Effectiveness of varenicline for smoking cessation at 2 urban academic health centers

Smoking cessation medicines and e-cigarettes: a systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

Cigarette smoking is one of the leading causes of early death. Varenicline [Champix (UK), Pfizer Europe MA EEIG, Brussels, Belgium; or Chantix (USA), Pfizer Inc., Mission, KS, USA], bupropion (Zyban; GlaxoSmithKline, Brentford, UK) and nicotine replacement therapy are licensed aids for quitting smoking in the UK. Although not licensed, e-cigarettes may also be used in English smoking cessation services. Concerns have been raised about the safety of these medicines and e-cigarettes.

OBJECTIVES

To determine the clinical effectiveness, safety and cost-effectiveness of smoking cessation medicines and e-cigarettes.

DESIGN

Systematic reviews, network meta-analyses and cost-effectiveness analysis informed by the network meta-analysis results.

SETTING

Primary care practices, hospitals, clinics, universities, workplaces, nursing or residential homes.

PARTICIPANTS

Smokers aged ≥ 18 years of all ethnicities using UK-licensed smoking cessation therapies and/or e-cigarettes.

INTERVENTIONS

Varenicline, bupropion and nicotine replacement therapy as monotherapies and in combination treatments at standard, low or high dose, combination nicotine replacement therapy and e-cigarette monotherapies.

MAIN OUTCOME MEASURES

Effectiveness - continuous or sustained abstinence. Safety - serious adverse events, major adverse cardiovascular events and major adverse neuropsychiatric events.

DATA SOURCES

Ten databases, reference lists of relevant research articles and previous reviews. Searches were performed from inception until 16 March 2017 and updated on 19 February 2019.

REVIEW METHODS

Three reviewers screened the search results. Data were extracted and risk of bias was assessed by one reviewer and checked by the other reviewers. Network meta-analyses were conducted for effectiveness and safety outcomes. Cost-effectiveness was evaluated using an amended version of the Benefits of Smoking Cessation on Outcomes model.

RESULTS

Most monotherapies and combination treatments were more effective than placebo at achieving sustained abstinence. Varenicline standard plus nicotine replacement therapy standard (odds ratio 5.75, 95% credible interval 2.27 to 14.90) was ranked first for sustained abstinence, followed by e-cigarette low (odds ratio 3.22, 95% credible interval 0.97 to 12.60), although these estimates have high uncertainty. We found effect modification for counselling and dependence, with a higher proportion of smokers who received counselling achieving sustained abstinence than those who did not receive counselling, and higher odds of sustained abstinence among participants with higher average dependence scores. We found that bupropion standard increased odds of serious adverse events compared with placebo (odds ratio 1.27, 95% credible interval 1.04 to 1.58). There were no differences between interventions in terms of major adverse cardiovascular events. There was evidence of increased odds of major adverse neuropsychiatric events for smokers randomised to varenicline standard compared with those randomised to bupropion standard (odds ratio 1.43, 95% credible interval 1.02 to 2.09). There was a high level of uncertainty about the most cost-effective intervention, although all were cost-effective compared with nicotine replacement therapy low at the £20,000 per quality-adjusted life-year threshold. E-cigarette low appeared to be most cost-effective in the base case, followed by varenicline standard plus nicotine replacement therapy standard. When the impact of major adverse neuropsychiatric events was excluded, varenicline standard plus nicotine replacement therapy standard was most cost-effective, followed by varenicline low plus nicotine replacement therapy standard. When limited to licensed interventions in the UK, nicotine replacement therapy standard was most cost-effective, followed by varenicline standard.

LIMITATIONS

Comparisons between active interventions were informed almost exclusively by indirect evidence. Findings were imprecise because of the small numbers of adverse events identified.

CONCLUSIONS

Combined therapies of medicines are among the most clinically effective, safe and cost-effective treatment options for smokers. Although the combined therapy of nicotine replacement therapy and varenicline at standard doses was the most effective treatment, this is currently unlicensed for use in the UK.

FUTURE WORK

Researchers should examine the use of these treatments alongside counselling and continue investigating the long-term effectiveness and safety of e-cigarettes for smoking cessation compared with active interventions such as nicotine replacement therapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041302.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 59. See the NIHR Journals Library website for further project information.

Healthcare Costs of Smokers Using Varenicline Versus Nicotine-Replacement Therapy Patch in the United States: Evidence from Real-World Practice

INTRODUCTION

Varenicline (VAR) is an effective smoking-cessation therapy compared to the commonly used nicotine-replacement therapy patch (NRT-P). However, comparative real-world evidence on smoking-cessation therapies is limited, especially for economic outcomes.

METHODS

Using national claims databases (2012-2016) in the United States (US), adults initiating VAR or NRT-P without use of any other smoking-cessation products were followed for up to 1 year on a quarterly basis. Outcomes included smoking-attributable (SA) (cardiovascular, diabetes, pulmonary diseases, and smoking cessation) and all-cause costs (2017 US dollars). Adjusted mean costs were estimated from multivariable regressions, with baseline characteristics and propensity scores as covariates. Annual adjusted costs were calculated from quarterly averages.

RESULTS

The VAR cohort (n = 209,284) was younger (mean age 46.7 vs. 49.0 years) and had fewer comorbidities [mean Charlson Comorbidity Index (CCI): 0.8 vs. 1.6] than the NRT-P cohort (n = 34,593). After adjustment, VAR cohort had lower SA and all-cause medical costs than NRT-P cohort in Quarters 1-4 (Q1-Q4) of follow-up, and had lower SA and all-cause total costs in Q2-Q4. Annually, VAR cohort had higher SA total costs ($307) and lower all-cause costs (- $2089) than NRT-P cohort. Annual medical costs were lower in VAR cohort (- $640 for SA and - $2876 for all-cause), and pharmacy costs were higher ($762 for SA and $777 for all-cause). In adherent patients (VAR: n = 38,744; NRT-P: n = 2702), VAR patients had lower annual medical costs (- $794 for SA and - $1636 for all-cause) and higher pharmacy costs ($1175 for SA and $1269 for all-cause); differences in SA and all-cause total costs were not statistically significant between treatment groups.

CONCLUSIONS

Lower SA and all-cause medical costs associated with the use of VAR versus NRT-P resulted in savings in all-cause total costs and, among adherent patients, potentially offset the high pharmacy costs of VAR.

FUNDING

Pfizer, Inc.

Lorcaserin for Smoking Cessation and Associated Weight Gain: A Randomized 12-Week Clinical Trial

Introduction

Lorcaserin is a selective serotonin 2C receptor agonist approved by the Food and Drug Administration for chronic weight management. Preclinical data suggest that it may also be effective in smoking cessation through modulation of the dopaminergic reward system.

Methods

This was a 12-week, randomized, double-blind, placebo-controlled trial conducted in 30 centers in the United States. Six hundred three adult smokers with a Body Mass Index of 18.5-35 kg/m2, averaging at least 10 cigarettes/day with no period of abstinence >3 months for the past year were randomized to lorcaserin 10 mg once daily (QD), 10 mg twice daily (BID) or placebo; all received standardized smoking cessation counseling weekly. The target quit date was day 15. The primary endpoint was the exhaled carbon monoxide confirmed Continuous Abstinence Rate for weeks 9-12 (month 3).

Results

Continuous Abstinence Rates for month 3 were 5.6%, 8.7%, and 15.3% for the placebo, QD and BID groups, respectively (BID vs. placebo odds ratio 3.02, 95% confidence interval 1.47, 6.22, p = .0027. Change in weight at week 12 (randomized population) was -0.01, -0.35 and -0.98 kg, respectively (p = .0004, BID vs. placebo), and +0.73, +0.76, and -0.41 kg in participants achieving month 3 continuous abstinence. The most frequent adverse events were headache, nausea, constipation, and fatigue.

Conclusions

Lorcaserin with counseling was associated with dose-related increases in smoking cessation and prevention of associated weight gain over a 3-month period. Further investigation of lorcaserin in smoking cessation is warranted. Trial Registration: ClinicalTrials.gov. Identifier: NCT02044874.

Implications

This randomized, controlled trial demonstrated that lorcaserin used in conjunction with standard cessation counseling was associated with dose-related increases in smoking cessation and prevention of associated weight gain. To our knowledge, this is the first demonstration in humans of a potential role of 5-HT2C agonism in the modulation of central neurological circuits involved with reward.

Effects of lorcaserin (Belviq®) on nicotine- and food-maintained responding in non-human primates

BACKGROUND

Accumulating evidence suggests that the FDA-approved serotonin 5-HT2C receptor agonist, lorcaserin (Belviq®), may be a promising candidate for the management of substance use disorders, including nicotine addiction. The present study was conducted to determine the efficacy and selectivity of acute or continuous lorcaserin treatment for decreasing the reinforcing effects of nicotine in a primate species.

METHODS

Adult rhesus monkeys (n=4) with a history of nicotine self-administration (>2years) responded for injections of nicotine (0.32-100μg/kg IV) or food pellets under a fixed-ratio schedule of reinforcement during daily 100-min sessions. When responding was stable, lorcaserin was administered either as an acute pretreatment (0.1-1.0mg/kg, IM) or by continuous infusion (0.1mg/kg/hr, SC for 3-5days). Daily activity patterns were also monitored immediately following experimental sessions.

RESULTS

Results indicate that acute lorcaserin pretreatment produced significant and dose-dependent decreases in nicotine-maintained responding across a >100-fold range of self-administered nicotine doses. Continuous lorcaserin treatment decreased intake of 10μg/kg/inj nicotine to about 50% of baseline values. Food-maintained responding was only moderately decreased in 3 of 4 subjects after acute administration and unaffected in all subjects during continuous treatment. Daily activity also was significantly decreased-to ≤50% of control values-following experimental sessions in which acute lorcaserin was administered.

CONCLUSIONS

These data indicate that lorcaserin reduces IV self-administration of nicotine at a dose that decreases motoric activity but less consistently disrupts food-maintained responding. Further research into lorcaserin's potential utility for the management of nicotine dependence is warranted.

Effectiveness of varenicline and counselling for smoking cessation in an observational cohort study in China

OBJECTIVES

To evaluate the effectiveness of varenicline for smoking cessation in Chinese smokers in a real world cessation clinic practice.

DESIGN

A prospective observational study.

SETTING

Beijing, China.

PARTICIPANTS

A total of 924 smokers (883 men and 41 women) who attended a smoking cessation clinic of a large general hospital were assessed with data from structured questionnaires at baseline and follow-up at 1, 3 and 6 months. Trained physician counsellors provided free individual counselling for all subjects and follow-up interviews with brief counselling. 332 subjects additionally prescribed varenicline according to their own choice were compared with those without varenicline.

MAIN OUTCOME MEASURES

Primary outcomes were self-reported 7-day point prevalence abstinence rate and 3-month continuous abstinence rate at 6-month follow-up. Secondary outcomes were 7-day point prevalence abstinence rates at 1 and 3-month follow-up, and 1-month continuous abstinence rate at 3-month follow-up.

RESULTS

By intention-to-treat, the 7-day point prevalence abstinence rate with varenicline and counselling at 6 months was significantly higher than counselling only (37.0% vs 23.1%; OR, 1.75; 95% CI 1.46 to 2.62; p=0.001). The 3-month continuous abstinence rate at 6 months was higher with varenicline (33.1% vs 18.4%; OR, 2.04; 95% CI 1.61 to 2.99; p<0.001). Varenicline also showed better secondary outcomes.

CONCLUSIONS

Varenicline prescription in the smoking cessation clinic appeared to be effective with doubling of quit rates in Chinese smokers in a real world cessation clinic practice.

CLINICAL TRIAL REGISTRATION

NCT01935505; Results.

Mental health status of varenicline and bupropion users during a quit attempt compared to current smokers, other quitters, and non-smokers

BACKGROUND

Varenicline and bupropion are commonly prescribed non-nicotine containing smoking cessation agents. Post-marketing reports suggest an increased incidence of psychiatric disturbances associated with varenicline and bupropion. However, pre-existing psychiatric disorders may confound the association between these smoking cessation agents and psychiatric disturbances. We compared the mental health status of individuals using varenicline or bupropion to that of people quitting without medication, current smokers, and non-smokers while controlling for pre-existing conditions.

METHODS

A cross-sectional design was used. Data were from 2006-2011 Medical Expenditure Panel Survey. Mental health status was assessed using the mental component summary (MCS) from the 12-item Short Form survey (SF-12v2), 2-item Patient Health Questionnaire (PHQ-2), and Kessler 6 Scale (K6). Differences in MCS score were compared using linear regression. Logistic regressions were used to compare positive screenings for depression using PHQ-2 and for psychological distress using K6.

RESULTS

Of 578 use episodes, 453 (78.38%) were bupropion and 125 (21.62%) were varenicline. After adjusting for potential confounders, mental health status of varenicline users was not different from current smokers or people who quit smoking without medication, but worse than non-smokers; bupropion was strongly associated with lower mental health status relative to all groups across all three measures.

CONCLUSION

Varenicline was not associated with worse mental health compared to smokers or those who quit without medication, after adjusting for pre-existing psychiatric disorders. Bupropion was associated with worse mental health status than smokers, former smokers who quit without medication, and nonsmokers, even after adjusting for pre-existing psychiatric disorders.

Prospective cohort study of the effectiveness of varenicline versus nicotine replacement therapy for smoking cessation in the "real world"

Background

It is important to know the comparative effectiveness of varenicline and nicotine replacement therapy (NRT) for smoking cessation when prescribed under routine circumstances and in the general population. Previous estimates relied on cross-sectional data. The objective of the current study was to use longitudinal data to compare the abstinence rates of smokers trying to stop having used varenicline versus NRT on prescription (Rx) when provided with minimal professional support in the general population while adjusting for key potential confounders.

Methods

Prospective cohort study in 270 adults who participated in a household survey, smoked at baseline, responded to the 6-month follow-up survey, and made at least one quit attempt between the two measurements with either varenicline or NRT Rx in their most recent quit attempt. The main outcome measure was self-reported abstinence up to the time of the survey, adjusted for key potential confounders including cigarette dependence (measured at baseline).

Results

Users of varenicline were younger, reported more time spent with urges to smoke at baseline, and were less likely to stop abruptly during their last quit attempt (all p < 0.01). The adjusted odds of abstinence in users of varenicline were 3.83 (95% CI = 1.88-7.77) times higher compared with users of NRT Rx.

Conclusions

Varenicline use with minimal professional support in the general population of smokers appears more effective than NRT Rx in achieving abstinence.

Effectiveness of the electronic cigarette: An eight-week Flemish study with six-month follow-up on smoking reduction, craving and experienced benefits and complaints

Background: Smoking reduction remains a pivotal issue in public health policy, but quit rates obtained with traditional quit-smoking therapies remain disappointingly low. Tobacco Harm Reduction (THR), aiming at less harmful ways of consuming nicotine, may provide a more effective alternative. One promising candidate for THR are electronic cigarettes (e-cigs). The aim of this study was to investigate the efficacy of second-generation e-cigs both in terms of acute craving-reduction in the lab and in terms of smoking reduction and experienced benefits/complaints in an eight-month Randomized Controlled Trial (RCT). Design: RCT with three arms. Methods: Participants (N = 48) unwilling to quit smoking were randomized into two e-cig groups and one control group. During three lab sessions (over two months) participants, who had been abstinent for four hours, vaped/smoked for five minutes, after which we monitored the effect on craving and withdrawal symptoms. eCO and saliva cotinine levels were also measured. In between lab sessions, participants in the e-cig groups could use e-cigs or smoke ad libitum, whereas the control group could only smoke. After the lab sessions, the control group also received an e-cig. The RCT included several questionnaires, which repeatedly monitored the effect of ad libitum e-cig use on the use of tobacco cigarettes and the experienced benefits/complaints up to six months after the last lab session. Results: From the first lab session on, e-cig use after four hours of abstinence resulted in a reduction in cigarette craving which was of the same magnitude as when a cigarette was smoked, while eCO was unaffected. After two months, we observed that 34% of the e-cig groups had stopped smoking tobacco cigarettes, versus 0% of the control group (difference p < 0.01). After five months, the e-cig groups demonstrated a total quit-rate of 37%, whereas the control group showed a quit rate of 38% three months after initiating e-cig use. At the end of the eight-month study, 19% of the e-cig groups and 25% of the control group were totally abstinent from smoking, while an overall reduction of 60% in the number of cigarettes smoked per day was observed (compared to intake). eCO levels decreased, whereas cotinine levels were the same in all groups at each moment of measurement. Reported benefits far outweighed the reported complaints. Conclusion: In a series of controlled lab sessions with e-cig naïve tobacco smokers, second generation e-cigs were shown to be immediately and highly effective in reducing abstinence induced cigarette craving and withdrawal symptoms, while not resulting in increases in eCO. Remarkable (>50 pc) eight-month reductions in, or complete abstinence from tobacco smoking was achieved with the e-cig in almost half (44%) of the participants.

Effectiveness of varenicline versus nicotine replacement therapy for smoking cessation with minimal professional support: evidence from an English population study

RATIONALE

Limited evidence from randomised controlled trials suggests that varenicline might be more effective than nicotine replacement therapy (NRT) in achieving abstinence from smoking. The comparative effectiveness of varenicline when prescribed under routine circumstances and in the general population has not been tested.

OBJECTIVES

To compare the abstinence rates of smokers trying to stop having used varenicline vs. NRT on prescription (Rx) when provided with minimal professional support in the general population while adjusting for key potential confounders.

METHODS

A large survey of a representative sample of the English population. Participants were 1,579 adults who smoked within the previous 12 months and made at least one quit attempt with varenicline or NRT Rx in their most recent quit attempt. The main outcome measure was self-reported abstinence up to the time of the survey, adjusted for key potential confounders including urges to smoke. A sensitivity analysis was conducted in subsamples in which the quit attempt started up to 6 months or more than 6 months ago.

RESULTS

The adjusted odds of abstinence in users of varenicline were 1.76 (95 % CI = 1.22-2.53) times higher compared with users of NRT Rx. However, there was no detectable difference in the subsample of smokers who started their quit attempt more than 6 months ago (adjusted OR = 1.03, 95 %CI = 0.54-1.96).

CONCLUSIONS

Varenicline use with minimal professional support in the general population of smokers appears more effective than NRT Rx in achieving short-term abstinence. However, this effect may disappear in the long-term. Research is needed to confirm this and establish what may underlie it.

Varenicline for smoking cessation among methadone-maintained smokers: a randomized clinical trial

BACKGROUND

With smoking rates far exceeding the general population, methadone-maintained (MMT) opiate-dependent smokers experience high rates of tobacco-related health consequences. Previous treatment studies have used nicotine replacement and produced low quit rates.

METHODS

We test, using a three-group randomized design, the efficacy of varenicline versus placebo, in comparison with nicotine replacement therapy (NRT) that combines nicotine patch prescription plus ad libitum nicotine rescue, for smoking cessation. We recruited methadone-maintained smokers from nine treatment centers in southern New England and provided six months of treatment, and a minimal behavioral intervention at baseline (NCI's 5A's). Outcomes included carbon monoxide (CO) confirmed 7-day point smoking cessation prevalence at 6 months and self-reported change in mean cigarettes per day.

RESULTS

The 315 participants had a mean age of 40, with 50% male and 79% non-Hispanic White, smoked an average of 19.6 (± 10.4) cigarettes/day, and had a mean daily methadone dose of 109 mg. Intent-to-treat analyses, with missing considered to be smoking, showed the rate of CO-confirmed 7-day abstinence at 6-months was 5.4% overall, with varenicline 3.7% compared to placebo 2.2%, and NRT 8.3% (p>.05). Adherence rates during the 7-days immediately prior to 6-month assessment were 34.2% in varenicline, 34.4% in placebo, and 48.8% in NRT. Between baseline and 6-months there was an overall self-reported mean reduction of 8.3 cigarettes/day.

CONCLUSION

Varenicline did not increase quit rates over placebo. Smoking cessation rates in methadone-maintained smokers are low and novel treatment strategies are required.

Long-term nicotine treatment down-regulates α6β2* nicotinic receptor expression and function in nucleus accumbens

Long-term nicotine exposure induces alterations in dopamine transmission in nucleus accumbens that sustain the reinforcing effects of smoking. One approach to understand the adaptive changes that arise involves measurement of endogenous dopamine release using voltammetry. We therefore treated rats for 2-3 months with nicotine and examined alterations in nAChR subtype expression and electrically evoked dopamine release in rat nucleus accumbens shell, a region key in addiction. Long-term nicotine treatment selectively decreased stimulated α6β2* nAChR-mediated dopamine release compared with vehicle-treated rats. It also reduced α6β2* nAChRs, suggesting the receptor decline may contribute to the functional loss. This decreased response in release after chronic nicotine treatment was still partially sensitive to the agonist nicotine. Studies with an acetylcholinesterase inhibitor demonstrated that the response was also sensitive to increased endogenous acetylcholine. However, unlike the agonists, nAChR antagonists decreased dopamine release only in vehicle- but not nicotine-treated rats. As antagonists function by blocking the action of acetylcholine, their ineffectiveness suggests that reduced acetylcholine levels partly underlie the dampened α6β2* nAChR-mediated function in nicotine-treated rats. As long-term nicotine modifies dopamine release by decreasing α6β2* nAChRs and their function, these data suggest that interventions that target this subtype may be useful for treating nicotine dependence. Long-term nicotine treatment decreases dopamine (DA) transmission in the mesolimbic dopaminergic system. Our data suggest this may involve a decrease in α6β2* nicotinic receptor expression and function. These changes may play a key role in nicotine reward and dependence.