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

Canadian Schizophrenia Guidelines: Schizophrenia and Other Psychotic Disorders with Coexisting Substance Use Disorders

OBJECTIVE

Persons with schizophrenia and other psychotic disorders frequently have coexisting substance use disorders that require modifications to treatment approaches for best outcomes. The objectives of this review were to identify evidence-based practices best practices that improve outcomes for individuals with schizophrenia and substance used disorders.

METHOD

We reviewed guidelines that were published in the last 5 years and that included systematic reviews or meta-analyses. Most of our recommendations came from 2 publications from the National Institute for Health and Care Excellence (NICE): the 2011 guidance titled Coexisting Severe Mental Illness (Psychosis) and Substance Misuse: Assessment and Management in Healthcare Settings and the 2014 guidance titled Psychosis and Schizophrenia in Adults: Prevention and Management. We placed these recommendations into the Canadian context to create this guideline.

RESULTS

Evidence supports the inclusion of individuals with coexisting substance use disorders in first-episode psychosis programs. The programs should integrate psychosis and substance use treatments, emphasizing ongoing monitoring of both substance use and patterns and symptoms. The best outcomes are achieved with combined use of antipsychotic medications and addiction-based psychosocial interventions. However, limited evidence is available to recommend using one antipsychotic medication over another or one psychosocial intervention over another for persons with schizophrenia and other psychotic disorders with coexisting substance use disorders.

CONCLUSIONS

Treating persons who have schizophrenia and other psychotic disorders with coexisting substance use disorders can present clinical challenges, but modifications in practice can help engage and retain people in treatment, where significant improvements over time can be expected.

Nicotine and networks: Potential for enhancement of mood and cognition in late-life depression

Late-life depression is characterized by both lower mood and poor cognitive performance, symptoms that often do not fully respond to current antidepressant medications. Nicotinic acetylcholine receptor (nAChR) agonists such as nicotine may serve as a novel therapeutic approach for this population. Both preclinical and preliminary clinical studies suggest that nAChR agonists can improve depressive behavior in animal models and improve mood in depressed individuals. Substantial literature also supports that nAChR agonists benefit cognitive performance, particularly in older populations. These potential benefits may be mediated by the effects of nAChR stimulation on neural network function and connectivity. Functional neuroimaging studies detail effects of nAChR agonists on the default mode network, central-executive network, and salience network that may oppose or reverse network changes seen in depression. We propose that, given the existent literature and the clinical presentation of late-life depression, nicotine or other nAChR agonists may have unique therapeutic benefits in this population and that clinical trials examining nicotine effects on mood, cognition, and network dynamics in late-life depression are justified.

Using the affective bias test to predict drug-induced negative affect: implications for drug safety

Background and Purpose

Predicting the risk of drug‐induced adverse psychiatric effects is important but currently not possible in non‐human species. We investigated whether the affective bias test (ABT) could provide a preclinical method with translational and predictive validity.

Experimental Approach

The ABT is a bowl‐digging task, which quantifies biases associated with learning and memory. Rats encounter independent learning experiences, on separate days, under either acute manipulations (e.g. pro‐depressant vs. control) or different absolute reward values (e.g. high vs. low). A bias is observed during a preference test when an animal's choices reflect their prior experience. We investigated the effects of putative pro‐depressant drug treatments following acute or chronic administration on the formation of an affective bias or reward‐induced positive bias respectively.

Key Results

The immunomodulators LPS (10 μg·kg⁻¹), corticosterone (10 and 30 mg·kg⁻¹) and IFN‐α (100 U·kg⁻¹) induced a negative affective bias following acute treatment. Tetrabenazine (1 mg·kg⁻¹) also induced a negative bias, but no effects were observed with varenicline, carbamazepine or montelukast. Chronic treatment with IFN‐α (100 U·kg⁻¹) and retinoic acid (10 mg·kg⁻¹) impaired the formation of a reward‐induced positive bias but did not alter sucrose preference test (SPT).

Conclusions and Implications

The ABT has the potential to provide a novel approach to predict pro‐depressant risk in a non‐human species. Negative biases induced by acute treatment in the standard version of the task may also predict longer‐term effects on reward processing as shown by the deficit in reward‐induced positive bias following chronic treatment, an effect distinct from anhedonia in the SPT.

Linked Articles

This article is part of a themed section on Pharmacology of Cognition: a Panacea for Neuropsychiatric Disease? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.19/issuetoc

How do smoking cessation medicines compare with respect to their neuropsychiatric safety? A protocol for a systematic review, network meta-analysis and cost-effectiveness analysis

INTRODUCTION

Cigarette smoking is one of the leading causes of early death in the UK and worldwide. Public health guidance recommends the use of varenicline, bupropion and nicotine replacement therapy (NRT) as smoking cessation aids in the UK. Additionally, the first electronic cigarette has been licensed for use as a smoking cessation medicine. However, there are ongoing concerns about the safety of these medicines. We present a protocol for a systematic review and network meta-analysis (NMA) to determine how these smoking cessation medicines compare to each other with respect to their neuropsychiatric safety in adult smokers. Secondary aims include updating the evidence regarding the effectiveness and cardiovascular safety of these medicines for use in a cost-effectiveness analysis.

METHODS AND ANALYSIS

We will include randomised controlled trials and observational studies with control groups comparing monotherapy with varenicline, bupropion, NRT or electronic cigarette and combination therapies to each other, placebo or usual care. The primary composite safety outcome will be serious adverse events, defined as events that resulted in death, were life threatening, required hospitalisation or resulted in significant disability or congenital/birth defect. The preferred effectiveness outcome will be sustained smoking cessation defined as abstinence for a minimum of 6 months as determined by biochemical validation. We will include trials identified by previous reviews and search relevant databases for newly published trials as well as contacting study authors to identify unpublished information. We will conduct fixed-effect and random-effect meta-analyses for each pairwise comparison of treatments and outcome; where these estimates differ, we will consider reasons for heterogeneity, quantified using the between-study variance (τ²). For each outcome, we will construct a NMA in a Bayesian framework which will be compared with the pair-wise results, allowing us to rank treatments. The effectiveness estimates from the NMA will be entered into a probabilistic economic model.

ETHICS AND DISSEMINATION

Ethics approval is not required for this evidence synthesis study as it involves analysis of secondary data from randomised controlled trials and observational studies. The review will make an important contribution to the knowledge base around the effectiveness, safety and cost-effectiveness of smoking cessation medicines. Results will be disseminated to the general public, healthcare practitioners and clinicians, academics, industry and policy makers.

PROSPERO REGISTRATION NUMBER

CRD42016041302.

Treating tobacco dependence: guidance for primary care on life-saving interventions. Position statement of the IPCRG

Tobacco smoking is the world's leading cause of premature death and disability. Global targets to reduce premature deaths by 25% by 2025 will require a substantial increase in the number of smokers making a quit attempt, and a significant improvement in the success rates of those attempts in low, middle and high income countries. In many countries the only place where the majority of smokers can access support to quit is primary care. There is strong evidence of cost-effective interventions in primary care yet many opportunities to put these into practice are missed. This paper revises the approach proposed by the International Primary Care Respiratory Group published in 2008 in this journal to reflect important new evidence and the global variation in primary-care experience and knowledge of smoking cessation. Specific for primary care, that advocates for a holistic, bio-psycho-social approach to most problems, the starting point is to approach tobacco dependence as an eminently treatable condition. We offer a hierarchy of interventions depending on time and available resources. We present an equitable approach to behavioural and drug interventions. This includes an update to the evidence on behaviour change, gender difference, comparative information on numbers needed to treat, drug safety and availability of drugs, including the relatively cheap drug cytisine, and a summary of new approaches such as harm reduction. This paper also extends the guidance on special populations such as people with long-term conditions including tuberculosis, human immunodeficiency virus, cardiovascular disease and respiratory disease, pregnant women, children and adolescents, and people with serious mental illness. We use expert clinical opinion where the research evidence is insufficient or inconclusive. The paper describes trends in the use of waterpipes and cannabis smoking and offers guidance to primary-care clinicians on what to do faced with uncertain evidence. Throughout, it recognises that clinical decisions should be tailored to the individual's circumstances and attitudes and be influenced by the availability and affordability of drugs and specialist services. Finally it argues that the role of the International Primary Care Respiratory Group is to improve the confidence as well as the competence of primary care and, therefore, makes recommendations about clinical education and evaluation. We also advocate for an update to the WHO Model List of Essential Medicines to optimise each primary-care intervention. This International Primary Care Respiratory Group statement has been endorsed by the Member Organisations of World Organization of Family Doctors Europe.

Construction of an enantiopure bivalent nicotine vaccine using synthetic peptides

Clinical outcomes of anti-nicotine vaccines may be improved through enhancements in serum antibody affinity and concentration. Two strategies were explored to improve vaccine efficacy in outbred mice: the use of enantiopure haptens and formulation of a bivalent vaccine. Vaccines incorporating natural (-) nicotine haptens improved relative antibody affinities >10-fold over (+) haptens, stimulated a two-fold boost in nicotine serum binding capacity, and following injection with 3 cigarette equivalents of nicotine, prevented a larger proportion of nicotine (>85%) from reaching the brain. The activity of a bivalent vaccine containing (-) 3’AmNic and (-) 1’SNic haptens was then compared to dose-matched monovalent groups. It was confirmed that antisera generated by these structurally distinct haptens have minimal cross-reactivity and stimulate different B cell populations. Equivalent antibody affinities were detected between the three groups, but the bivalent group showed two-fold higher titers and an additive increase in nicotine serum binding capacity as compared to the monovalent groups. Mice immunized with the bivalent formulation also performed better in a nicotine challenge experiment, and prevented >85% of a nicotine dose equivalent to 12 cigarettes from reaching the brain. Overall, enantiopure conjugate vaccines appear to improve serum antibody affinity, while multivalent formulations increase total antibody concentration. These findings may help improve the performance of future clinical candidate vaccines.

Identification and Characteristics of Time-Related Shifts in Suicide-Related Event Frequency During Smoking Cessation Treatment with Varenicline

Objectives: To survey time-related shifts in number of suicide-related events (SRE) during smoking cessation treatment with varenicline (VAR) in cases from the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS), as well as the characteristics of these shifts. Methods: We isolated cases from the FAERS database involving VAR usage where SRE was reported as an adverse event (SRE+/VAR+ case) and established a histogram of SRE+/VAR+ case numbers per week. Furthermore, we focused on "cases reporting specific adverse events prior to drug usage start" using X-bar and R chart concepts. We also attempted to exclude the influence of smoking history from the created histogram. Moreover, we constructed a histogram on central nervous system adverse events, which were frequently seen during VAR usage. Results: By removing the effects of smoking history, SRE onset signals were detected over a long period from the start of VAR use. However, expression signals for nausea and abnormal dreams were detected only in the early VAR administration period. Discussion: These results suggest that VAR use-induced SRE is expressed over a long timeframe from the start of treatment. Additionally, the period of SRE expression signal detection was longer than that of the other central nervous system adverse events (nausea and abnormal dreams). Therefore, SRE onset must be carefully monitored during smoking cessation treatment with VAR over the entire treatment period.

Efficacy and Safety of Smoking Cessation Interventions in Patients With Cardiovascular Disease

Background—

Although the efficacy and safety of smoking cessation interventions are well established, their efficacy and safety in patients with cardiovascular disease (CVD) remain unclear. The objective of this study was to evaluate the efficacy and safety of pharmacological and behavioral smoking cessation interventions in CVD patients via a meta-analysis of randomized controlled trials.

Methods and Results—

EMBASE, PsycINFO, MEDLINE, PubMed, and the Cochrane Tobacco Addiction Specialized Register were searched for randomized controlled trials evaluating the efficacy of smoking cessation pharmacotherapies and behavioral therapies in CVD patients. Outcomes of interest were smoking abstinence at 6 and 12 months, defined using the most rigorous criteria reported. Data were pooled across studies for direct comparisons using random-effects models. Network meta-analysis using a graph-theoretical approach was used to generate the indirect comparisons. Seven pharmacotherapy randomized controlled trials (n=2809) and 17 behavioral intervention randomized controlled trials (n=4666) met our inclusion criteria. Our network meta-analysis revealed that varenicline (relative risk [RR]: 2.64; 95% confidence interval [CI], 1.34–5.21) and bupropion (RR: 1.42; 95% CI, 1.01–2.01) were associated with greater abstinence than placebo. The evidence about nicotine replacement therapies was inconclusive (RR: 1.22; 95% CI, 0.72–2.06). Telephone therapy (RR: 1.47; 95% CI: 1.15–1.88) and individual counseling (RR: 1.64, 95% CI: 1.17–2.28) were both more efficacious than usual care, whereas in-hospital behavioral interventions were not (RR: 1.05; 95% CI, 0.78–1.43).

Conclusions—

Our meta-analysis suggests varenicline and bupropion, as well as individual and telephone counseling, are efficacious for smoking cessation in CVD patients.

Smoking, Mental Illness, and Public Health

Tobacco use remains the leading preventable cause of death worldwide. In particular, people with mental illness are disproportionately affected with high smoking prevalence; they account for more than 200,000 of the 520,000 tobacco-attributable deaths in the United States annually and die on average 25 years prematurely. Our review aims to provide an update on smoking in the mentally ill. We review the determinants of tobacco use among smokers with mental illness, presented with regard to the public health HAVE framework of “the host” (e.g., tobacco user characteristics), the “agent” (e.g., nicotine product characteristics), the “vector” (e.g., tobacco industry), and the “environment” (e.g., smoking policies). Furthermore, we identify the significant health harms incurred and opportunities for prevention and intervention within a health care systems and larger health policy perspective. A comprehensive effort is warranted to achieve equity toward the 2025 Healthy People goal of reducing US adult tobacco use to 12%, with attention to all subgroups, including smokers with mental illness.

Assessment of the Risk of Suicide-Related Events Induced by Concomitant Use of Antidepressants in Cases of Smoking Cessation Treatment with Varenicline and Assessment of Latent Risk by the Use of Varenicline

Smoking Cessation Treatment (SCT) is a policy that has to be promoted for health economics, and expectations for the success of treatments with varenicline (VAR) are large. However, the Food and Drug Administration (FDA) have issued a warning on VAR-induced depression and suicide. In the present study, utilizing the FDA Adverse Event Reporting System (FAERS), we searched for antidepressants (ADs) used during SCT that cause fewer suicide-related events (SRE) (Study 1). We also investigated whether VAR concomitantly administered with ADs increases the risk of SRE (Study 2). In addition, we investigated whether the use of VAR alone is a latent risk factor of SRE. The backgrounds of cases with and without SRE were matched using the Propensity Score. In Study 1, the highest integrated Reporting Odds Ratio (iROR) was noted in concomitantly administered mirtazapine (iROR 6.98; 95% Confidence Interval (CI) 1.57-30.99), while the lowest ratio was noted in concomitantly administered amitriptyline (iROR 0.59; iROR95%CI 0.23-1.50). Study 2 clarified that SCT increases the risk of SRE in AD-treated cases (iROR 8.02; iROR95%CI 5.47-11.76; not significance). Of ADs concomitantly used during SCT with VAR, amitriptyline and mirtazapine showed the lowest and highest risks, respectively (Study 1). It was clarified that concomitant use of VAR in the treatment of depression with ADs increased the risk of SRE (Study 2). The results of Studies 1 and 2 suggested that the use of VAR alone is a latent risk factor inducing suicide.

Combining Varenicline (Chantix) with Naltrexone Decreases Alcohol Drinking More Effectively Than Does Either Drug Alone in a Rodent Model of Alcoholism

BACKGROUND

This study examined whether varenicline (VAR), or naltrexone (NTX), alone or in combination, reduces alcohol drinking in alcohol-preferring (P) rats with a genetic predisposition toward high voluntary alcohol intake.

METHODS

Alcohol-experienced P rats that had been drinking alcohol (15% v/v) for 2 h/d for 4 weeks were fed either vehicle (VEH), VAR alone (0.5, 1.0, or 2.0 mg/kg body weight [BW]), NTX alone (10.0, 15.0, or 20.0 mg/kg BW), or VAR + NTX in 1 of 4 dose combinations (0.5 VAR + 10.0 NTX, 0.5 VAR + 15.0 NTX, 1.0 VAR + 10.0 NTX, or 1.0 VAR + 15.0 NTX) at 1 hour prior to alcohol access for 10 consecutive days, and the effects on alcohol intake were assessed.

RESULTS

When administered alone, VAR in doses of 0.5 or 1.0 mg/kg BW did not alter alcohol intake but a dose of 2.0 mg/kg BW decreased alcohol intake. This effect disappeared when drug treatment was terminated. NTX in doses of 10.0 and 15.0 mg/kg BW did not alter alcohol intake but a dose of 20.0 mg/kg BW decreased alcohol intake. Combining low doses of VAR and NTX into a single medication reduced alcohol intake as well as did high doses of each drug alone. Reduced alcohol intake occurred immediately after onset of treatment with the combined medication and continued throughout prolonged treatment.

CONCLUSIONS

Low doses of VAR and NTX, when combined in a single medication, reduce alcohol intake in a rodent model of alcoholism. This approach has the advantage of reducing potential side effects associated with each drug. Lowering the dose of NTX and VAR in a combined treatment approach that maintains efficacy while reducing the incidence of negative side effects may increase patient compliance and improve clinical outcomes for alcoholics and heavy drinkers who want to reduce their alcohol intake.

Varenicline for smoking cessation and reduction in people with severe mental illnesses: systematic review and meta-analysis

AIMS

To determine the effectiveness and safety of varenicline in treating tobacco dependence in patients with severe mental illness.

DESIGN

A systematic review and meta-analysis of randomised controlled trials that compared varenicline with a placebo or an alternative intervention for smoking cessation or reduction.

SETTING

Both in- and out-patient settings in any country.

PARTICIPANTS

Adult patients aged 18 years and over with any type of severe mental illness. The systematic review included eight studies comprising 398 participants.

MEASURES

Primary outcome measures were (1) smoking cessation, (2) smoking reduction measured by changes in the number of cigarettes smoked per day and (3) number of psychiatric adverse events, which were collected at the end of treatment.

FINDINGS

The random-effect pooled estimates from the five studies that reported smoking-related outcomes found that varenicline is statistically superior to placebo in smoking cessation [risk ratios 4.33; 95% confidence interval (CI) = 1.96-9.56], and smoking reduction was higher in varenicline groups (mean reduced daily cigarettes was 6.39; 95% CI = 2.22-10.56). There is no significant difference regarding neuropsychiatric and other adverse events.

CONCLUSIONS

Varenicline appears to be significantly more effective than placebo in assisting with smoking cessation and reduction in people with severe mental illness. There appears to be no clear evidence that varenicline was associated with an increased risk of neuropsychiatric or other adverse events compared with placebo.

Trends in Use of Medications for Smoking Cessation in Medicare, 2007-2012

INTRODUCTION

Smoking-related disease accounts for 10% of Medicare expenditures. Although clinical guidelines recommend smoking-cessation medications, they are subject to safety warnings from the U.S. Food and Drug Administration (FDA). This study investigated trends in utilization of smoking-cessation medications in Medicare from 2007 to 2012.

METHODS

Data on medical claims and prescription drugs for a nationally representative sample of Medicare beneficiaries were used to study trends from 2007 to 2012 in use of smoking-cessation medications (bupropion, nicotine-replacement therapy, varenicline), among beneficiaries who used tobacco (N=205,675). Analyses were conducted in 2015. Multinomial logistic regression was used to examine differences in use of bupropion, nicotine-replacement therapy, varenicline, or more than one medication, relative to none, by beneficiaries' health and demographic characteristics. Binary logistic regression calculated average predicted probabilities of cardiovascular disease or depression among medication users before and after FDA safety warnings related to those conditions.

RESULTS

Sixteen percent of tobacco users ever filled a prescription for a smoking-cessation medication. The proportion of beneficiaries who filled prescriptions for varenicline increased in 2007 but sharply declined corresponding to public warnings about adverse effects, although the same trends did not occur for bupropion or nicotine-replacement therapy. After FDA safety concerns were published, the average predicted probability of beneficiaries filling varenicline prescriptions with cardiovascular disease declined by 31%, although the average predicted probability of depression did not decline.

CONCLUSIONS

Use of smoking-cessation medications among Medicare beneficiaries remains low. Health effects of Medicare policies that increase coverage for medical support for smoking cessation may be limited by low utilization of effective medications.

Update in Outpatient General Internal Medicine: Practice-Changing Evidence Published in 2015

Identifying new practice-changing articles is challenging. To determine the 2015 practice-changing articles most relevant to outpatient general internal medicine, 3 internists independently reviewed the titles and abstracts of original articles, synopses of single studies and syntheses, and databases of syntheses. For original articles, internal medicine journals with the 7 highest impact factors were reviewed: New England Journal of Medicine, Lancet, Journal of the American Medical Association (JAMA), British Medical Journal, Public Library of Science Medicine, Annals of Internal Medicine, and JAMA Internal Medicine. For synopses of single studies and syntheses, collections in American College of Physicians Journal Club, Journal Watch, and Evidence-Based Medicine were reviewed. For databases of synthesis, Evidence Updates and the Cochrane Library were reviewed. More than 100 articles were identified. Criteria for inclusion were as follows: clinical relevance, potential for practice change, and strength of evidence. Clusters of important articles around one topic were considered as a single-candidate series. The 5 authors used a modified Delphi method to reach consensus on inclusion of 7 topics for in-depth appraisal.

A comparison of neuropsychiatric adverse events during early treatment with varenicline or a nicotine patch

AIMS

We compared the risk of mental health episodes requiring hospitalization (primary aim) or out-patient clinic visits (secondary aim) associated with varenicline versus the nicotine patch (NP) in an era prior to psychiatric boxed warnings.

DESIGN

Retrospective cohort.

SETTING

Department of Veterans Affairs (VA), USA.

PARTICIPANTS

VA patients with or without psychiatric comorbidities and a new prescription for varenicline (15 255) were propensity score-matched (1 : 2) to new users of NP (123 054) between 1 May 2006 and 30 September 2007, resulting in 11 774 and 23 548 patients in the varenicline and NP groups, respectively.

MEASUREMENTS

The primary outcomes were hospitalizations with a primary discharge diagnosis of a range of mental health disorders: depression, schizophrenia, bipolar disorder, suicide attempt, post-traumatic stress disorder, other psychosis and drug-induced mental disorders. Secondary outcomes were out-patient clinic visits with a primary diagnosis of the above list of mental health disorders.

FINDINGS

Background characteristics of the treatment groups were similar after matching. There was no statistically significant difference in risk of hospitalization for any of the studied mental health disorders with varenicline compared with NP. Among secondary outcomes there was an increased risk of out-patient clinic visits for schizophrenia among patients who received varenicline [hazard ratio (HR) = 1.27; 95% confidence interval (CI) = 1.07, 1.51], this increase being evident only in those with a pre-existing mental health disorder.

CONCLUSION

In US VA patients studied prior to the boxed warning being implemented, use of varenicline for smoking cessation was not associated with a detectable increase compared with nicotine patches in hospitalization for any mental health outcomes. There was an increased rate of out-patient attendances with a primary diagnosis of schizophrenia amounting to five per 100 person years of treatment. This increase was found only in patients with a pre-existing mental health disorder.

Pharmacotherapy for Substance Use Disorders

This article reviews the current pharmacotherapy options available for the treatment of patients with substance use disorders. In the United States there are medications available to treat tobacco use disorders (nicotine replacement, bupropion, and varenicline), alcohol use disorders (naltrexone and acamprosate), and opioid use disorders (methadone and buprenorphine). These medications are likely underused and physicians should more readily prescribe for eligible patients.

Neuropsychiatric safety and efficacy of varenicline, bupropion, and nicotine patch in smokers with and without psychiatric disorders (EAGLES): a double-blind, randomised, placebo-controlled clinical trial

BACKGROUND

Substantial concerns have been raised about the neuropsychiatric safety of the smoking cessation medications varenicline and bupropion. Their efficacy relative to nicotine patch largely relies on indirect comparisons, and there is limited information on safety and efficacy in smokers with psychiatric disorders. We compared the relative neuropsychiatric safety risk and efficacy of varenicline and bupropion with nicotine patch and placebo in smokers with and without psychiatric disorders.

METHODS

We did a randomised, double-blind, triple-dummy, placebo-controlled and active-controlled (nicotine patch; 21 mg per day with taper) trial of varenicline (1 mg twice a day) and bupropion (150 mg twice a day) for 12 weeks with 12-week non-treatment follow-up done at 140 centres (clinical trial centres, academic centres, and outpatient clinics) in 16 countries between Nov 30, 2011, and Jan 13, 2015. Participants were motivated-to-quit smokers with and without psychiatric disorders who received brief cessation counselling at each visit. Randomisation was computer generated (1:1:1:1 ratio). Participants, investigators, and research personnel were masked to treatment assignments. The primary endpoint was the incidence of a composite measure of moderate and severe neuropsychiatric adverse events. The main efficacy endpoint was biochemically confirmed continuous abstinence for weeks 9-12. All participants randomly assigned were included in the efficacy analysis and those who received treatment were included in the safety analysis. The trial is registered at ClinicalTrials.gov (number NCT01456936) and is now closed.

FINDINGS

8144 participants were randomly assigned, 4116 to the psychiatric cohort (4074 included in the safety analysis) and 4028 to the non-psychiatric cohort (3984 included in the safety analysis). In the non-psychiatric cohort, 13 (1·3%) of 990 participants reported moderate and severe neuropsychiatric adverse events in the varenicline group, 22 (2·2%) of 989 in the bupropion group, 25 (2·5%) of 1006 in the nicotine patch group, and 24 (2·4%) of 999 in the placebo group. The varenicline-placebo and bupropion-placebo risk differences (RDs) for moderate and severe neuropsychiatric adverse events were -1·28 (95% CI -2·40 to -0·15) and -0·08 (-1·37 to 1·21), respectively; the RDs for comparisons with nicotine patch were -1·07 (-2·21 to 0·08) and 0·13 (-1·19 to 1·45), respectively. In the psychiatric cohort, moderate and severe neuropsychiatric adverse events were reported in 67 (6·5%) of 1026 participants in the varenicline group, 68 (6·7%) of 1017 in the bupropion group, 53 (5·2%) of 1016 in the nicotine patch group, and 50 (4·9%) of 1015 in the placebo group. The varenicline-placebo and bupropion-placebo RDs were 1·59 (95% CI -0·42 to 3·59) and 1·78 (-0·24 to 3·81), respectively; the RDs versus nicotine patch were 1·22 (-0·81 to 3·25) and 1·42 (-0·63 to 3·46), respectively. Varenicline-treated participants achieved higher abstinence rates than those on placebo (odds ratio [OR] 3·61, 95% CI 3·07 to 4·24), nicotine patch (1·68, 1·46 to 1·93), and bupropion (1·75, 1·52 to 2·01). Those on bupropion and nicotine patch achieved higher abstinence rates than those on placebo (OR 2·07 [1·75 to 2·45] and 2·15 [1·82 to 2·54], respectively). Across cohorts, the most frequent adverse events by treatment group were nausea (varenicline, 25% [511 of 2016 participants]), insomnia (bupropion, 12% [245 of 2006 participants]), abnormal dreams (nicotine patch, 12% [251 of 2022 participants]), and headache (placebo, 10% [199 of 2014 participants]). Efficacy treatment comparison did not differ by cohort.

INTERPRETATION

The study did not show a significant increase in neuropsychiatric adverse events attributable to varenicline or bupropion relative to nicotine patch or placebo. Varenicline was more effective than placebo, nicotine patch, and bupropion in helping smokers achieve abstinence, whereas bupropion and nicotine patch were more effective than placebo.

FUNDING

Pfizer and GlaxoSmithKline.

Faster drug approval: challenges for safety

INTRODUCTION

More rapid drug premarketing procedures pose a challenge for regulatory agencies in terms of innovation and improving real-world safety and effectiveness Areas covered: This review considers the blockbuster drugs used over the previous fifteen years with adverse reactions after marketing, the elements and time span of risk identification and the measures implemented or considered, based on the existing literature and reports from the agencies Expert opinion: Risk prediction is founded on several factors: randomization, sample size, a well-established endpoint for safety, use of a comparator rather than placebo and a longer Phase-III period, in which a serious illness may be identified by early signs of alteration in the primary parenchyma with the latest biochemical, instrumental and imaging techniques. In comparative non-inferiority evaluations, increased safety should be preferred, with the exception of drugs that may be useful in serious or life-threatening diseases for which there are few or no effective existing therapies. A period of restricted use may be required to test and dispense new drugs, as well as to implement specific methods for the early detection of adverse events. It is important not to regard a new medicine axiomatically as the best treatment before it comes into wide use.

Nicotine receptor partial agonists for smoking cessation

BACKGROUND

Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist).

OBJECTIVES

To review the efficacy of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('cytisine' or 'Tabex' or 'dianicline' or 'varenicline' or 'nicotine receptor partial agonist') in the title or abstract, or as keywords. The register is compiled from searches of MEDLINE, EMBASE, and PsycINFO using MeSH terms and free text to identify controlled trials of interventions for smoking cessation and prevention. We contacted authors of trial reports for additional information where necessary. The latest update of the specialised register was in May 2015, although we have included a few key trials published after this date. We also searched online clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion and nicotine patches where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data on the type of participants, the dose and duration of treatment, the outcome measures, the randomisation procedure, concealment of allocation, and completeness of follow-up.The main outcome measured was abstinence from smoking at longest follow-up. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we pooled risk ratios (RRs), using the Mantel-Haenszel fixed-effect model.

MAIN RESULTS

Two trials of cytisine (937 people) found that more participants taking cytisine stopped smoking compared with placebo at longest follow-up, with a pooled risk ratio (RR) of 3.98 (95% confidence interval (CI) 2.01 to 7.87; low-quality evidence). One recent trial comparing cytisine with NRT in 1310 people found a benefit for cytisine at six months (RR 1.43, 95% CI 1.13 to 1.80).One trial of dianicline (602 people) failed to find evidence that it was effective (RR 1.20, 95% CI 0.82 to 1.75). This drug is no longer in development.We identified 39 trials that tested varenicline, 27 of which contributed to the primary analysis (varenicline versus placebo). Five of these trials also included a bupropion treatment arm. Eight trials compared varenicline with nicotine replacement therapy (NRT). Nine studies tested variations in varenicline dosage, and 13 tested usage in disease-specific subgroups of patients. The included studies covered 25,290 participants, 11,801 of whom used varenicline.The pooled RR for continuous or sustained abstinence at six months or longer for varenicline at standard dosage versus placebo was 2.24 (95% CI 2.06 to 2.43; 27 trials, 12,625 people; high-quality evidence). Varenicline at lower or variable doses was also shown to be effective, with an RR of 2.08 (95% CI 1.56 to 2.78; 4 trials, 1266 people). The pooled RR for varenicline versus bupropion at six months was 1.39 (95% CI 1.25 to 1.54; 5 trials, 5877 people; high-quality evidence). The RR for varenicline versus NRT for abstinence at 24 weeks was 1.25 (95% CI 1.14 to 1.37; 8 trials, 6264 people; moderate-quality evidence). Four trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated during long-term use. The number needed to treat with varenicline for an additional beneficial outcome, based on the weighted mean control rate, is 11 (95% CI 9 to 13). The most commonly reported adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. Our analysis of reported serious adverse events occurring during or after active treatment suggests there may be a 25% increase in the chance of SAEs among people using varenicline (RR 1.25; 95% CI 1.04 to 1.49; 29 trials, 15,370 people; high-quality evidence). These events include comorbidities such as infections, cancers and injuries, and most were considered by the trialists to be unrelated to the treatments. There is also evidence of higher losses to follow-up in the control groups compared with the intervention groups, leading to a likely underascertainment of the true rate of SAEs among the controls. Early concerns about a possible association between varenicline and depressed mood, agitation, and suicidal behaviour or ideation led to the addition of a boxed warning to the labelling in 2008. However, subsequent observational cohort studies and meta-analyses have not confirmed these fears, and the findings of the EAGLES trial do not support a causal link between varenicline and neuropsychiatric disorders, including suicidal ideation and suicidal behaviour. The evidence is not conclusive, however, in people with past or current psychiatric disorders. Concerns have also been raised that varenicline may slightly increase cardiovascular events in people already at increased risk of those illnesses. Current evidence neither supports nor refutes such an association, but we await the findings of the CATS trial, which should establish whether or not this is a valid concern.

AUTHORS' CONCLUSIONS

Cytisine increases the chances of quitting, although absolute quit rates were modest in two recent trials. Varenicline at standard dose increased the chances of successful long-term smoking cessation between two- and three-fold compared with pharmacologically unassisted quit attempts. Lower dose regimens also conferred benefits for cessation, while reducing the incidence of adverse events. More participants quit successfully with varenicline than with bupropion or with NRT. Limited evidence suggests that varenicline may have a role to play in relapse prevention. The most frequently recorded adverse effect of varenicline is nausea, but mostly at mild to moderate levels and tending to subside over time. Early reports of possible links to suicidal ideation and behaviour have not been confirmed by current research.Future trials of cytisine may test extended regimens and more intensive behavioural support.

Efficacy and tolerability of pharmacotherapy for smoking cessation in adults with serious mental illness: a systematic review and network meta-analysis

BACKGROUND AND AIMS

To assess the efficacy and tolerability of adjunctive pharmacotherapy for smoking cessation in adults with serious mental illness (SMI) by means of a systematic review and network meta-analysis.

METHOD

We searched Embase, Medline, PsychINFO and the Cochrane Central Register of Controlled Trials from database inception to 1 December 2014 for randomized controlled trials (RCTs) published in English. We included all studies of smokers with SMI (including schizophrenia, schizoaffective disorder, bipolar disorder, delusional disorder and depressive psychoses) who were motivated to quit smoking. Pharmacotherapies included nicotine replacement therapy (NRT), bupropion and varenicline delivered as monotherapy or in combination compared with each other or placebo. The efficacy outcome was self-reported sustained smoking cessation, verified biochemically at the longest reported time-point. The tolerability outcome was number of patients discontinuing the trial due to any adverse event.

RESULTS

Seventeen study reports were included, which represented 14 individual RCTs. No trials were found in patients with depressive psychoses, delusional disorder or that compared NRT monotherapy with placebo. A total of 356 and 423 participants were included in the efficacy and tolerability analyses, respectively. From the network meta-analysis, both bupropion and varenicline were more effective than placebo [odds ratio (OR) = 4.51, 95% credible interval (CrI) = 1.45-14.04 and OR = 5.17, 95% CrI = 1.78-15.06, respectively]. Data were insensitive to an assessment of varenicline versus bupropion (OR = 1.15, 95% CrI = 0.24-5.45). There were no significant differences in tolerability. All outcomes were rated by GRADE criteria as very low quality.

CONCLUSIONS

The limited evidence available to date suggests that bupropion and varenicline are effective and tolerable for smoking cessation in adults with serious mental illnesses.

Varenicline for smoking cessation: a narrative review of efficacy, adverse effects, use in at-risk populations, and adherence

Treating tobacco dependence is the most effective way to reduce tobacco-related death and disability. Counseling and pharmacotherapy have been shown to increase tobacco abstinence rates among smokers. Varenicline is the most effective monotherapy treatment for tobacco dependence; however, it is prescribed less often than indicated, and adherence is less than optimal. We conducted a literature review of the development, efficacy, safety, contraindications, and adverse effects of varenicline; including reviewing data regarding combination therapy, extended duration, and patient adherence. Varenicline was developed to work specifically on the factors that underlie nicotine addiction. Phase II and Phase III trials established dosing, safety profiles, and efficacy. Postmarketing research raised concerns about neuropsychiatric and cardiac effects, resulting in warning labels being added and modified to encourage discussions with patients weighing the risks and benefits. While more research is needed, evidence is strong that varenicline is safe and effective in treating tobacco dependence among people who are at higher risk for neuropsychiatric symptoms and cardiovascular disease. The effectiveness of varenicline can be improved by taking it in combination with other medications, enhancing patient adherence and extending the duration of treatment.

Varenicline improves motor and cognitive symptoms in early Huntington's disease

The aim of this study was to describe the effects of varenicline, a smoking cessation aid that acts as a nicotinic agonist, on cognitive function in patients with early clinical Huntington's disease (HD) who were current smokers. Three gene-positive patients transitioning to symptomatic HD were evaluated using the Unified Huntington's Disease Rating Scale part I and III (motor and behavioral subscales) at baseline and after 4 weeks of treatment. Cognitive function was assessed using a touch screen computer-based neurocognitive test battery (IntegNeuro^®). Varenicline (1 mg twice daily) significantly improved performance in executive function and emotional recognition tasks. Our case reports describe no clinically significant adverse effects and suggest that varenicline improves aspects of cognitive function in patients with early HD. A randomized controlled study is now underway.

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.

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.

Genetic variation (CHRNA5), medication (combination nicotine replacement therapy vs. varenicline), and smoking cessation

OBJECTIVE

Recent evidence suggests that the efficacy of smoking cessation pharmacotherapy can vary across patients based on their genotypes. This study tests whether the coding variant rs16969968 in the CHRNA5 nicotinic receptor gene predicts the effects of combination nicotine replacement therapy (cNRT) and varenicline on treatment outcomes.

METHOD

In two randomized smoking cessation trials comparing cNRT vs. placebo, and varenicline vs. placebo, we used logistic regression to model associations between CHRNA5 rs16969968 and abstinence at end of treatment.

RESULTS

For abstinence at end of treatment, there was an interaction between cNRT and rs16969968 (X(2)=8.15, df=2, omnibus-p=0.017 for the interaction); individuals with the high-risk AA genotype were more likely to benefit from cNRT. In contrast, varenicline increased abstinence, but its effect did not vary with CHRNA5. However, the genetic effects differed between the placebo control groups across two trials (wald=3.94, df=1, p=0.047), this non-replication can alter the interpretation of pharmacogenetic findings.

CONCLUSIONS

Results from two complementary smoking cessation trials demonstrate inconsistent genetic results in the placebo arms. This evidence highlights the need to compare the most effective pharmacotherapies with the same placebo control to establish pharmacogenetic evidence to aid decisions on medication choice for patients trying to quit smoking.

Varenicline and risk of psychiatric conditions, suicidal behaviour, criminal offending, and transport accidents and offences: population based cohort study

OBJECTIVE

To examine associations between varenicline and the incidence of a range of adverse outcomes.

DESIGN

Population based cohort study using within person analyses to control for confounding by indication.

SETTING

Whole population of Sweden.

PARTICIPANTS

7,917,436 people aged 15 and over, of whom 69,757 were treated with varenicline between 2006 and 2009.

MAIN OUTCOME MEASURES

Incidence of new psychiatric conditions, suicidal behaviour, suspected and convicted criminal offending, transport accidents, and suspected and convicted traffic offences.

RESULTS

In the whole population, 337,393 new psychiatric conditions were diagnosed during follow-up. In addition, 507,823 suspected and 338,608 convicted crimes, 40,595 suicidal events, 124,445 transport accidents, and 99,895 suspected and 57,068 convicted traffic crimes were recorded. Within person analyses showed that varenicline was not associated with significant hazards of suicidal behaviour, criminal offending, transport accidents, traffic offences, or psychoses. However, varenicline was associated with a small increase in the risk of anxiety conditions (hazard ratio 1.23, 95% confidence interval 1.01 to 1.51) and mood conditions (1.31, 1.06 to 1.63), which was only seen in people with pre-existing psychiatric disorders.

CONCLUSIONS

Concerns that varenicline is associated with an increased risk of many adverse outcomes, including suicidality and accidents, are not supported in this observational study. The small increase in risk of two psychiatric conditions in people with pre-existing psychiatric disorders needs to be confirmed using other research designs.

Pharmacological Options for Smoking Cessation in Heavy-Drinking Smokers

There is a high prevalence of comorbid tobacco use and alcohol use disorder (AUD), affecting more than 6 million people in the US. Globally, tobacco and alcohol use rank fourth and fifth, respectively, for disability-adjusted life-years lost. Levels of alcohol use are higher in smokers than nonsmokers, and the prevalence of smoking is higher in heavy drinkers compared with nondrinkers. This relationship is driven by many different factors, including genetics, neurobiological mechanisms, conditioning processes, and psychosocial influences. Although this unique population tends to experience more negative health consequences, more severe AUD, and poorer response to treatment than those with either AUD or tobacco use disorder alone, there are currently no available treatment protocols tailored to this comorbid condition. In this review, we provide a comprehensive review of ongoing clinical research into smoking cessation options for heavy-drinking smokers (HDS) through an evaluation of the effect of promising novel pharmacotherapies as well as combination therapies, including varenicline, naltrexone, the combination of varenicline and naltrexone, and the combination of naltrexone and nicotine replacement therapy (NRT). These treatments are considered in light of the standard of care for smoking cessation, and seek to improve upon the available guidelines for this sizeable subgroup of smokers, namely those smokers who drink heavily.