Risk of serious adverse cardiovascular events associated with varenicline: a systematic review and meta-analysis

Definition of Best Medical Treatment in Asymptomatic and Symptomatic Carotid Artery Stenosis

Implementation of best medical treatment (BMT) is the cornerstone of the management of patients with either asymptomatic or symptomatic carotid artery stenosis. We review the literature to define the components of BMT. Smoking cessation, maintaining a healthy body weight, moderate exercise, and a Mediterranean diet are essential lifestyle measures. Moderate alcohol consumption may also be beneficial but recommending it to patients may be hazardous if they consume too much. The importance of lifestyle measures is largely underestimated by both physicians and patients. Blood pressure and diabetes control, antiplatelet agents, and lipid-lowering treatment with statins/ezetimibe comprise the pharmacological components of BMT. Initiation of an intensive regimen of BMT is a sine qua non for patients with carotid artery stenosis whether or not they are offered or undergo an invasive revascularization procedure.

HIV and smoking: associated risks and prevention strategies

High rates of smoking among persons living with HIV (PLWH) may reduce the effectiveness of HIV treatment and contribute to significant morbidity and mortality. Factors associated with smoking in PLWH include mental health comorbidity, alcohol and drug use, health-related quality of life, smoking among social networks and supports, and lack of access to care. PLWH smokers are at a higher risk of numerous HIV-associated infections and non-HIV related morbidity, including a decreased response to antiretroviral treatment, impaired immune functioning, reduced cognitive functioning, decreased lung functioning, and cardiovascular disease. Seventeen smoking cessation interventions were identified, of which seven were randomized controlled trials. The most effective studies combined behavioral and pharmacotherapy treatments that incorporated comprehensive assessments, multiple sessions, and cognitive-behavioral and motivational strategies. Smoking cessation interventions that are tailored to the unique needs of diverse samples and incorporate strategies to reduce the risk of relapse are essential to advancing health outcomes in PLWH.

What are the effects of varenicline compared with nicotine replacement therapy on long-term smoking cessation and clinically important outcomes? Protocol for a prospective cohort study

INTRODUCTION

Smoking is a major avoidable cause of ill-health and premature death. Treatments that help patients successfully quit smoking have an important effect on health and life expectancy. Varenicline is a medication that can help smokers successfully quit smoking. However, there are concerns that it may cause adverse effects, such as increase in the occurrence of depression, self-harm and suicide and cardiovascular disease. In this study we aim to examine the effects of varenicline versus other smoking cessation pharmacotherapies on smoking cessation, health service use, all-cause and cause-specific mortality and physical and mental health conditions.

METHODS

In this project we will investigate the effects of varenicline compared to nicotine replacement therapies on: (1) long-term smoking cessation and whether these effects differ by area level deprivation; and (2) the following clinically-important outcomes: rate of general practice and hospital attendance; all-cause mortality and death due to diseases of the respiratory system and cardiovascular disease; and a primary care diagnosis of respiratory illness, myocardial infarction or depression and anxiety. The study is based on a cohort of patients prescribed these smoking cessation medications from the Clinical Practice Research Datalink (CPRD). We will use three methods to overcome confounding: multivariable adjusted Cox regression, propensity score matched Cox regression, and instrumental variable regression. The total expected sample size for analysis will be at least 180,000. Follow-up will end with the earliest of either an 'event' or censoring due to the end of registration or death.

ETHICS AND DISSEMINATION

Ethics approval was not required for this study. This project has been approved by the CPRD's Independent Scientific Advisory Committee (ISAC). We will disseminate our findings via publications in international peer-reviewed journals and presentations at international conferences.

Evaluation of the cardiovascular effects of varenicline in rats

BACKGROUND

Cardiovascular disease is an important cause of morbidity and mortality among tobacco users. Varenicline is widely used worldwide to help smoking cessation, but some published studies have reported associated cardiovascular events.

OBJECTIVE

To determine the cardiovascular toxicity induced by varenicline in rats.

MATERIALS AND METHODS

We randomly separated 34 rats into two groups: 1) the control group (given only distilled water orally, n=10) and the varenicline group (given 9 μg/kg/day varenicline on days 1-3, 9 μg/kg twice daily on days 4-7, and 18 μg/kg twice daily on days 8-90 [total 83 days], n=24). Each group was then subdivided equally into acute and chronic subgroups, and all rats in these groups were euthanized with anesthesia overdose on days 45 and 90, respectively. Body and heart weights, hemodynamic (mean oxygen saturation, mean blood pressure, and heart rate, electrocardiographic (PR, QRS, and QT intervals) biochemical (oxidants and antioxidants), and histopathological analyses (including immunostaining) were performed.

RESULTS

Acute varenicline exposure resulted in loss of body weight, while chronic varenicline exposure caused heart weight loss and decreased mean blood pressure, induced lipid peroxidation, and reduced antioxidant activity. Both acute and chronic varenicline exposure caused impairment of mean oxygen saturation. QT interval was prolonged in the chronic varenicline group, while PR interval prolongation was statistically significant in both the control and acute varenicline groups. Caspase-9 activity was also significantly increased by chronic exposure. Moreover, histopathological observations revealed severe morphological heart damage in both groups.

CONCLUSION

Adverse effects of chronic varenicline exposure on cardiovascular tissue were confirmed by our electrocardiographic, biochemical, and histopathological analyses. This issue needs to be investigated with new experimental and clinical studies to evaluate the exact mechanism(s) of the detrimental effects of varenicline. Physicians should bear in mind the toxic effects of varenicline on the cardiovascular system when prescribing it for smoking cessation.

A randomized controlled trial of the efficacy and safety of varenicline for smoking cessation after acute coronary syndrome: design and methods of the Evaluation of Varenicline in Smoking Cessation for Patients Post-Acute Coronary Syndrome trial

Patients who continue to smoke after an acute coronary syndrome (ACS) have a significantly increased risk of reinfarction and death compared with those who quit. Varenicline is a first-line smoking cessation therapy with proven efficacy in the general population. However, its efficacy and safety immediately after an ACS are unknown.

METHODS

The EVITA trial is a multicenter, double-blind, randomized, placebo-controlled trial (NCT00794573). The primary objective is to evaluate the efficacy of varenicline after ACS in achieving biochemically validated smoking abstinence at 24 weeks. The secondary objectives are to examine the efficacy of varenicline for smoking abstinence and reduction in daily cigarette consumption at 52 weeks and to describe the occurrence of adverse events. Three hundred and two patients motivated to quit smoking were enrolled in the United States and Canada from November 2009 to December 2014 while hospitalized with an ACS. These participants were randomized (1:1) to either varenicline (1.0 mg twice daily) or placebo for 12 weeks. The trial includes follow-ups by telephone at weeks 1, 2, and 8 and clinic visits at weeks 4, 12, 24, and 52. Data collected include demographic and clinical characteristics, self-reported smoking, exhaled carbon monoxide (an indicator of current smoking), and adverse events.

CONCLUSION

The EVITA trial will provide novel information concerning the efficacy and safety of varenicline immediately after ACS. If varenicline is efficacious in this population, it will have a major impact on secondary prevention of recurrent clinical events in patients post-ACS.

Cardiovascular and neuropsychiatric risks of varenicline: a retrospective cohort study

Background

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.

Methods

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).

Findings

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]).

Interpretation

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.

Funding

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.

The Past, Present, and Future of Nicotine Addiction Therapy

The tobacco addiction treatment field is progressing through innovations in medication development, a focus on precision medicine, and application of new technologies for delivering support in real time and over time. This article reviews the evidence for combined and extended cessation pharmacotherapy and behavioral strategies including provider advice, individual counseling, group programs, the national quitline, websites and social media, and incentives. Healthcare policies are changing to offer cessation treatment to the broad population of smokers. With knowledge of the past and present, this review anticipates what is likely on the horizon in the clinical and public health effort to address tobacco addiction.

Effect of Smoking Reduction Therapy on Smoking Cessation for Smokers without an Intention to Quit: An Updated Systematic Review and Meta-Analysis of Randomized Controlled

OBJECTIVE

Effective strategies are needed to encourage smoking cessation for smokers without an intention to quit. We systematically reviewed the literature to investigate whether smoking reduction therapy can increase the long-term cessation rates of smokers without an intention to quit.

METHODS

PubMed, Embase, and CENTRAL (Cochrane Central Register of Controlled Trials) were searched for randomized controlled trials (RCTs) on the effect of smoking reduction therapy on long-term smoking cessation in smokers without an intention to quit. The primary outcome was the cessation rate at the longest follow-up period. A random effects model was used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

Fourteen trials with a total of 7981 smokers were included. The pooled analysis suggested that reduction support plus medication significantly increased the long-term cessation of smokers without an intention to quit compared to reduction support plus placebo (RR, 1.97; 95% CI, 1.44-2.7; I(2), 52%) or no intervention (RR, 1.93; 95% CI, 1.41-2.64; I(2), 46%). In a subgroup of smokers who received varenicline or nicotine replacement therapy (NRT), the differences were also statistically significant. This suggests the safety of using NRT. The percentage of smokers with serious adverse events who discontinued because of these events in the non-NRT group was slightly significantly different than in the control group. Insufficient evidence is available to test the efficacy of reduction behavioural support in promoting long-term cessation among this population.

CONCLUSIONS

The present meta-analysis indicated the efficacy of NRT- and varenicline-assisted reduction to achieve complete cessation among smokers without an intention to quit. Further evidence is needed to assess the efficacy and safety of reduction behavioural support and bupropion.

Eficacia y seguridad del uso de medicamentos para la cesación de la adicción al tabaco: revisión de guías de práctica clínica

<p><strong>Objetivo </strong>Revisar la eficacia y seguridad de medicamentos para cesación del tabaquismo en el contexto de construcción de guías de práctica clínica (GPC).</p><p><strong>Métodos</strong> Revisión sistemática de GPC para adaptación mediante ADAPTE. Los desenlaces fueron cesación ≥6 meses y seguridad de las intervenciones. Las GPC se calificaron por pares con DELBI. Se extrajeron resultados de estudios agregativos incluidos en las guías seleccionadas.</p><p><strong>Resultados </strong>Los fármacos duplican la cesación comparados con placebo (tasas de 25,0 % hasta 27,0 % al combinarse con consejería). Los mayores incrementos en cesación se obtienen con ansiolíticos y antidepresivos (8,7% a 19,4%), y los menores con terapia de reemplazo nicotínico –TRN- (5,2% a 12,9%). La nortriptilina tiene eficacia similar al bupropion (aproximadamente 10,0 %). Con limitadas excepciones (parche e inhalador, tabletas y bupropion), las combinaciones de medicamentos no incrementan la abstinencia.</p><p><strong>Conclusiones </strong>TRN, vareniclina, bupropion y nortriptilina son eficaces para dejar de fumar. Las combinaciones de medicamentos requieren más evidencia y deberían restringirse a personas con alta dependencia o con falla terapéutica inicial. Serían deseables análisis de costo-efectividad para valorar implementación de programas en países en desarrollo.</p>

Psychosocial interventions for smoking cessation in patients with coronary heart disease

BACKGROUND

This is an update of a Cochrane review previously published in 2008. Smoking increases the risk of developing atherosclerosis but also acute thrombotic events. Quitting smoking is potentially the most effective secondary prevention measure and improves prognosis after a cardiac event, but more than half of the patients continue to smoke, and improved cessation aids are urgently required.

OBJECTIVES

This review aimed to examine the efficacy of psychosocial interventions for smoking cessation in patients with coronary heart disease in short-term (6 to 12 month follow-up) and long-term (more than 12 months). Moderators of treatment effects (i.e. intervention types, treatment dose, methodological criteria) were used for stratification.

SEARCH METHODS

The Cochrane Central Register of Controlled Trials (Issue 12, 2012), MEDLINE, EMBASE, PsycINFO and PSYNDEX were searched from the start of the database to January 2013. This is an update of the initial search in 2003. Results were supplemented by cross-checking references, and handsearches in selected journals and systematic reviews. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in patients with CHD with a minimum follow-up of 6 months.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and risk of bias. Abstinence rates were computed according to an intention to treat analysis if possible, or if not according to completer analysis results only. Subgroups of specific intervention strategies were analysed separately. The impact of study quality on efficacy was studied in a moderator analysis. Risk ratios (RR) were pooled using the Mantel-Haenszel and random-effects model with 95% confidence intervals (CI).

MAIN RESULTS

We found 40 RCTs meeting inclusion criteria in total (21 trials were new in this update, 5 new trials contributed to long-term results (more than 12 months)). Interventions consist of behavioural therapeutic approaches, telephone support and self-help material and were either focused on smoking cessation alone or addressed several risk factors (eg. obesity, inactivity and smoking). The trials mostly included older male patients with CHD, predominantly myocardial infarction (MI). After an initial selection of studies three trials with implausible large effects of RR > 5 which contributed to substantial heterogeneity were excluded. Overall there was a positive effect of interventions on abstinence after 6 to 12 months (risk ratio (RR) 1.22, 95% confidence interval (CI) 1.13 to 1.32, I² 54%; abstinence rate treatment group = 46%, abstinence rate control group 37.4%), but heterogeneity between trials was substantial. Studies with validated assessment of smoking status at follow-up had similar efficacy (RR 1.22, 95% CI 1.07 to 1.39) to non-validated trials (RR 1.23, 95% CI 1.12 to 1.35). Studies were stratified by intervention strategy and intensity of the intervention. Clustering reduced heterogeneity, although many trials used more than one type of intervention. The RRs for different strategies were similar (behavioural therapies RR 1.23, 95% CI 1.12 to 1.34, I² 40%; telephone support RR 1.21, 95% CI 1.12 to 1.30, I² 44%; self-help RR 1.22, 95% CI 1.12 to 1.33, I² 40%). More intense interventions (any initial contact plus follow-up over one month) showed increased quit rates (RR 1.28, 95% CI 1.17 to 1.40, I² 58%) whereas brief interventions (either one single initial contact lasting less than an hour with no follow-up, one or more contacts in total over an hour with no follow-up or any initial contact plus follow-up of less than one months) did not appear effective (RR 1.01, 95% CI 0.91 to 1.12, I² 0%). Seven trials had long-term follow-up (over 12 months), and did not show any benefits. Adverse side effects were not reported in any trial. These findings are based on studies with rather low risk of selection bias but high risk of detection bias (namely unblinded or non validated assessment of smoking status).

AUTHORS' CONCLUSIONS

Psychosocial smoking cessation interventions are effective in promoting abstinence up to 1 year, provided they are of sufficient duration. After one year, the studies showed favourable effects of smoking cessation intervention, but more studies including cost-effectiveness analyses are needed. Further studies should also analyse the additional benefit of a psychosocial intervention strategy to pharmacological therapy (e.g. nicotine replacement therapy) compared with pharmacological treatment alone and investigate economic outcomes.

Identification and in vitro pharmacological characterization of a novel and selective α7 nicotinic acetylcholine receptor agonist, Br-IQ17B

Aim:

Alpha7-nicotinic acetylcholine receptor (α7 nAChR) is a ligand-gated Ca²⁺-permeable ion channel implicated in cognition and neuropsychiatric disorders. Activation of α7 nAChR improves learning, memory, and sensory gating in animal models. To identify novel α7 nAChR agonists, we synthesized a series of small molecules and characterized a representative compound, Br-IQ17B, N-[(3R)-1-azabicyclo[2,2,2]oct-3-yl]-5-bromoindolizine-2-carboxamide, which specifically activates α7 nAChR.

Methods:

Two-electrode voltage clamp (TEVC) recordings were primarily used for screening in Xenopus oocytes expressing human α7 nAChR. Assays, including radioisotope ligand binding, Western blots, whole-cell recordings of hippocampal culture neurons, and spontaneous IPSC recordings of brain slices, were also utilized to evaluate and confirm the specific activation of α7 nAChR by Br-IQ17B.

Results:

Br-IQ17B potently activates α7 nAChR with an EC₅₀ of 1.8±0.2 μmol/L. Br-IQ17B is selective over other subtypes such as α4β2 and α3β4, but it blocks 5-HT_3A receptors. Br-IQ17B displaced binding of the α7 blocker [³H]-MLA to hippocampal crude membranes with a K_i of 14.9±3.2 nmol/L. In hippocampal neurons, Br-IQ17B evoked α7-like currents that were inhibited by MLA and enhanced in the presence of the α7 PAM PNU-120596. In brain slice recordings, Br-IQ17B enhanced GABAergic synaptic transmission in CA1 neurons. Mechanistically, Br-IQ17B increased ERK1/2 phosphorylation that was MLA-sensitive.

Conclusion:

We identified the novel, potent, and selective α7 agonist Br-IQ17B, which enhances synaptic transmission. Br-IQ17B may be a helpful tool to understand new aspects of α7 nAChR function, and it also has potential for being developed as therapy for schizophrenia and cognitive deficits.

Big biomedical data and cardiovascular disease research: opportunities and challenges

Electronic health records (EHRs), data generated and collected during normal clinical care, are increasingly being linked and used for translational cardiovascular disease research. Electronic health record data can be structured (e.g. coded diagnoses) or unstructured (e.g. clinical notes) and increasingly encapsulate medical imaging, genomic and patient-generated information. Large-scale EHR linkages enable researchers to conduct high-resolution observational and interventional clinical research at an unprecedented scale. A significant amount of preparatory work and research, however, is required to identify, obtain, and transform raw EHR data into research-ready variables that can be statistically analysed. This study critically reviews the opportunities and challenges that EHR data present in the field of cardiovascular disease clinical research and provides a series of recommendations for advancing and facilitating EHR research.

Design strategy for a smoking cessation trial of survival

Despite unequivocal evidence that smoking cessation is beneficial in terms of survival, there is at present no firm evidence that smoking cessation programs save lives. While they do increase quit rates, the collective evidence from randomized trials is inconclusive with respect to long-term survival. Withdrawal symptoms and the potential for harm when a subjects relapses after a prolonged period of cessation (e.g., 5+ years) might mitigate some or all of the benefits of the sustained quitters. This paper will review the key survival epidemiology and argue for a large randomized field trial of about 30,000 subjects, followed personally for 5 years and collectively for 15 years through the National Death Index. The intervention should be personalized, but reproducible through a treatment assignment algorithm. Personal coaching should be a major part of the intervention. Important short-term data on healthcare utilization should also be collected. Strong financial motivation for quitting (or prevention of smoking in the first place) is also presented. This paper is intended to motivate a large collective effort amongst the US Clinical and Translational Science Awardees to design the intervention and bring together the interested players to conduct the study.

Smoking cessation in Asians: focus on varenicline

Smoking is a modifiable risk factor for morbidity and mortality caused by cancer, cardiovascular diseases, respiratory diseases, and many other diseases. Given the large population size and high prevalence of smoking in Asia, successful smoking cessation could potentially prevent the large number of premature deaths in Asians. However, most dependent smokers cannot successfully quit smoking due to nicotine addiction, and they need professional help and smoking cessation therapies. Varenicline is a highly selective partial agonist for the nicotinic acetylcholine receptor α4β2 subtype, which is believed to be responsible for mediating the reinforcing properties of nicotine. This article is a narrative review, which summarizes the smoking cessation efficacy, side effects, and cost utilities of varenicline in Asians. From this review, we conclude that varenicline is an effective medication that could assist smoking cessation in the Asian populations. The adverse events of varenicline are tolerable, and the most common events were nausea and abnormal dreams. Both the efficacy and tolerance of varenicline in Asians are similar to that in Western populations. Considering the cost utilities, varenicline should be recommended for use in smoking cessation and be covered by medical insurance in most Asian countries.

Cardiovascular Safety Outcome Trials: A meeting report from the Cardiac Safety Research Consortium

This White Paper provides a summary of presentations and discussions at a Cardiovascular Safety Outcome Trials Think Tank cosponsored by the Cardiac Safety Research Consortium, the US Food and Drug Administration, and the American College of Cardiology, held at American College of Cardiology's Heart House, Washington, DC, on February 19, 2014. Studies to assess cardiovascular (CV) risk of a new drug are sometimes requested by regulators to resolve ambiguous safety signals seen during its development or among other members of its class. Think Tank participants thought that important considerations in undertaking such studies were as follows: (1) plausibility-how likely it is that a possible signal indicating risk is real, based on strength of evidence, and/or whether a plausible mechanism of action for potential CV harm has been identified; (2) relevance-what relative and absolute CV risk would need to be excluded to determine that the drug had an acceptable benefit-to-risk balance for its use in the intended patient population; and (3) how plausibility and relevance influence the timing and approach to further safety assessment.

Nephrotoxic effects of varenicline as the most effective drug used for smoking cessation: a preliminary experimental study

PURPOSE

Varenicline is a new most effective drug for smoking cessation. Its effect on kidney functions remains unclear. This study purposed to investigate whether varenicline causes nephrotoxicity in rats.

METHODS

Fifteen rats were randomly assigned to three groups: control, 0.0125 mg kg(-1) varenicline and 0.025 mg kg(-1) varenicline (single dose for 3 days, i.p.). Before and after experimental period, serum neutrophil gelatinase-associated lipocalin, creatinine and urea levels were measured. Total oxidant and antioxidant status were measured in kidney homogenates. Histological examination was performed in kidney.

RESULTS

The nephrotoxic effects of varenicline were detected by histopathological and biochemical examinations in the varenicline treatment groups. No change was observed in the control group.

CONCLUSIONS

These findings firstly indicate that a 3-day varenicline treatment causes nephrotoxic effects in rats.

Risk of neuropsychiatric adverse events associated with varenicline: systematic review and meta-analysis

OBJECTIVE

To determine the risk of neuropsychiatric adverse events associated with use of varenicline compared with placebo in randomised controlled trials.

DESIGN

Systematic review and meta-analysis comparing study effects using two summary estimates in fixed effects models, risk differences, and Peto odds ratios.

DATA SOURCES

Medline, Embase, PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL), and clinicaltrials.gov.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials with a placebo comparison group that reported on neuropsychiatric adverse events (depression, suicidal ideation, suicide attempt, suicide, insomnia, sleep disorders, abnormal dreams, somnolence, fatigue, anxiety) and death. Studies that did not involve human participants, did not use the maximum recommended dose of varenicline (1 mg twice daily), and were cross over trials were excluded.

RESULTS

In the 39 randomised controlled trials (10,761 participants), there was no evidence of an increased risk of suicide or attempted suicide (odds ratio 1.67, 95% confidence interval 0.33 to 8.57), suicidal ideation (0.58, 0.28 to 1.20), depression (0.96, 0.75 to 1.22), irritability (0.98, 0.81 to 1.17), aggression (0.91, 0.52 to 1.59), or death (1.05, 0.47 to 2.38) in the varenicline users compared with placebo users. Varenicline was associated with an increased risk of sleep disorders (1.63, 1.29 to 2.07), insomnia (1.56, 1.36 to 1.78), abnormal dreams (2.38, 2.05 to 2.77), and fatigue (1.28, 1.06 to 1.55) but a reduced risk of anxiety (0.75, 0.61 to 0.93). Similar findings were observed when risk differences were reported. There was no evidence for a variation in depression and suicidal ideation by age group, sex, ethnicity, smoking status, presence or absence of psychiatric illness, and type of study sponsor (that is, pharmaceutical industry or other).

CONCLUSIONS

This meta-analysis found no evidence of an increased risk of suicide or attempted suicide, suicidal ideation, depression, or death with varenicline. These findings provide some reassurance for users and prescribers regarding the neuropsychiatric safety of varenicline. There was evidence that varenicline was associated with a higher risk of sleep problems such as insomnia and abnormal dreams. These side effects, however, are already well recognised.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2014:CRD42014009224.

Extended varenicline treatment in a severe cardiopathic cigarette smoker: a case report

INTRODUCTION

Tobacco smoking is the leading cause of cardiovascular morbidity and mortality and quitting tobacco use should be fundamental for cardiovascular patients. Varenicline is a smoking cessation pharmacological therapy able to improve the possibilities to successfully achieve this result. In 2011 the US Food and Drug Administration issued a safety announcement that varenicline may be associated with an increased risk of certain cardiovascular adverse events in patients who have cardiovascular disease. Following studies found no significant increase in cardiovascular serious adverse events associated with varenicline. For the first time in the literature, we describe the case of a cardiopathic hard smoker who received varenicline for 9 months without any side effect. By describing this case we want to underline the safety of varenicline, to illustrate the setting and the method that we used to support him and to underline the importance of promoting smoking cessation in heart patients.

CASE PRESENTATION

Varenicline was used to promote smoking cessation in a 52-year-old Caucasian man who smoked 40 cigarettes per day, despite two ischemic cardiovascular events. He asked for a consultation in a pharmacy's smoking cessation service and after the assessment phase varenicline was prescribed. Due to his difficulty to quit smoking and given his good tolerance of the drug, we extended the treatment with varenicline to 9 months in order to achieve and maintain a complete smoking abstinence; intensive behavioural counselling was combined with the pharmacological therapy. By using exhaled carbon monoxide measurement we assessed smoking abstinence up to 2 years.

CONCLUSIONS

The use of varenicline for a period longer than 6 months has not been described in the literature, particularly in heart patients. The extended varenicline therapy was clinically monitored and allowed the patient to consolidate his abstinence; the intensive behavioural counselling helped him to overcome his strong psychological dependence. Promoting smoking cessation in people who have cardiovascular disease is crucial. Currently available medications, such as varenicline, increase the chances of success and the risk of possible side effects is outweighed by the lifetime benefits and we hope that clinicians use them more frequently and confidently.

Methodological issues in observational studies and non-randomized controlled trials in oncology in the era of big data

Non-randomized controlled trials, cohort studies and database studies are appealing study designs when there are urgent needs for safety data, outcomes of interest are rare, generalizability is a matter of concern, or randomization is not feasible. This paper reviews four typical case studies from methodological viewpoints and clarifies how to minimize bias in observational studies in oncology. In summary, researchers planning observational studies should be cautious of selection of appropriate databases, validity of algorithms for identifying outcomes, comparison with incident users or self-control, rigorous collection of information on potential confounders and reporting details of subject selection. Further, a careful study protocol and statistical analysis plan are also necessary.

Clinical Psychopharmacology Update: Additional Safety Concerns for Using Varenicline (Chantix) for Smoking Cessation Treatment

Smoking cessation remains a positive therapeutic goal and should be encouraged for the millions of individuals who continue to smoke and struggle to quit. While psychiatric nurses should encourage patients to start or continue smoking cessation therapies, they must be aware of the additional safety concerns relating to the use of varenicline (Chantix). Research published subsequent to the last clinical update in this journal (Tobin, 2007 ) has prompted additional warnings from the Food and Drug Administration concerning varenicline for smoking cessation therapy. In particular, clinicians need to be aware of increased concerns about varenicline's association with neuropsychiatric side effects, seizures, and alcohol interactions.

The cytisine derivatives, CC4 and CC26, reduce nicotine-induced conditioned place preference in zebrafish by acting on heteromeric neuronal nicotinic acetylcholine receptors

RATIONALE

Cigarette smoking is one of the most serious health problems worldwide and people trying to stop smoking have high rates of relapse. Zebrafish (Danio rerio), by combining pharmacological and behavioral assays, is a promising animal model for rapidly screening new compounds to induce smoking cessation.

OBJECTIVES

This study aims to identify possible acetylcholine nicotinic receptors (nAChRs) involved in mediating nicotine (NIC)-induced conditioned place preference (CPP) in zebrafish and investigate the effect of the CC4 and CC26 cytisine derivatives in reducing NIC-induced CPP.

METHODS

CPP was evaluated using a two-compartment chamber, and the zebrafish were given CC4 (0.001-5 mg/kg), CC26 (0.001-1 mg/kg), cytisine (0.1-2.5 mg/kg), and varenicline (1-10 mg/kg) alone or with NIC (0.001 mg/kg). Swimming activity was evaluated using a square observational chamber. The affinity of the nicotinic ligands for native zebrafish brain nAChRs was evaluated by binding studies using [(3)H]-Epibatidine (Epi) and [(125)I]-αBungarotoxin (αBgtx) radioligands, and their subtype specificity was determined by means of electrophysiological assay of oocyte-expressed α4β2 and α7 subtypes.

RESULTS

CC4 and CC26 induced CPP with an inverted U-shaped dose-response curve similar to that of NIC. However, when co-administered with NIC, they blocked its reinforcing or slightly aversive effect. Binding and electrophysiological studies showed that this effect was due to binding to high-affinity heteromeric but not α7-containing receptors.

CONCLUSIONS

We have further characterized CC4 and identified a new compound (CC26) that may be active in inducing smoking cessation. Zebrafish is a very useful model for screening new compounds that can affect the rewarding properties of NIC.

Cardiovascular adverse events associated with smoking-cessation pharmacotherapies

Smoking continues to be the leading cause of preventable deaths in the USA, accounting for one in every five deaths every year, and cardiovascular (CV) disease remains the leading cause of those deaths. Hence, there is increasing awareness to quit smoking among the public and counseling plays an important role in smoking cessation. There are different pharmacological methods to help quit smoking that includes nicotine replacement products available over the counter, including patch, gum, and lozenges, to prescription medications, such as bupropion and varenicline. There have been reports of both nonserious and serious adverse CV events associated with the use of these different pharmacological methods, especially varenicline, which has been gaining media attention recently. Therefore, we systematically reviewed the various pharmacotherapies used in smoking cessation and analyzed the evidence behind these CV events reported with these therapeutic agents.

"Tobacco dependence treatment makes no sense because"…: rebuttal of commonly-heard arguments against providing tobacco dependence treatment in the hospital setting

BACKGROUND

The provision of tobacco dependence treatment in health care settings, particularly in countries lacking a history of strong tobacco control policy implementation, is limited by continued misconceptions on the part of health professionals and decision-makers regarding its worth and efficacy. In this paper, we rebut 9 arguments against the provision of tobacco dependence treatment that we have encountered in our experiences implementing and maintaining a dedicated smoking cessation service at a large university hospital in southern Germany.

DISCUSSION

Broadly, the arguments relate to the nature of addiction, the efficacy and safety of stop-smoking medication and behavioural support, and the benefits and challenges of quitting. They include: (a) If smokers really want to quit, they will be able to do it alone (without help); (b) You can't forbid patients from doing what they want; (c) Patients will be upset if you talk to them about their smoking; (d) Stop-smoking medication has side effects that are more dangerous than smoking; (e) You have to be well trained to help smokers to quit (otherwise you can do more harm than good); (f) If you smoke yourself, you lack credibility; (g) If you have cancer, it is too late to quit; (h) Nicotine withdrawal is dangerous for heavy smokers; and (i) Smokers die earlier, thus reducing costs to the health system.

SUMMARY

It is hoped that the counter-arguments presented here arm tobacco control advocates and practitioners working in health care settings, particularly in countries which have not prioritised tobacco control, to respond appropriately and convincingly to those opposed to the provision of tobacco dependence treatment.

Cardiovascular and neuropsychiatric safety of varenicline and bupropion compared with nicotine replacement therapy for smoking cessation: study protocol of a retrospective cohort study using the QResearch general practice database

INTRODUCTION

Cigarette smoking continues to be the leading cause of preventable death and is the main risk factor of major diseases such as chronic obstructive pulmonary disease (COPD). The best treatment to help smokers quit is a combination of behavioural support with pharmacotherapy. Varenicline is the newest drug on the market and has been shown to be effective in the general smoking population and in smokers with COPD. The safety profile of varenicline was initially established using standard approaches to pharmacovigilance, but postmarketing reports have raised concerns about a possible association between the use of varenicline and cardiovascular and neuropsychiatric events. Although recent studies have not confirmed such an association, further research is needed given the large number of smokers who are being prescribed varenicline, including important subgroups such as smokers with COPD who may be particularly vulnerable to side effects of drugs. The aim of this study is to assess the cardiovascular and neuropsychiatric safety of varenicline using data from the QResearch general practice (GP) database.

METHODS AND ANALYSIS

We will conduct a retrospective cohort study in the QResearch GP database. Patients will be categorised into three exposure groups: prescription of (1) varenicline, (2) bupropion or (3) nicotine replacement therapy (NRT Rx; =reference group). We will separately consider major incident neuropsychiatric and cardiovascular outcomes that occur during 6 months of follow-up using Cox proportional hazards models, adjusted for confounders. Furthermore, propensity score analysis will be used as an analytical approach to account for potential confounding by indication.

ETHICS AND DISSEMINATION

This work involves analysis of anonymised, routinely collected data. The protocol has been independently peer-reviewed by the QResearch Scientific Board and meets the requirements of the Trent research ethics committee. We plan to disseminate the results from this study via articles in international peer-reviewed journals and presentations at relevant national and international health conferences.

How good is "evidence" from clinical studies of drug effects and why might such evidence fail in the prediction of the clinical utility of drugs?

Promising evidence from clinical studies of drug effects does not always translate to improvements in patient outcomes. In this review, we discuss why early evidence is often ill suited to the task of predicting the clinical utility of drugs. The current gap between initially described drug effects and their subsequent clinical utility results from deficits in the design, conduct, analysis, reporting, and synthesis of clinical studies-often creating conditions that generate favorable, but ultimately incorrect, conclusions regarding drug effects. There are potential solutions that could improve the relevance of clinical evidence in predicting the real-world effectiveness of drugs. What is needed is a new emphasis on clinical utility, with nonconflicted entities playing a greater role in the generation, synthesis, and interpretation of clinical evidence. Clinical studies should adopt strong design features, reflect clinical practice, and evaluate outcomes and comparisons that are meaningful to patients. Transformative changes to the research agenda may generate more meaningful and accurate evidence on drug effects to guide clinical decision making.

Varenicline and cardiovascular adverse events: a perspective review

Smoking is a leading preventable cause of mortality and morbidity. Varenicline, a first-line smoking cessation aid, is used widely to achieve successful quit rates in smokers. A number of studies and systematic reviews have evaluated the safety profile of the drug. To date, three systematic reviews by Singh and colleagues, Prochaska and Hilton, and Ware and colleagues, published between 2011 and 2013, have evaluated serious cardiovascular adverse events with varenicline use. Even though all three reviews demonstrated that serious cardiovascular adverse events were nominally more frequent in varenicline-treated patients when compared with placebo, a significantly increased event rate was found only in the review by Singh and colleagues. The three reviews included similar trials but differed in the evaluation of outcomes and performance of summary statistic computation. Though the evidence from the two most recent systematic reviews demonstrated that risk of serious cardiovascular events might not be increased with varenicline use, the US Food and Drug Administration has advised prescription with caution combined with close monitoring and education of patients until more conclusive evidence is available. Results of these reviews cannot be generalized to patients with unstable cardiac conditions.

Safety of varenicline tartrate and counseling versus counseling alone for smoking cessation: a randomized controlled trial for inpatients (STOP study)

INTRODUCTION

Inpatient medical settings offer an opportunistic environment for initiating smoking cessation interventions to patients reflecting on their health. Current evidence has shown the superior efficacy of varenicline tartrate (VT) for smoking cessation compared with other tobacco cessation therapies; however, recent evidence also has highlighted concerns about the safety and tolerability of VT. Given these apprehensions, we aimed to evaluate the safety and effectiveness of VT plus quitline-counseling compared to quitline-counseling alone in the inpatient medical setting.

METHODS

Adult patients (n = 392, 20-75 years) admitted with a smoking-related illnesses to 3 hospitals were randomized to receive either 12 weeks of varenicline tartrate (titrated from 0.5mg daily to 1mg twice daily) plus quitline-counseling (VT+C), (n = 196) or quitline-counseling alone (n = 196).

RESULTS

VT was well tolerated in the inpatient setting among subjects admitted with acute smoking-related illnesses (mean age 52.8±2.89 and 53.7±2.77 years in the VT+C and counseling alone groups, respectively). The most common self-reported adverse event during the 12-week treatment phase was nausea (16.3% in the VT+C group compared with 1.5% in the counseling alone group). Thirteen deaths occurred during the study period (n = 6 were in the VT+C arm compared with n = 7 in the counseling alone arm). All of these subjects had known comorbidities or developed underlying comorbidities.

CONCLUSIONS

VT appears to be a safe and well-tolerated opportunistic treatment for inpatient smokers who have related chronic disease. Based on the proven efficacy of varenicline from outpatient studies and our recent inpatient evidence, we suggest it be considered as part of standard care in the hospital setting.

Smoking cessation

Cigarette smoking is a major preventable cause of morbidity and mortality. It is the major risk factor for chronic obstructive pulmonary disease in the developed world. Smoking is a chronic relapsing disease. Optimal treatment includes nonpharmacologic support, together with pharmacotherapy. All clinicians should be comfortable with the use of nicotine replacement therapy, bupropion, and varenicline. Second-line therapies can be used by those familiar with their use. Effective use of these medications requires their integration into an effective management plan, which is likely to be a long-term undertaking, involving several cycles of remission and relapse.

Drugs currently in Phase II clinical trials for cocaine addiction

INTRODUCTION

There are no FDA-approved pharmacotherapies for treating cocaine addiction; thus, developing drugs to treat cocaine dependence is an unmet critical need. Fortunately, there are a number of drugs that are currently in Phase II clinical trial/s. This is due in part to the advances from in vivo imaging in humans which provided a roadmap of the neurochemistry of the cocaine-dependent brain. Most drugs currently in Phase II clinical trials attempt to modulate the disturbed neurochemistry in cocaine dependents to resemble those of healthy individuals. These predominantly modulate dopamine, serotonin, glutamate, GABA or noradrenaline signalling.

AREAS COVERED

This review summarizes the therapeutic potential of each drug as evidenced by clinical and preclinical studies. It also discusses their utility in terms of bioavailability and half-life.

EXPERT OPINION

Amphetamine salts and topiramate clearly stand out in terms of their potential efficacy in treating cocaine addiction. The efficacy of topiramate was closely associated with regular cognitive-behavioural therapy (CBT), which highlights the importance of a combined effort to promote abstinence and enhance retention via CBT. Cognitive/psychological screening appears necessary for a more symptom-based approach with more reasonable outcomes other than abstinence (e.g., improved quality of life) in treating cocaine addiction.

Identification of a new selective dopamine D4 receptor ligand

The dopamine D4 receptor has been shown to play key roles in certain CNS pathologies including addiction to cigarette smoking. Thus, selective D4 ligands may be useful in treating some of these conditions. Previous studies in our laboratory have indicated that the piperazine analog of haloperidol exhibits selective and increased affinity to the DAD4 receptor subtype, in comparison to its piperidine analog. This led to further exploration of the piperazine moiety to identify new agents that are selective at the D4 receptor. Compound 27 (KiD4=0.84 nM) was the most potent of the compounds tested. However, it only had moderate selectivity for the D4 receptor. Compound 28 (KiD4=3.9 nM) while not as potent, was more discriminatory for the D4 receptor subtype. In fact, compound 28 has little or no binding affinity to any of the other four DA receptor subtypes. In addition, of the 23 CNS receptors evaluated, only two, 5HT1AR and 5HT2BR, have binding affinity constants better than 100 nM (Ki <100 nM). Compound 28 is a potentially useful D4-selective ligand for probing disease treatments involving the D4 receptor, such as assisting smoking cessation, reversing cognitive deficits in schizophrenia and treating erectile dysfunction. Thus, further optimization, functional characterization and evaluation in animal models may be warranted.

Pharmacotherapy for smoking cessation: pharmacological principles and clinical practice

Strategies for assisting smoking cessation include behavioural counselling to enhance motivation and to support attempts to quit and pharmacological intervention to reduce nicotine reinforcement and withdrawal from nicotine. Three drugs are currently used as first line pharmacotherapy for smoking cessation, nicotine replacement therapy, bupropion and varenicline. Compared with placebo, the drug effect varies from 2.27 (95% CI 2.02, 2.55) for varenicline, 1.69 (95% CI 1.53, 1.85) for bupropion and 1.60 (95% CI 1.53, 1.68) for any form of nicotine replacement therapy. Despite some controversy regarding the safety of bupropion and varenicline, regulatory agencies consider these drugs as having a favourable benefit/risk profile. However, given the high rate of psychiatric comorbidity in dependent smokers, practitioners should closely monitor patients for neuropsychiatric symptoms. Second-line pharmacotherapies include nortriptyline and clonidine. This review also offers an overview of pipeline developments and issues related to smoking cessation in special populations such as persons with psychiatric comorbidity and pregnant and adolescent smokers.

EPA Guidance on Tobacco Dependence and Strategies for Smoking Cessation in People with Mental Illness

Tobacco dependence is the most common substance use disorder in adults with mental illness. The prevalence rates for tobacco dependence are two to four times higher in these patients than in the general population. Smoking has a strong, negative influence on the life expectancy and quality of life of mental health patients, and remains the leading preventable cause of death in this group. Despite these statistics, in some countries smokers with mental illness are disadvantaged in receiving intervention and support for their tobacco dependence, which is often overlooked or even tolerated. This statement from the European Psychiatric Association (EPA) systematically reviews the current evidence on tobacco dependence and withdrawal in patients with mental illness and their treatment. It provides seven recommendations for the core components of diagnostics and treatment in this patient group. These recommendations concern: (1) the recording process, (2) the timing of the intervention, (3) counselling specificities, (4) proposed treatments, (5) frequency of contact after stopping, (6) follow-up visits and (7) relapse prevention. They aim to help clinicians improve the care, health and well-being of patients suffering from mental illness.

Functional interactions of varenicline and nicotine with nAChR subtypes implicated in cardiovascular control

INTRODUCTION

It has been suggested that varenicline-induced activation of nicotinic acetylcholine receptors (nAChRs) could play a role in the cardiovascular (CV) safety of varenicline. However, since preclinical studies showed that therapeutic varenicline concentrations have no effect in models of CV function, this study examined in vitro profiles of varenicline and nicotine at nAChR subtypes possibly involved in CV control.

METHODS

Concentration-dependent functional effects of varenicline and nicotine at human α3β4, α3α5β4, α7, and α4β2 nAChRs expressed in oocytes were determined by electrophysiology. The proportion of nAChRs predicted to be activated and inhibited by concentrations of varenicline (1mg b.i.d.) and of nicotine in smokers was derived from activation-inhibition curves for each nAChR subtype.

RESULTS

Human varenicline and nicotine concentrations can desensitize and inhibit nAChRs but cause only low-level activation of α3β4, α4β2 (<2%), α7 (<0.05%), and α3α5β4 (<0.01%) nAChRs, which is consistent with literature data. Nicotine concentrations in smokers are predicted to inhibit larger fractions of α3β4 (48%) and α3α5β4 (10%) nAChRs than therapeutic varenicline concentrations (11% and 0.6%, respectively) and to inhibit comparable fractions of α4β2 nAChRs (42%-56%) and α7 nAChRs (16%) as varenicline.

CONCLUSIONS

Nicotine and varenicline concentrations in patients and smokers are predicted to cause minimal activation of ganglionic α3β4* nAChRs, while their functional profiles at α3β4, α3α5β4, α7, and α4β2 nAChRs cannot explain that substituting nicotine from tobacco with varenicline would cause CV adverse events in smokers who try to quit. Other pharmacological properties that could mediate varenicline-induced CV effects have not been identified.

Cardiovascular events associated with smoking cessation pharmacotherapies: a network meta-analysis

BACKGROUND

Stopping smoking is associated with many important improvements in health and quality of life. The use of cessation medications is recommended to increase the likelihood of quitting. However, there is historical and renewed concern that smoking cessation therapies may increase the risk of cardiovascular disease events associated within the quitting period. We aimed to examine whether the 3 licensed smoking cessation therapies-nicotine replacement therapy, bupropion, and varenicline-were associated with an increased risk of cardiovascular disease events using a network meta-analysis.

METHODS AND RESULTS

We searched 10 electronic databases, were in communication with authors of published randomized, clinical trials (RCTs), and accessed internal US Food and Drug Administration reports. We included any RCT of the 3 treatments that reported cardiovascular disease outcomes. Among 63 eligible RCTs involving 21 nicotine replacement therapy RCTs, 28 bupropion RCTs, and 18 varenicline RCTs, we found no increase in the risk of all cardiovascular disease events with bupropion (relative risk [RR], 0.98; 95% confidence interval [CI], 0.54-1.73) or varenicline (RR, 1.30; 95% CI, 0.79-2.23). There was an elevated risk associated with nicotine replacement therapy that was driven predominantly by less serious events (RR, 2.29; 95% CI, 1.39-3.82). When we examined major adverse cardiovascular events, we found a protective effect with bupropion (RR, 0.45; 95% CI, 0.21-0.85) and no clear evidence of harm with varenicline (RR, 1.34; 95% CI, 0.66-2.66) or nicotine replacement therapy (RR, 1.95; 95% CI, 0.26-4.30).

CONCLUSION

Smoking cessation therapies do not appear to raise the risk of serious cardiovascular disease events.

Role of nicotine receptor partial agonists in tobacco cessation

One in three adults in India uses tobacco, a highly addictive substance in one or other form. In addition to prevention of tobacco use, offering evidence-based cessation services to dependent tobacco users constitutes an important approach in addressing this serious public health problem. A combination of behavioral methods and pharmacotherapy has shown the most optimal results in tobacco dependence treatment. Among currently available pharmacological agents, drugs that preferentially act on the α4 β2-nicotinic acetyl choline receptor like varenicline and cytisine appear to have relatively better cessation outcomes. These drugs are in general well tolerated and have minimal drug interactions. The odds of quitting tobacco use are at the very least doubled with the use of partial agonists compared with placebo and the outcomes are also superior when compared to nicotine replacement therapy and bupropion. The poor availability of partial agonists and specifically the cost of varenicline, as well as the lack of safety data for cytisine has limited their use world over, particularly in developing countries. Evidence for the benefit of partial agonists is more robust for smoking rather than smokeless forms of tobacco. Although more studies are needed to demonstrate their effectiveness in different populations of tobacco users, present literature supports the use of partial agonists in addition to behavioral methods for optimal outcome in tobacco dependence.

A double-blind placebo-controlled randomized trial of varenicline for smokeless tobacco dependence in India

INTRODUCTION

The rate of smokeless tobacco use in India is 20%; its use causes serious health problems, and no trial has assessed behavioral or pharmacological treatments for this public health concern. This trial evaluated varenicline for treating smokeless tobacco dependence in India.

METHODS

This was a double-blind placebo-controlled randomized trial of varenicline (12 weeks, 1mg, twice per day) with 237 smokeless tobacco users in India. All participants received behavioral counseling. Outcomes included self-reported and biochemically verified abstinence at the end of treatment (EOT), lapse and recovery events, safety, and medication adherence.

RESULTS

Self-reported EOT abstinence was significantly greater for varenicline (43%) versus placebo (31%; adjusted odds ratio [AOR] = 2.6, 95% CI = 1.2-4.2, p = .009). Biochemically confirmed EOT abstinence was greater for varenicline versus placebo (25.2% vs. 19.5%), but this was not statistically different (AOR = 1.6, 95% CI = 0.84-3.1, p = .15). Compared with placebo, varenicline did not reduce the risk for a lapse (hazard ratio [HR] = 0.86, 95% CI = 0.69-1.1, p = .14), but it did increase the likelihood of recovery to abstinence (HR = 1.2, 95% CI = 1.02-1.4, p = .02). Greater adherence increased EOT cessation rates for varenicline (39% vs. 18%, p = .003) but not for placebo (28% vs. 14%, p = .06). There were no significant differences between varenicline and placebo in rate of side effects, serious adverse events, hypertension, or stopping or reducing medication.

CONCLUSIONS

Varenicline is safe for treating smokeless tobacco dependence in India, and further examination of this medication for this important public health problem is warranted.