rate at week 9-26 was 45% (95) v 34% (73); relative risk 1.42, 1.08 to 1.79, P=0.012; risk difference 11%; number needed to treat 9). The most common adverse events in the varenicline group compared with the placebo group were nausea (35% (74) v 6% (14)), fatigue (10% (22) v 7% (15)), headache (10% (22) v 9% (20)), and sleep disorder (10% (22) v 7% (15)). Few adverse events led to discontinuation of treatment (9% (19) and 4% (9), respectively), and serious adverse events occurred in two (1%) and three (1%) participants, respectively.

Conclusion Varenicline can help people to give up smokeless tobacco and has an acceptable safety profile. The response rate in the placebo group in this study was high, suggesting a population less resistant to treatment than smokers.

Trial Registration NCT00717093.

There is a lack of evidence of the relative cost-effectiveness of proactive telephone counseling (PTC) and Web-based delivery of smoking cessation services in conjunction with pharmacotherapy. We calculated the differential cost-effectiveness of three behavioral smoking cessation modalities with varenicline treatment in a randomized trial of current smokers from a large health system. Eligible participants were randomized to one of three smoking cessation interventions: Web-based counseling (n=401), PTC (n=402), or combined PTC-Web counseling (n=399). All participants received a standard 12-week course of varenicline. The primary outcome was a 7-day point prevalent nonsmoking at the 6month follow-up. The Web intervention was the least expensive followed by the PTC and PTC-Web groups. Costs per additional 6-month nonsmoker and per additional lifetime quitter were $1,278 and $2,601 for Web, $1,472 and $2,995 for PTC, and $1,617 and $3,291 for PTC-Web. Cost per life-year (LY) and quality-adjusted life-year (QALY) saved were $1,148 and $1,136 for Web, $1,320 and $1,308 for PTC, and $1,450 and $1,437 for PTC-Web. Based on the cost per LY and QALY saved, these interventions are among the most cost-effective life-saving medical treatments. Web, PTC, and combined PTC-Web treatments were all highly cost-effective, with the Web treatment being marginally more cost-effective than the PTC or combined PTC-Web treatments.

Introduction:

Patient adherence to smoking cessation medications can impact their effectiveness. It is important to understand the extent to which prescribed medications are actually taken by smokers, how this influences smoking cessation outcomes, and what factors may influence adherence.

Methods:

Smokers recruited from a large health plan were randomized to receive different modes of cessation counseling in combination with varenicline (Swan, G. E., McClure, J. B., Jack, L. M., Zbikowski, S. M., Javitz, H. S., Catz, S. L., et al. 2010.Behavioral counseling and varenicline treatment for smoking cessation. American Journal of Preventive Medicine, 38, 482–490). One thousand one hundred and sixty-one participants were mailed a 28-day varenicline supply when they set a quit date and were able to request up to two refills from the health plan pharmacy at no cost. Pharmacy fill records were obtained and telephone surveys completed at baseline, 21 days, 12 weeks, and 6 months post target quit date.

Results:

Good adherence to varenicline (≥80% of days taken) was associated with a twofold increase in 6-month quit rates compared with poor adherence (52% vs. 25%). Smokers were more likely than nonsmokers to stop varenicline early. Purposeful nonadherence was associated with smoking at 12 weeks and was predicted in multivariate analyses by age, gender, adherence self-efficacy, and initial medication side effect severity.

Conclusions:

Innovative methods for increasing adherence to smoking cessation medications are needed, particularly early in the quit process. Simple metrics of adherence such as number of days cessation medication is taken can and should be routinely incorporated in effectiveness trials and reported to advance future attempts to understand and reduce nonadherence.

The aim of this study is to examine the effects of treatment with varenicline, a partial agonist at the α4β2 and full agonist at the α7 nicotine acetylcholine receptor, on cognitive impairments in people with schizophrenia. In all, 120 clinically stable people with schizophrenia participated in randomized, double-blind, placebo-controlled 8-week trial. Antipsychotic and concomitant medication doses remained fixed throughout the study. Varenicline was titrated up to 1 mg twice daily for weeks 2–8. Neuropsychological, clinical, and safety assessments were administered at baseline and weeks 1, 2, 4, and 8. In the primary analyses of neurocognitive differences at week 8, no varenicline–placebo differences were significant. In secondary longitudinal analyses, varenicline improved compared with placebo on the Digital Symbol Substitution Test (p=0.013) and the Wisconsin Card Sorting Test non-perseverative errors (p=0.043). Some treatment effects were different between smokers and non-smokers. In smokers, Continuous Performance Test hit reaction time (p=0.008) and Stroop Interference (p=0.004) were reduced for varenicline compared with placebo, while there were no treatment differences in non-smokers. No significant treatment main effects or interactions were noted for total scores on the Positive and Negative Syndrome Scale or the Scale for the Assessment for Negative Symptoms. Our findings suggest beneficial effects of adjunctive varenicline treatment with antipsychotics for some cognitive impairments in people with schizophrenia. In some cases, effects of treatment varied between smokers and non-smokers. Further study is required to assess the functional significance of these changes.

Introduction:

Current smoking cessation guidelines recommend setting a quit date prior to starting pharmacotherapy. However, providing flexibility in the date of quitting may be more acceptable to some smokers. The objective of this study was to compare varenicline 1 mg twice daily (b.i.d.) with placebo in subjects using a flexible quit date paradigm after starting medication.

Methods:

In this double-blind, randomized, placebo-controlled international study, smokers of ≥10 cigarettes/day, aged 18–75 years, and who were motivated to quit were randomized (3:1) to receive varenicline 1 mg b.i.d. or placebo for 12 weeks. Subjects were followed up through Week 24. Subjects were instructed to quit between Days 8 and 35 after starting medication. The primary endpoint was carbon monoxide–confirmed continuous abstinence during Weeks 9–12, and a key secondary endpoint was continuous abstinence during Weeks 9–24.

Results:

Overall, 493 subjects were randomized to varenicline and 166 to placebo. Continuous abstinence was higher for varenicline than for placebo subjects at the end of treatment (Weeks 9–12: 53.1% vs. 19.3%; odds ratio [OR] 5.9; 95% CI, 3.7–9.4; p < .0001) and through 24 weeks follow-up (Weeks 9–24: 34.7% vs. 12.7%; OR 4.4; 95% CI, 2.6–7.5; p < .0001). Serious adverse events occurred in 1.2% varenicline (none were psychiatric) and 0.6% placebo subjects. Fewer varenicline than placebo subjects reported depression-related adverse events (2.3% vs. 6.7%, respectively).

Conclusions:

Varenicline 1 mg b.i.d. using a flexible quit date paradigm had similar efficacy and safety compared with previous fixed quit date studies.

This paper examines reported symptoms, nonsmoking rates, and medication use among 1018 smokers using varenicline in a randomized trial comparing three forms of behavioral support for smoking cessation (phone, web, or phone + web). One month after beginning varenicline, 168 people (17%) had discontinued the medication. Most (53%) quit due to side-effects and other symptoms. The most common side-effect among all users was nausea (reported by 57% of users). At one month post medication initiation, those not taking varenicline were more likely to report smoking than those who continued the medication (57% vs. 16%, p<.001). Women reported more symptoms but did not discontinue medication at higher rates. Participants who received any telephone counseling (n=681) were less likely to discontinue their medication than those with web support only (15% vs. 21%, p<.01). Counseling may improve tolerance of this medication and reduce the rate of discontinuation due to side-effects. (149 words)

Background

Greece has the highest proportion of smokers in the European Union with 42% of Greeks admitting that they smoke, based on a 2009 survey. This post-hoc analysis of a prospective, observational study evaluated the effectiveness and safety profile of the smoking cessation aid varenicline, as well as potential predictors of quit success in a Greek population.

Methods

Participants were prescribed varenicline according to the recommendations of the European Summary of Product Characteristics (1 mg twice daily). The 7-day point prevalence of abstinence at Week 12 was determined based on verbal reporting using a nicotine use inventory. Abstinence was confirmed by carbon monoxide measurements of exhaled air at the last visit of the study. The safety profile of varenicline was also assessed.

Results

At baseline, the Greek subsample (n = 196) had a mean age of 42.6 years, with 54.6% of them being men. Participants had a smoking history of 23.5 years and a Fagerström Test for Nicotine Dependence total score of 6.6. After 12 weeks of varenicline therapy, 70.4% (95% CI, 64.0-76.7) of all participants had quit smoking. This increased to 86.2% among participants who had taken the study medication for 80% of the planned number of treatment days. Age was a significant predictor of quit success. The most frequently observed treatment-emergent adverse event was nausea, occurring in 13.3% of participants.

Conclusions

In this 'real-world' observational study, 70.4% of Greek smokers successfully quit smoking after 12 weeks of varenicline therapy, providing support that varenicline is an effective smoking cessation medication. Further studies with longer follow-up are warranted.

Trial Registration

ClinicalTrials.gov: NCT00669240

Background

Varenicline is an effective smoking cessation aid. However, smokers prescribed with varenicline do not always receive varenicline for 12 weeks, as recommended. This study analyzed the subjects who received varenicline and investigated the effect of varenicline treatment duration on the success rate of 6-month smoking cessation.

Methods

This study retrospectively analyzed 78 subjects, who received varenicline, out of the 105 smokers that had visited the smoking cessation clinic after medical examination from September 2007 to December 2009.

Results

The subjects were all males. Twenty-two subjects (28.2%) had varenicline treatment for 12 weeks or longer; 18 subjects (23.1%) for 8~12 weeks; 22 subjects (28.2%) for 4~8 weeks; and 16 subjects (20.5%) for less than 4 weeks. The total success rate of the 6-month smoking cessation was 47.4%. The success rate of the 6-month smoking cessation was 63.6% in the group that received varenicline for 12 weeks or longer, which was higher than 41.1% of the group that early terminated the varenicline treatment (p=0.074). The period of varenicline treatment was extended for one more week, the odds ratio of the 6-month smoking cessation success increased to 1.172-folds (p=0.004; 95% confidence interval, 1.052~1.305). Adverse events occurred in 30.8% of the subjects who received varenicline, but no serious adverse events were found.

Conclusion

If varenicline treatment period is extended, the odds ratio of the success rate for the 6-month smoking cessation increases. Therefore, an effort to improve drug compliance for varenicline in clinical practices could be helpful for the long-term success of smoking cessation.

Introduction:

Varenicline, a first-line non-nicotine medication, has not been evaluated in Black smokers, and limited attention has been paid to pharmacotherapy adherence in smoking cessation trials. This pilot study estimated quit rates for Black smokers treated with varenicline and tested a behavioral intervention to aid varenicline adherence.

Methods:

Seventy-two Black smokers (>10 cigarettes per day; cpd) were randomly assigned to adherence support (AS; n = 36) or standard care (n = 36). All participants received 3 months of varenicline and a single counseling session focused on making a quit plan. AS participants received 5 additional counseling sessions to encourage medication use. Outcome measures included salivary cotinine, and carbon monoxide confirmed smoking abstinence, reductions in self-reported cpd, and pill counts of varenicline adherence at Months 1, 2, and 3.

Results:

Sixty-one participants (84.7%) completed follow-up at Month 3. Participants were female (62.5%), 46.8 years of age, and smoked 16.3 cpd. No treatment group differences were found on the smoking or adherence outcome measures (p > .05). Collapsing across treatment, varenicline adherence was adequate (86.1%), yet despite a reduction of 12.2 (6.5) cpd from baseline to Month 3 (p < 0.001), only 23.6% were confirmed quit at Month 3. Participants who were quit at Month 3 had higher varenicline adherence rates (95.8%) than those who continued to smoke (80.8%, p ≤ .05).

Conclusions:

Studies are needed to examine the efficacy of varenicline among Black smokers. Interventions to facilitate adherence to pharmacotherapy warrant further attention as adherence is linked to improved tobacco abstinence.

Despite efforts to decrease tobacco use, smoking continues to be a leading cause of preventable morbidity and premature death. The associated economic burden is substantial, both in the form of direct costs (healthcare expenditures) and indirect costs (lost productivity), regardless of whether the burden is assessed from the standpoint of an employer, a health plan, or society as a whole. Cessation programs are considered among the most cost-effective in healthcare, and are often used as a benchmark for other medical interventions. This analysis specifically considers the cost-effectiveness of varenicline, a novel α4β2 partial agonist used for smoking cessation, in comparison to other approved therapies. Clinical trial data have demonstrated that varenicline has the ability to decrease cravings and withdrawal symptoms, and lessen positive reinforcement associated with smoking. Varenicline’s novel mechanism has translated into superior efficacy in comparison to other available therapies. For this reason, despite an initial cost that typically exceeds that of other medications, varenicline is a cost-effective option for smoking cessation.

Despite effective therapies for smoking cessation, most smokers find quitting difficult and most successful quitters relapse. Considerable evidence supports a genetic risk for nicotine dependence; however, less is known about the pharmacogenetics of smoking cessation. In the first pharmacogenetic investigation of the efficacy of varenicline and bupropion, we examined whether genes important in the pharmacodynamics and pharmacokinetics of these drugs and nicotine predict medication efficacy and adverse events. Subjects participated in randomized, double-blind, placebo-controlled smoking cessation clinical trials, comparing varenicline, a nicotinic acetylcholine receptor (nAChR) partial agonist, with bupropion, a norepinephrine/dopamine reuptake inhibitor, and placebo. Primary analysis included 1175 smokers of European ancestry, and 785 single nucleotide polymorphisms from 24 genes, representing 254 linkage disequilibrium (LD) bins (genes included nAChR subunits, additional varenicline-specific genes, and genes involved in nicotine or bupropion metabolism). For varenicline, continuous abstinence (weeks 9–12) was associated with multiple nAChR subunit genes (including CHRNB2, CHRNA5, and CHRNA4) (OR=1.76; 95% CI: 1.23–2.52) (p<0.005); for bupropion, abstinence was associated with CYP2B6 (OR=1.78; 95% CI: 1.27–2.50) (p<0.001). Incidence of nausea was associated with several nAChR subunit genes (OR=0.50; 95% CI: 0.36–0.70) (p<0.0001) and time to relapse after quitting was associated with HTR3B (HR=1.97; 95% CI: 1.45–2.68) (p<0.0001). These data provide evidence for multiple genetic loci contributing to smoking cessation and therapeutic response. Different loci are associated with varenicline vs bupropion response, suggesting that additional research may identify clinically useful markers to guide treatment decisions.

Introduction

This review examines the post-marketing experience with varenicline including case reports, newer clinical trials and secondary analyses of large clinical datasets.

Areas Covered

Varenicline has been shown to be an effective treatment in a broad range of tobacco users with medical, behavioral, and diverse demographic characteristics. The recent studies finding excellent safety and efficacy in groups of smokers with diseases including chronic obstructive pulmonary disease are particularly encouraging and call for increased use of this medication for smoking cessation. Despite case reports of serious neuropsychiatric symptoms in patients taking varenicline, including changes in behavior and mood, causality has not been established. Recent analyses of large datasets from clinical trials have not demonstrated that varenicline is associated with more depression or suicidality than other treatments for smoking cessation.

Expert opinion

Now that additional clinical trials in specific populations and observational studies on treatment-seeking smokers outside of clinical trials have been published we can be confident that varenicline remains the most efficacious monotherapy for smoking cessation, and that its side-effect profile remains good. The risk benefit ratio of receiving varenicline to quit smoking must be weighed against the sizeable evidence of premature death in smokers and risk of not taking aggressive action to treat tobacco addiction.