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

Smoking cessation decreases arterial blood pressure in hypertensive smokers: A subgroup analysis of the randomized controlled trial GENTSMOKING

INTRODUCTION

High blood pressure in hypertensive smokers is affected by nicotine consumption. This study aimed to evaluate the effect of smoking cessation treatments on blood pressure in hypertensive smokers.

METHODS

A total of 113 hypertensive smokers on antihypertensives during smoking cessation treatment in the randomized controlled trial GENTSMOKING were considered for analysis. At Baseline (T0) and Week 12 (T12), systolic and diastolic blood pressure (SBP and DBP), and heart rate (HR) were measured using a semi-automated digital oscillometric device. Mean arterial pressure (MAP) and delta differences for SBP, DBP, HR, and MAP were calculated. Smoking cessation was confirmed by measuring carbon monoxide (CO) in exhaled air.

RESULTS

After 12 weeks of treatment, 72 participants ceased smoking (cessation group) and 41 did not (no cessation group). At T0, there was no statistically meaningful difference between groups with respect to age, body mass index, CO, and daily cigarette consumption. At T12, daily cigarette consumption and CO had decreased in both groups (p<0.001). The cessation group showed decreased SBP (131 ± 2 vs 125 ± 2 mmHg, p=0.004), DBP (79 ± 1 vs 77 ± 1 mmHg, p=0.031), MAP (96 ± 1 vs 93 ± 1 mmHg, p=0.005), and HR (79 ± 1 vs 74 ± 1 beats/min, p=0.001), and increased body weight (77.4 ± 2.1 vs 79.2 ± 2.2 kg, p<0.001). No significant differences were seen for these variables in the no cessation group. Decrease in blood pressure was significantly higher among hypertensive participants with SBP ≥130 mmHg: SBP (145 ± 2 vs 132 ± 2 mmHg, p<0.001), DBP (85 ± 2 vs 80 ± 1 mmHg, p=0.002), MAP (105 ± 1 vs 97 ± 1 mmHg, p<0.001), and HR (81 ± 2 vs 74 ± 2 beats/min, p=0.002). A positive correlation was found between HR and CO (r=0.34; p=0.001).

CONCLUSIONS

Smoking cessation treatment reduced blood pressure in hypertensive smokers, allowing them to reach therapeutic targets for hypertension management. Smoking cessation has a positive impact on hypertension treatment; therefore, it should be encouraged in clinical practice.

CLINICALTRIALSGOV IDENTIFIER

NCT03362099.

The utility of the self-controlled study design for pharmacoepidemiological studies without an active comparator medication using a medical information database: An application to assess the risk of varenicline on cardiovascular outcomes

PURPOSE

To illustrate the utility of the self-controlled study design for studies without an active comparator, we compared the results of a cohort design study with a non-user comparator with those of a self-controlled design study in evaluating the risk of varenicline on cardiovascular outcomes, using a Japanese medical claims database.

METHODS

The participating smokers were identified from health-screening results collected between May 2008 and April 2017. Using a non-user-comparator cohort study design, we estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) of varenicline on initial hospitalization with cardiovascular outcomes using Cox's model adjusted for patients' sex, age, medical history, medication history, and health-screening results. Using a self-controlled study design, the within-subject HR was estimated using a stratified Cox's model adjusted for medical history, medication history, and health-screening results. The estimate from a recent meta-analysis was considered the gold standard (risk ratio: 1.03).

RESULTS

We identified 460 464 smokers (398 694 males [86.6%]; mean (standard deviation) age: 42.9 [10.8] years) in the database. Of these, 11 561 had been dispensed varenicline at least once, and 4511 had experienced cardiovascular outcomes. The estimate of the non-user-comparator cohort study design exceeded the gold standard (HR [95% CI]: 2.04 [1.22-3.42]), whereas that of the self-controlled study design was close to the gold standard (within-subject HR [95% CI]: 1.12 [0.27-4.70]).

CONCLUSIONS

The self-controlled study design is useful alternative to a non-user-comparator cohort design when evaluating the risk of medications relative to their non-use, based on a medical information database.

Safety and Effectiveness of Varenicline in Korean Smokers: A Nationwide Post-Marketing Surveillance Study

PURPOSE

Varenicline has demonstrated its safety and efficacy in Western studies including <3% of Asian participants. This prospective multi-center observational study investigated the safety and effectiveness of varenicline in Korean smokers.

PATIENTS AND METHODS

Smokers prescribed varenicline for the first time were enrolled from 252 medical institutions. Investigators recorded and graded all adverse events (AEs). To assess the effectiveness of varenicline, the 7-day point prevalence (PP) of smoking cessation was evaluated at the four visits during the 12-week treatment course. Rates of AE incidence and smoking cessation were analyzed using Chi-squared test or Fisher's exact test. This study is registered with ClinicalTrials.gov, number NCT00483002.

RESULTS

A total of 3719 and 3700 study subjects were included in the safety and effectiveness analyses, respectively. Overall, 346 (9.3%) subjects experienced 471 AEs: 358 mild, 97 moderate, 9 severe, and 7 serious. The most frequent AEs were nausea (5.1%), dyspepsia (0.8%), abnormal dreams (0.8%), insomnia (0.8%), and headache (0.7%). Among the subjects with AEs, 73 subjects discontinued treatment, of which 68 were due to AE occurrence. The 7-day PP of smoking cessation at weeks 1-2, 3-6, 7-10, and ≥ week 11 were 51.7% (387/749), 59.6% (1740/2922), 73.3% (1114/1520), and 77.0% (1116/1449), respectively (p for trend = 0.023). Comorbidities and allergies were associated with a higher incidence of AEs and lower smoking cessation rate (p < 0.05). Younger subjects, infrequent alcohol drinkers, and lighter smokers showed a higher smoking cessation rate (p < 0.05).

CONCLUSION

Varenicline in adult Korean smokers was well tolerated and effective as a smoking cessation aid in routine clinical practice.

Comparison of Cardiovascular Safety for Smoking Cessation Pharmacotherapies in a Population-Based Cohort in Australia

IMPORTANCE

Although concerns exist regarding a potential increased risk of cardiovascular events for smoking cessation pharmacotherapies, there is general consensus that any increased risk associated with their use would be outweighed by the benefits of smoking cessation; thus, clinical guidelines recommend that such pharmacotherapies be offered to everyone who wants to quit smoking. In the interest of minimizing risk to patients, prescribers need evidence indicating how these pharmacotherapies compare with one another in terms of cardiovascular safety.

OBJECTIVE

To compare the risk of major adverse cardiovascular events (MACE) among individuals initiating varenicline, nicotine replacement therapy (NRT) patches, or bupropion.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, population-based cohort study using linked pharmaceutical dispensing, hospital admissions, and death data was conducted in New South Wales, Australia. Participants included adults who were dispensed a prescription smoking cessation pharmacotherapy between 2008 and 2015 or between 2011 and 2015, depending on the availability of the pharmacotherapies being compared. Pairwise comparisons were conducted for risk of MACE among 122 932 varenicline vs 92 148 NRT initiators; 342 064 varenicline vs 10 457 bupropion initiators; and 102 817 NRT vs 6056 bupropion initiators.

EXPOSURE

First course of the smoking cessation pharmacotherapy of interest.

MAIN OUTCOMES AND MEASURES

The primary outcome was MACE, defined as a composite of acute coronary syndrome, stroke, and cardiovascular death. Secondary outcomes were the individual components of MACE. Inverse probability of treatment weighting with high-dimensional propensity scores was used to account for potential confounding. Cox proportional hazards regression models with robust variance were used to estimate hazard ratios (HRs) and 95% CIs. Data were analyzed January 24, 2019, to September 1, 2021.

RESULTS

The mean (SD) age of included individuals ranged from 41.9 (14.2) to 49.8 (14.9) years, and the proportion of women ranged from 42.8% (52 702 of 123 128) to 52.2% (53 693 of 102 913). The comparison of 122 932 varenicline initiators and 92 148 NRT patch initiators showed no difference in the risk of MACE (HR, 0.87; 95% CI, 0.72-1.07) nor in the risk of the secondary outcomes of acute coronary syndrome (HR, 0.96; 95% CI, 0.76-1.21) and stroke (HR, 0.72; 95% CI, 0.45-1.14). However, decreased risk of cardiovascular death was found among varenicline initiators (HR, 0.49; 95% CI, 0.30-0.79). The results of comparisons involving bupropion were inconclusive owing to wide confidence intervals (eg, risk of MACE: 342 064 varenicline vs 10 457 bupropion initiators, HR, 0.87 [95% CI, 0.53-1.41]; 102 817 NRT patch vs 6056 bupropion initiators, HR, 0.79 [95% CI, 0.39-1.62]).

CONCLUSIONS AND RELEVANCE

The finding of this cohort study that varenicline and NRT patch use have similar risk of MACE suggests that varenicline, the most efficacious smoking cessation pharmacotherapy, may be prescribed instead of NRT patches without increasing risk of major cardiovascular events. Further large-scale studies of the cardiovascular safety of varenicline and NRT relative to bupropion are needed.

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

BACKGROUND

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

OBJECTIVES

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

DESIGN

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

SETTING

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

PARTICIPANTS

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

INTERVENTIONS

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

MAIN OUTCOME MEASURES

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

DATA SOURCES

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

REVIEW METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

FUTURE WORK

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

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041302.

FUNDING

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

Therapeutic concentrations of varenicline increases exocytotic release of catecholamines from human and rat adrenal chromaffin cells in the presence of nicotine

Cardiovascular side effects of varenicline and a case report of a hypertensive crisis in a varenicline-prescribed patient with pheochromocytoma have been reported. The goal of the present study was to determine whether such side effects might derive, in part, from increased exocytosis of secretory vesicles and subsequent catecholamine release triggered by varenicline in human chromaffin cells of the adrenal gland. In this study, we performed electrophysiological plasma membrane capacitance and carbon fiber amperometry experiments to evaluate the effect of varenicline on exocytosis and catecholamine release, respectively, at concentrations reached during varenicline therapy (100 nM). Experiments were conducted in the absence or presence of nicotine, at plasma concentrations achieved right after smoking (250 nM) or steady-state concentrations (110 nM), in chromaffin cells of the adrenal gland obtained from human organ donors. Cells were stimulated with short pulses (10 ms) of acetylcholine (ACh; 300 μM) applied at 0.2 Hz, in order to closer mimic the physiological situation at the splanchnic nerve-chromaffin cell synapse. In addition, rat chromaffin cells were used to compare the effects obtained in cells from a more readily available species. Varenicline increased the exocytosis of secretory vesicles in human and rat chromaffin cells in the presence of nicotine, effects that were not due to an increase of plasma membrane capacitance or currents triggered by the nicotinic agonists alone. These results should be considered in nicotine addiction therapies when varenicline is used.

Risk of neuropsychiatric and cardiovascular adverse events following treatment with varenicline and nicotine replacement therapy in the UK Clinical Practice Research Datalink: a case-cross-over study

BACKGROUND AND AIMS

Varenicline and nicotine replacement therapy (NRT) are the most commonly used medications to quit smoking. Given their widespread use, monitoring adverse risks remains important. This study aimed to estimate the neuropsychiatric and cardiovascular risks associated with varenicline and NRT as used in routine UK care.

DESIGN

Case-cross-over study.

SETTING

UK-based electronic primary care records in the Clinical Practice Research Datalink from 2006 to 2015 linked to hospital and mortality data sets.

PARTICIPANTS

Adult smokers (n =282,429) observed during periods when exposed and not exposed to either varenicline or NRT.

MEASUREMENTS

Main outcomes included suicide, self-harm, myocardial infarction (MI), all-cause death and cause-specific death [MI, chronic obstructive pulmonary disease (COPD)]. In primary analyses, conditional logistic regression was used to compare the chance of varenicline or NRT exposure during the risk period (90 days prior to the event) with the chance of exposure during an earlier single reference period (91-180 days prior to the event) or multiple 90-day reference periods to increase statistical power.

FINDINGS

In the primary analyses, findings were inconclusive for the associations between varenicline and the main outcomes using a single reference period, while NRT was associated with MI [odds ratio (OR) = 1.40, 95% confidence interval (CI) = 1.18-1.67]. Using multiple reference periods, varenicline was associated with an increased risk of self-harm (OR = 1.32, 95% CI = 1.12-1.56) and suicide (OR = 3.56, 95% CI = 1.32-9.60) but a reduction in all-cause death (OR = 0.75, 95% CI = 0.61-0.93). NRT was associated with MI (OR = 1.54, 95% CI = 1.36-1.74), self-harm (OR = 1.30, 95% CI = 1.18-1.44) and deaths from MI (OR = 1.53, 95% CI = 1.11-2.10), COPD (OR = 1.33, 95% CI = 1.14-1.56) and all causes (OR = 1.28, 95% CI = 1.18-1.40) when using multiple reference periods.

CONCLUSIONS

There appear to be positive associations between (1) nicotine replacement therapy (NRT) and myocardial infarction, death and risk of self-harm and (2) varenicline and increased risk of self-harm and suicide, as well as a negative association between varenicline and all-cause death. The associations may not be causal. They may reflect health changes at the time of smoking cessation (nicotine replacement therapy is prescribed for people with cardiac problems) or be associated with quit attempts (exposure to both medicines was associated with self-harm).

Comparative Safety of Smoking Cessation Pharmacotherapies During a Government-Sponsored Reimbursement Program

INTRODUCTION

The British Columbia Ministry of Health launched a Smoking Cessation Program on September 30, 2011, providing financial coverage for smoking cessation pharmacotherapies. Although pharmacotherapies have been shown to have a moderate short-term benefit as a quitting aid, substantial cardiovascular and neuropsychiatric safety concerns have been identified in adverse-reporting databases, leading to prescription label warnings by Health Canada and the U.S. Food and Drug Administration. However, recent studies indicate these warnings may be without merit. This study examined the comparative safety of medications commonly used to aid smoking cessation.

AIMS AND METHODS

Population-based retrospective cohort study using B.C. administrative data to assess the relative safety between varenicline, bupropion, and nicotine replacement therapies (NRTs). The primary outcome was a composite of cardiovascular hospitalizations. Secondary outcomes included mortality, a composite of neuropsychiatric hospitalizations, and individual components of the primary outcome. Statistical analysis used propensity score-adjusted log-binomial regression models. A sensitivity analysis excluded patients with a history of cardiovascular disease.

RESULTS

The study included 116 442 participants. Compared with NRT, varenicline was associated with a 10% 1-year relative risk decrease of cardiovascular hospitalization (adjusted risk ratio [RR] = 0.90, 95% confidence interval (CI): 0.82 to 1.00), a 20% 1-year relative risk decrease of neuropsychiatric hospitalization (RR: 0.80, CI: 0.7 to 0.89), and a 19% 1-year relative risk decrease of mortality (RR: 0.81, CI: 0.71 to 0.93). We found no significant association between NRT and bupropion for cardiovascular hospitalizations, neuropsychiatric hospitalizations, or mortality.

CONCLUSIONS

Compared with NRT, varenicline is associated with fewer serious adverse events and bupropion the same number of serious adverse events.

IMPLICATIONS

This study addresses the need for comparative safety evidence in a real-world setting of varenicline and bupropion against an active comparator. Compared with NRT, varenicline was associated with a decreased risk of mortality, serious cardiovascular events, and neuropsychiatric events during the treatment, or shortly after the treatment, in the general population of adults seeking pharmacotherapy to aid smoking cessation. These results provide support for the removal of the varenicline boxed warning for neuropsychiatric events and add substantively to the cardiovascular safety findings of previous observational studies and randomized clinical trials.

Smoking cessation: strategies and effects in primary and secondary cardiovascular prevention

Although smoking is seen as a major health problem by most clinicians, few are able to provide evidence based smoking cessation interventions to their patients. Most individuals who smoke actually want to quit. Unfortunately, smoking is still seen as a vice or lifestyle choice, when it is actually a chronic disease which often starts in adolescence. Nicotine dependence is complex and must be quantified and treated differently for each patient in order to achieve high quit rates. Smoking has a significant impact on the development and progression of cardiovascular disease. Smoking cessation is a cost effective and often overlooked prevention tool which improves both short- and long-term outcomes. There are both pharmacological and non-pharmacological strategies for smoking cessation that can be applied in clinical practice. Brief advice, specialized counseling including therapeutic education and behavioral support, and first- and second-line pharmacological interventions have been proven to be effective to help smokers quit. Although classically tobacco dependence was seen in relation to smoking, since the early 2000s, new nicotine delivery systems have appeared on the market, which despite being marketed as "healthy" alternatives, can often complicate smoking cessation efforts and act as gateway devices for new generations of smokers. In this article we review the results of several large systematic reviews and meta-analyses, which have shown that many cessation strategies are effective. We also offer practical tips on providing brief cessation advice and how pharmacotherapy can be prescribed and incorporated into clinical practice in both primary and secondary cardiovascular prevention.

Outcomes of deep brain stimulation surgery for substance use disorder: a systematic review

Long has the standard of care for substance use disorder (SUD) been pharmacotherapy, psychotherapy, or rehabilitation with varying success. Deep brain stimulation (DBS) may have a beneficial reduction in the addiction-reward pathway. Recent studies have found reduced relapse and improvements in quality of life following DBS stimulation of the nucleus accumbens. We aim to identify positive outcomes and adverse effects to assess the viability of DBS as a treatment of addiction. A PubMed search following PRISMA guidelines was conducted to identify the entirety of reports reporting DBS as a treatment for SUD. Outcomes were extracted from the literature to be summarized, and a review of the quality of publications was also performed. From 2305 publications, 14 studies were found to fit the inclusion criteria published between 2007 and 2019. All studies targeted the nucleus accumbens (NAc) and remission rates at 6 months, 1 year, 2 years, and more than 6 years were 61% (20/33), 53% (17/32), 43% (14/30), and 50% (3/6), respectively. Not all studies detailed the stimulation settings or coordinates. The most common adverse effect across studies was a weight change of at least 2 kg. DBS shows potential as a long-term treatment of SUD in refractory patients. Further studies with controlled double-blind paradigms are needed for evaluation of the efficacy and safety of this treatment. Future studies should also investigate other brain regions for stimulation and optimal device stimulation parameters.

Varenicline: mode of action, efficacy, safety and accumulated experience salient for clinical populations

Objective: Varenicline, a selective partial agonist of the α4β2 nicotinic acetylcholine receptor, is a smoking cessation pharmacotherapy that more than doubles the chance of quitting smoking at 6 months compared with placebo. This article reviews salient knowledge of the discovery, pharmacological characteristics, and the efficacy and safety of varenicline in general and in specific populations of smokers and provides recommendations to support use in clinical practice.Methods: Literature searches for varenicline were conducted using PubMed, with date limitations of 2000-2018 inclusive, using search terms covering the discovery, mechanism of action, pharmacokinetics, efficacy and safety in different populations of smokers, alternative quit approaches and combination therapy. Selection of safety and efficacy data was limited to clinical trials, meta-analyses and observational studies.Results: Standard administration of varenicline is efficacious in helping smokers to quit, including smokers with cardiovascular disease and chronic obstructive pulmonary disease. Furthermore, varenicline efficacy may be improved with pre-loading, a gradual quitting approach for smokers unwilling or unable to quit abruptly, and extended treatment in smokers who have recently quit to help maintain abstinence. Initial concerns regarding the association of varenicline with increased risk of neuropsychiatric and cardiovascular adverse events have been disproven after extensive clinical evaluations, and the benefit-risk profile of varenicline is considered favorable.Conclusions: Varenicline is efficacious and safe for all adult smokers with a range of clinical characteristics. Evidence suggests that approaches offering greater flexibility in timing and duration of treatment may further extend treatment efficacy and clinical reach.

Hesperidin blocks varenicline-aggravated atherosclerotic plaque formation in apolipoprotein E knockout mice by downregulating net uptake of oxidized low-density lipoprotein in macrophages

Varenicline is a widely used and effective drug for smoking cessation. We have previously reported experimental evidence suggesting that varenicline increases the risk of cardiovascular events. Varenicline progresses atherosclerotic plaque formation in apolipoprotein E knockout (ApoE KO) mice. This adverse effect is likely due to enhanced net uptake of oxidized low-density lipoprotein (oxLDL) in macrophages as a result of increased scavenger receptors and decreased cholesterol efflux transporters. However, a regimen has not yet been presented for avoidance or amelioration of the risk for varenicline-induced cardiovascular events. The aim of this study was to examine the effect of hesperidin, a citrus flavonoid, on varenicline-aggravated atherosclerotic plaque formation in apolipoprotein E knockout (ApoE KO) mice. Hesperidin inhibited the aggravating effect of varenicline in the whole aorta, aortic arch, and aortic root of ApoE KO mice. In addition, hesperidin protected against varenicline-enhanced oxLDL net uptake by blocking the increased expression of CD36 and LOX-1 scavenger receptors and decreased expression of ABCA1 and ABCG1 cholesterol efflux transporters in RAW 264.7 cells. Our findings suggest that hesperidin can avoid or ameliorate the risk for cardiovascular events induced by varenicline treatment.

Expression of α3β2β4 nicotinic acetylcholine receptors by rat adrenal chromaffin cells determined using novel conopeptide antagonists

Adrenal chromaffin cells release neurotransmitters in response to stress and may be involved in conditions such as post-traumatic stress and anxiety disorders. Neurotransmitter release is triggered, in part, by activation of nicotinic acetylcholine receptors (nAChRs). However, despite decades of use as a model system for studying exocytosis, the nAChR subtypes involved have not been pharmacologically identified. Quantitative real-time PCR of rat adrenal medulla revealed an abundance of mRNAs for α3, α7, β2, and β4 subunits. Whole-cell patch-clamp electrophysiology of chromaffin cells and subtype-selective ligands were used to probe for nAChRs derived from the mRNAs found in adrenal medulla. A novel conopeptide antagonist, PeIA-5469, was created that is highly selective for α3β2 over other nAChR subtypes heterologously expressed in Xenopus laevis oocytes. Experiments using PeIA-5469 and the α3β4-selective α-conotoxin TxID revealed that rat adrenal medulla contain two populations of chromaffin cells that express either α3β4 nAChRs alone or α3β4 together with the α3β2β4 subtype. Conclusions were derived from observations that acetylcholine-gated currents in some cells were sensitive to inhibition by PeIA-5469 and TxID, while in other cells, currents were sensitive only to TxID. Expression of functional α7 nAChRs was determined using three α7-selective ligands: the agonist PNU282987, the positive allosteric modulator PNU120596, and the antagonist α-conotoxin [V11L,V16D]ArIB. The results of these studies identify for the first time the expression of α3β2β4 nAChRs as well as functional α7 nAChRs by rat adrenal chromaffin cells.

Evaluation of reproductive and renal toxicity of varenicline in male rats

OBJECTIVES

Varenicline is a selective partial agonist for the nicotinic acetylcholine receptor a4b2 subtype, which is widely used to treat smoking addiction. However, there is still no data about its potential toxic effects on tissues. In this study, we aimed to determine the varenicline-induced toxicity on reproductive and renal tissues in rats.

MATERIALS AND METHODS

Rats were randomly divided into two groups: control (n=10) and varenicline (n=24). Then, rats in each group were sub-divided equally as acute and chronic groups. The control rats were orally given distilled water only. Varenicline was administrated orally as follows: 1^st-3^rd days 9 µg/kg/day, 4^th-7^th days 9 µg/kg twice daily, and 8^th-90^th days 18 µg/kg twice daily. The rats of acute and chronic groups were sacrificed on the 45^th and 90^th days, respectively. Some tissue markers related to oxidative stress were measured, and sperm characteristics were observed.

RESULTS

In the acute group, varenicline led to a significant decrease in SOD activities in both kidney and testis tissues. In the chronic group, varenicline significantly increased MDA and MPO production, and reduced CAT and GPx levels in the kidneys and testes. Also, SOD and GSH levels significantly decreased in the testes. Moreover, sperm characteristics were negatively affected; histopathological deformation was observed in the testes and kidneys in all groups.

CONCLUSION

This study showed that varenicline could detrimentally affect the kidneys and testes in both acute and chronic term usage. Further studies will provide more insights into the molecular dynamics of this damage.

Statistical controversies in clinical research: limitations of open-label studies assessing antiangiogenic therapies with regard to evaluation of vascular adverse drug events-a meta-analysis

Background

Previous meta-analyses have shown paradoxical increased risk of bleeding and thrombotic events in patients receiving antiangiogenics (AA) that may be simply explained by the studies design included. By a meta-epidemiological approach, we aim to investigate the impact of double-blind (DB) and open-label study designs on the risks of bleeding, venous thrombotic events (VTE) and arterial thrombotic events (ATE) in cancer patients treated with AA.

Materials and methods

We searched Medline, Cochrane, ClinicalTrials.gov databases and proceedings of major oncology congresses for clinical trials published from January 2003 to January 2016. Randomized clinical trials that assigned patients with solid cancers to AA or control groups were eligible for inclusion. Combined odds ratios (ORs) for the risks of bleeding events, VTE and ATE were calculated for open and DB trials. Estimation bias of the treatment effect was determined by the ratio of OR, by dividing the OR values obtained in open-label trials by those obtained in DB trials.

Results

The literature-based meta-analysis included 166 trials (72 024 patients). For bleeding events, comparison of AA versus control yielded an overall OR of 2.41 [95% confidence interval (95% CI) 2.12-2.73; P < 0.001], but this risk was overestimated by 1.68 (95% CI 1.33-2.13) in open-label studies. Concerning VTE, the OR was 1.19 (95% CI 1.04-1.35; P = 0.012) overall with AA, but this effect disappears when considering only DB trials (OR 0.99, 95% CI 0.83-1.17). The corresponding ratio of OR showed a significant overestimation of 1.53 (95% CI 1.19-1.96) in open-label trials. For ATE, an OR of 1.59 (95% CI 1.30-1.94; P < 0.001) was observed, associated with a significant overestimation of 1.65 (95% CI 1.13-2.43) in open-label trials.

Conclusions

Open-label studies overestimated the risk of vascular adverse events with AA by at least 50%. Meta-analyses assessing adverse drug events should therefore be restricted to DB randomized trials.

Varenicline aggravates atherosclerotic plaque formation in nicotine-pretreated ApoE knockout mice due to enhanced oxLDL uptake by macrophages through downregulation of ABCA1 and ABCG1 expression

Varenicline is a widely used and effective drug for smoking cessation. We previously reported that varenicline aggravates atherosclerosis in apolipoprotein E knockout (ApoE KO) mice. However, it remains unknown whether varenicline affects cardiovascular events in patients with nicotine addiction. Here, we examined the effect of varenicline on atherosclerotic plaque formation in nicotine-pretreated ApoE KO mice and oxidized low-density lipoprotein (oxLDL) uptake in nicotine-treated peritoneal macrophages. Varenicline caused significant progression of plaque formation in the whole aorta and aortic root and further accelerated the increased formation of a macrophage-rich plaque area in the aortic root in nicotine-pretreated ApoE KO mice. Varenicline (10 μM) enhanced oxLDL uptake in peritoneal macrophages. Furthermore, this treatment significantly further lowered the decreased protein levels of ATP-binding cassette (ABC) transporter without affecting the expression of scavenger receptors LOX-1 and CD36 in RAW264.7 cells treated with 100 nM nicotine. Varenicline enhanced nicotine-induced oxLDL uptake in macrophages through decreased expression of cholesterol efflux transporters ABCA1 and ABCG1 and thereby progressed atherosclerotic plaque formation. Taken together, we tentatively conclude that nicotine exposure before and/or during varenicline treatment can aggravate varenicline-increased atherosclerotic plaque formation and progression. Therefore, this enhanced risk requires special consideration when prescribing varenicline to smoker patients.

Combined nicotine patch with gum versus nicotine patch alone in smoking cessation in Hong Kong primary care clinics: a randomised controlled trial

Background

The prevalence of daily cigarette smoking has dropped to 10% in Hong Kong (HK) in 2017, however, smoking still kills 5700 persons per year. Studies suggest that abstinence rates are higher with combined NRT than single NRT, although local data on safety and benefits of combined NRT are lacking. The aim of this study is to compare the effectiveness of combined NRT with single NRT among HK Chinese.

Methods

This is a one-year, two-arm, parallel randomised trial. Five hundred sixty smokers, who smoked ≥10 cigarettes/day for ≥1 year, were randomized to combined and single NRT. Combined NRT group received counseling and nicotine patch & gum. Single NRT group received counselling and nicotine patch. Primary outcome was abstinence rate measured as self-reported 7-day point prevalence with CO validated at 52 weeks. Secondary outcomes included smoking abstinence rates at 4, 12, & 26 weeks. Crude odds ratio and p-value were reported from logistic regression without adjustment; for trend analysis, adjusted odds ratio (AOR) and p-value were reported from Generalized Estimating Equation (GEE) (controlling for time). All AORs were adjusted for age, sex, baseline CO and clusters.

Results

Abstinence rates at 4, 12, 26 and 52 weeks were all higher in the combined NRT group (35.8, 21.9, 16.8, 20.1%) compared with the single NRT group (28, 16.8, 11.2, 14.3%). At 4 weeks, combined NRT group was more likely to quit smoking (OR 1.43, 95% CI, 1.00 to 2.05) than the single NRT group. From GEE analysis, combined NRT group had a significantly higher abstinence rate (23.6%) than the single NRT group (17.6%) across repeated measures at all-time points. Combined NRT group was more likely to quit smoking (OR 1.43, 95% CI, 1.15 to 1.77). No significant difference in the side effect profile was detected between groups.

Conclusions

Smokers given 8 weeks of combined NRT were more likely to quit smoking at 4, 12, 26 and 52 weeks compared with single NRT. Combined NRT was as well tolerated as single NRT and it should be further promoted in our community.

Trial registration

NCT03836560 from ClinicalTrial.gov, 9 Feb 2019.

Treatment With Bupropion and Varenicline for Smoking Cessation and the Risk of Acute Cardiovascular Events and Injuries: a Swedish Case-Crossover Study

Introduction

Bupropion and varenicline are non-nicotine medications used for smoking cessation that mitigate craving and withdrawal symptoms. We aim to investigate whether these drugs increase the risk of selected acute adverse outcomes when used in medical practice.

Methods

Population-based case-crossover design using data from Swedish health and administrative registers. Adult individuals diagnosed with acute myocardial infarction, stroke, suicide, suicide attempt, fall injury, or that suffered a road traffic crash from 01.10.2006 for bupropion, or from 01.03.2008 for varenicline, until 31.12.2013 were included. Different lengths of exposure periods were analyzed within the 12-week hazard period prior to the adverse outcome (1-14, 15-28, and 29-84 days). The control period was matched using the interval preceding the hazard period (85-168 days), and breaking it up into equivalent periods (85-98, 99-112, and 113-168 days). Conditional logistic regression with each case considered as one stratum was used to estimate adjusted odds ratios (OR) and confidence intervals (CI).

Results

Neither medication was associated with consistent higher risks for any of the adverse outcomes. For bupropion and varenicline, respectively, in the 1-14 days hazard period, OR (95% CI) were: myocardial infarction 1.14 (0.55 to 2.34) and 1.06 (0.70 to 1.62); stroke 1.16 (0.39 to 3.47) and 1.26 (0.72 to 2.17), and traffic crashes 0.85 (0.39 to 1.85) and 1.48 (0.90 to 2.41). In the other periods, ORs were similar or even lower. For falls and suicidal events ORs were generally below one for both drugs.

Conclusion

The available evidence suggests that if prescription guidelines are properly followed regarding potential contraindications both of these medications could be considered relatively safe.

Implications

The reliable exposure and diagnosis assessment used in this nationwide register-based study, along with the number of cases gathered makes this sample one of the largest of its type to assess potential side effects associated with the use of these drugs. Neither medication was associated with consistent higher risks for any of the adverse outcomes studied.

Smoking abstinence 1 year after acute coronary syndrome: follow-up from a randomized controlled trial of varenicline in patients admitted to hospital

BACKGROUND

Patients who continue to smoke after acute coronary syndrome are at increased risk of reinfarction and death. We previously found use of varenicline to increase abstinence 24 weeks after acute coronary syndrome; here we report results through 52 weeks.

METHODS

The EVITA trial was a multicentre, double-blind, randomized, placebo-controlled trial of varenicline for smoking cessation in patients admitted to hospital with acute coronary syndrome. Participants were randomly assigned (1:1) to receive varenicline or placebo for 12 weeks, in conjunction with low-intensity counselling. Smoking abstinence was assessed via 7-day recall, with biochemical validation using exhaled carbon monoxide. Participants lost to follow-up or withdrawn were assumed to have returned to smoking.

RESULTS

Among the 302 participants, abstinence declined over the course of the trial, with 34.4% abstinent 52 weeks after acute coronary syndrome. Compared with placebo, point estimates suggest use of varenicline increased point-prevalence abstinence (39.9% v. 29.1%, difference 10.7%, 95% confidence interval [CI] 0.01% to 21.44%; number needed to treat 10), continuous abstinence (31.1% v. 21.2%, difference 9.9%, 95% CI -0.01% to 19.8%) and reduction in daily cigarette smoking by 50% or greater (57.8% v. 49.7%, difference 8.1%, 95% CI -3.1% to 19.4%). Varenicline and placebo groups had similar occurrence of serious adverse events (24.5% v. 21.9%, risk difference 2.7%, 95% CI -7.3% to 12.6%) and major adverse cardiovascular events (8.6% v. 9.3%, risk difference -0.7%, 95% CI -7.8% to 6.5%).

INTERPRETATION

Varenicline was efficacious for smoking cessation in this high-risk patient population. However, 60% of patients who received treatment with varenicline still returned to smoking. Trial registration: ClinicalTrials.gov, no. NCT00794573.

Big Health Data and Cardiovascular Diseases: A Challenge for Research, an Opportunity for Clinical Care

Cardiovascular disease (CVD) accounts for the majority of death and hospitalization, health care expenditures and loss of productivity in developed country. CVD research, thus, plays a key role for improving patients' outcomes as well as for the sustainability of health systems. The increasing costs and complexity of modern medicine along with the fragmentation in healthcare organizations interfere with improving quality care and represent a missed opportunity for research. The advancement in diagnosis, therapy and prognostic evaluation of patients with CVD, indeed, is frustrated by limited data access to selected small patient populations, not standardized nor computable definition of disease and lack of approved relevant patient-centered outcomes. These critical issues results in a deep mismatch between randomized controlled trials and real-world setting, heterogeneity in treatment response and wide inter-individual variation in prognosis. Big data approach combines millions of people's electronic health records (EHR) from different resources and provides a new methodology expanding data collection in three direction: high volume, wide variety and extreme acquisition speed. Large population studies based on EHR holds much promise due to low costs, diminished study participant burden, and reduced selection bias, thus offering an alternative to traditional ascertainment through biomedical screening and tracing processes. By merging and harmonizing large data sets, the researchers aspire to build algorithms that allow targeted and personalized CVD treatments. In current paper, we provide a critical review of big health data for cardiovascular research, focusing on the opportunities of this largely free data analytics and the challenges in its realization.

Evaluation of varenicline usage on ventricular repolarization after smoking cessation

BACKGROUND

Varenicline, which is a selective partial agonist of the alpha4-beta2 nicotinic acetylcholine receptor, is used for the smoking cessation pharmacotherapy. Cardiovascular adverse effects have been reported after varenicline usage in patients who stop smoking. We investigated the effect of varenicline usage on ventricular repolarization after smoking cessation.

METHODS

In this prospective cohort study, we evaluated the cardiac arrhythmic effects of varenicline by comparing smoking patients (n = 214) before and after varenicline usage. Varenicline administered patients were also compared to ex-smoker individuals (n = 50) who quit smoking without varenicline usage in terms of ventricular repolarization parameters.

RESULTS

After calculated according to Fridericia's and Framingham's formulas, QTc intervals were significantly increased when patients compared before and after smoking cessation with varenicline (402.9 ± 24.5 ms vs. 409.1 ± 25.0 ms p < 0.001 and 376.5 ± 15.2 ms, vs. 380.6 ± 13.5 ms; p < 0.001, respectively). There was no arrhythmic event during the follow-up. The change in Tp-e and QTc following varenicline usage was negatively correlated with the smoking packet/year. (ρ: -0.443, p < 0.001 and ρ = -0.601, p < 0.001) CONCLUSION: Varenicline usage was demonstrated to prolong ventricular repolarization parameters similar to animal studies. Varenicline may have a role to predispose cardiac dysrhythmias after utilization in smoking cessation.

Prevention and Treatment of Tobacco Use: JACC Health Promotion Series

Tobacco use is the leading preventable cause of death worldwide and is a major risk factor for cardiovascular disease (CVD). Both prevention of smoking initiation among youth and smoking cessation among established smokers are key for reducing smoking prevalence and the associated negative health consequences. Proven tobacco cessation treatment includes pharmacotherapy and behavioral support, which are most effective when provided together. First-line medications (varenicline, bupropion, and nicotine replacement) are effective and safe for patients with CVD. Clinicians who care for patients with CVD should give as high a priority to treating tobacco use as to managing other CVD risk factors. Broader tobacco control efforts to raise tobacco taxes, adopt smoke-free laws, conduct mass media campaigns, and restrict tobacco marketing enhance clinicians' actions working with individual smokers.

[Status of Evidence-based Medicine Education in Undergraduate Pharmacy Curricula]

　This research aimed to clarify the present status and challenges of evidence-based medicine (EBM) education in schools of pharmacy. We sent a questionnaire to 268 faculty members in August 2015, and a total of 192 were completed. The educational contents by respondents differed considerably. Only about 30% of respondents self-assessed the current EBM courses they taught as "fulfilling". Challenges such as "time deficits", "lack of exercise lessons and practical training", "limited awareness and skills of teachers", "lack of appropriate educational tools", and "insufficient academic ability of students" were mentioned.

[Interventions for smoking cessation in 2018]

Smoking cessation treatments have been proved effective to stop smoking. For pharmacological treatments, nicotine replacement therapies (NRT) as well as bupropion allow to increase 6 month-abstinence rates by more than 80% in comparison with placebo while varenicline prescription doubles success rates in the same conditions. These results mean that for 10 smokers who quit with placebo, 18 are expected to quit with NRT or bupropion and 28 are expected to quit with varenicline. Varenicline is 50% more effective than nicotine patch and 70% more effective than nicotine gum. Nevertheless, a combination including NRT patch and oral nicotine forms is as effective as varenicline, thus leading to encourage the prescription of a combination NRT when NRT are chosen. For these three pharmacological treatments, cardiovascular as well as neuropsychiatric tolerance were not found statistically different from placebo in randomized controlled trials. Yet, bupropion prescription leads to an increasing risk of seizure (1/1000 to 1/1500). For behavioral treatment, motivational interviewing as well as cognitive behavior therapies are been proven to be effective to stop smoking but few smokers have access to this treatment. Smoking cessation mobile application and smartphone application seem to be promising in terms of effectiveness and might be useful to reach more smokers.

Adverse events of smoking cessation treatments (nicotine replacement therapy and non-nicotine prescription medication) and electronic cigarettes in the Food and Drug Administration Adverse Event Reporting System, 2004-2016

Objectives:

Several smoking cessation treatments (nicotine replacement therapy and non-nicotine prescription medication) and electronic cigarettes are widely used. We evaluated the adverse events related to smoking cessation treatments and electronic cigarettes in the US Food and Drug Administration Adverse Event Reporting System database.

Methods:

We analyzed reports of adverse events associated with smoking cessation treatment and electronic cigarettes terms dated between January 2004 and December 2016. We used the reporting odds ratio with 95% confidence intervals to detect a signal for each adverse event.

Results:

In total, 8,867,135 reports in the Food and Drug Administration Adverse Event Reporting System database were analyzed. The numbers of adverse events for nicotine replacement therapy (transdermal, buccal, oral, and respiratory administration) were 1673, 1016, 425, and 56, respectively. Nicotine replacement therapy (transdermal, buccal, and oral) demonstrated adverse events of nausea, nicotine dependence, and dizziness. For nicotine (transdermal) exposure, the top 5 adverse events reported were nausea (149 cases, reporting odds ratio: 2.28 (95% confidence interval: 1.92–2.69)), dizziness (132 cases, reporting odds ratio: 3.04 (95% confidence interval: 2.54–3.63)), application site erythema (108 cases, reporting odds ratio: 32.52 (95% confidence interval: 26.74–39.55)), headache (98 cases, reporting odds ratio: 1.84 (95% confidence interval: 1.50–2.25)), and dyspnea (94 cases, reporting odds ratio: 1.93 (95% confidence interval: 1.57–2.38)). Many cases of improper use of nicotine replacement therapies were reported. Nausea, depression, abnormal dreams, insomnia, and other adverse events were reported for varenicline. Insomnia, rash, anxiety, and dizziness were reported for bupropion. We observed electronic cigarettes–related adverse events such as dizziness, dyspnea, nausea, heart rate increased, and tremor.

Conclusion:

Our findings suggest that an association exists between nicotine-related adverse events and nicotine replacement therapy. Healthcare professionals should closely monitor smokers trying to quit nicotine use for the misuse of nicotine replacement therapy. These findings may be informative to healthcare professionals in order to improve the management of smoking cessation treatment.

Smoking Cessation in Patients With Acute Coronary Syndrome

Over 30% of the nearly 1 million North Americans hospitalized annually with an acute coronary syndrome (ACS) are smokers. Despite a substantially increased risk of morbidity and mortality, 2/3 of patients who quit smoking after ACS return to smoking within 1 year. To summarize the evidence of smoking cessation in patients hospitalized after ACS, we systematically reviewed all randomized controlled trials of pharmacologic and behavioral smoking cessation therapies in patients with ACS. In addition, we reviewed the clinical considerations surrounding the use of smoking cessation therapies, including their broad mechanisms of action and possible alternative treatments, including cardiac rehabilitation programs and electronic cigarettes. A total of 7 randomized controlled trials met our inclusion criteria (4 pharmacotherapies and 3 behavioral therapies). In pharmacologic trials, only varenicline increased point prevalence abstinence at 12 months. Behavioral interventions produced significantly improved abstinence rates at 6 and 12 months. However, these studies had substantial limitations affecting their generalizability. Overall, currently available smoking cessation therapies are limited in their efficacy in patients hospitalized after ACS. Because of the relative scarcity of data and the urgency of establishing clinical guidelines, there is a critical need to continue examining the efficacy and safety of smoking cessation interventions in patients hospitalized after ACS.

Human nicotinic receptors in chromaffin cells: characterization and pharmacology

During the last 10 years, we have been working on human chromaffin cells obtained from the adrenal gland of organ donors that suffered encephalic or cardiac death. We first electrophysiologically characterized the nicotinic acetylcholine receptors (nAChRs) activated by acetylcholine, and their contribution to the exocytosis of chromaffin vesicles and release of catecholamines. We have shown that these cells possess an adrenergic phenotype. This phenotype may contribute to an increased expression of α7 nAChRs in these cells, allowing for recording of α7 nAChR currents, something that had previously not been achieved in non-human species. The use of α-conotoxins allowed us to characterize non-α7 nAChR subtypes and, together with molecular biology experiments, conclude that the predominant nAChR subtype in human chromaffin cells is α3β4* (asterisk indicates the posible presence of additional subunits). In addition, there is a minor population of αxβ2 nAChRs. Both α7 and non-α7 nAChR subtypes contribute to the exocytotic process. Exocytosis mediated by nAChRs could be as large in magnitude as that elicited by calcium entry through voltage-dependent calcium channels. Finally, we have also investigated the effect of nAChR-targeted tobacco cessation drugs on catecholamine release in chromaffin cells. We have concluded that at therapeutic concentrations, varenicline alone does not increase the frequency of action potentials evoked by ACh. However, varenicline in the presence of nicotine does increase this frequency, and thus, in the presence of both drugs, the probability of increased catecholamine release in human chromaffin cells is high.

Cardiovascular and neuropsychiatric risks of varenicline and bupropion in smokers with chronic obstructive pulmonary disease

BACKGROUND

Varenicline and bupropion are effective smoking cessation treatments, but there are concerns about their safety in smokers with COPD.

OBJECTIVE

To investigate whether varenicline and bupropion are associated with serious adverse cardiovascular and neuropsychiatric events in smokers with COPD.

METHODS

In a retrospective cohort study, we used data from 14 350 patients with COPD included in the QResearch database, which holds data from 753 National Health Service general practices across England. We identified patients with COPD who received a prescription of nicotine replacement therapy (NRT; N=10 426; reference group), bupropion (N=350) or varenicline (N=3574) in the period between January 2007 and June 2012. Patients were followed up for 6 months to compare incident cardiovascular (ie, ischaemic heart disease, stroke, heart failure, peripheral vascular disease and cardiac arrhythmias) and neuropsychiatric (ie, depression and self-harm) events using Cox proportional hazards models, adjusted for potential confounders. Propensity score analysis was used as an additional approach to account for potential confounding by indication. We also modelled the effects of possible unmeasured confounders.

RESULTS

Neither bupropion nor varenicline showed an increased risk of adverse events compared with NRT. Varenicline was associated with a significantly reduced risk of heart failure (HR=0.56, 95% CI 0.34 to 0.92) and depression (HR=0.73, 95% CI 0.61 to 0.86). Similar results were obtained from the propensity score analysis. Modelling of unmeasured confounding provided additional evidence that an increased risk of these adverse events was very unlikely.

CONCLUSION

In smokers with COPD, varenicline and bupropion do not appear to be associated with an increased risk of cardiovascular events, depression or self-harm in comparison with NRT.

Interventions for smoking cessation in patients admitted with Acute Coronary Syndrome: a review

Tobacco smoking contributes to about six million deaths per year and is predicted to increase in the future. Several pharmacological interventions are used for smoking cessation. Trials using nicotine replacement therapy (NRT) in acute coronary syndrome (ACS) showed inconclusive results. Furthermore, three trials using bupropion in patients admitted with ACS failed to show improvement in smoking cessation compared with placebo. Interestingly, only one trial using varenicline was successful in achieving smoking abstinence in the acute setting. With regard to behavioural interventions, a meta-analysis found that telephone counselling was successful in both the acute and stable settings, with greater effect in the acute setting. The best results for smoking cessation were found in trials that used a combination of pharmacological and behavioural interventions. The objective of this report is to review the results of studies on interventions used for smoking cessation after an ACS.

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.

Therapeutic concentrations of varenicline in the presence of nicotine increase action potential firing in human adrenal chromaffin cells

Varenicline is a nicotinic acetylcholine receptor (nAChR) agonist used to treat nicotine addiction, but a live debate persists concerning its mechanism of action in reducing nicotine consumption. Although initially reported as α4β2 selective, varenicline was subsequently shown to activate other nAChR subtypes implicated in nicotine addiction including α3β4. However, it remains unclear whether activation of α3β4 nAChRs by therapeutically relevant concentrations of varenicline is sufficient to affect the behavior of cells that express this subtype. We used patch-clamp electrophysiology to assess the effects of varenicline on native α3β4* nAChRs (asterisk denotes the possible presence of other subunits) expressed in human adrenal chromaffin cells and compared its effects to those of nicotine. Varenicline and nicotine activated α3β4* nAChRs with EC₅₀ values of 1.8 (1.2-2.7) μM and 19.4 (11.1-33.9) μM, respectively. Stimulation of adrenal chromaffin cells with 10 ms pulses of 300 μM acetylcholine (ACh) in current-clamp mode evoked sodium channel-dependent action potentials (APs). Under these conditions, perfusion of 50 or 100 nM varenicline showed very little effect on AP firing compared to control conditions (ACh stimulation alone), but at higher concentrations (250 nM) varenicline increased the number of APs fired up to 436 ± 150%. These results demonstrate that therapeutic concentrations of varenicline are unlikely to alter AP firing in chromaffin cells. In contrast, nicotine showed no effect on AP firing at any of the concentrations tested (50, 100, 250, and 500 nM). However, perfusion of 50 nM nicotine simultaneously with 100 nM varenicline increased AP firing by 290 ± 104% indicating that exposure to varenicline and nicotine concurrently may alter cellular behavior such as excitability and neurotransmitter release.

New Pharmacological Agents to Aid Smoking Cessation and Tobacco Harm Reduction: What Has Been Investigated, and What Is in the Pipeline?

A wide range of support is available to help smokers to quit and to aid attempts at harm reduction, including three first-line smoking cessation medications: nicotine replacement therapy, varenicline and bupropion. Despite the efficacy of these, there is a continual need to diversify the range of medications so that the needs of tobacco users are met. This paper compares the first-line smoking cessation medications with (1) two variants of these existing products: new galenic formulations of varenicline and novel nicotine delivery devices; and (2) 24 alternative products: cytisine (novel outside Central and Eastern Europe), nortriptyline, other tricyclic antidepressants, electronic cigarettes, clonidine (an anxiolytic), other anxiolytics (e.g. buspirone), selective serotonin reuptake inhibitors, supplements (e.g. St John's wort), silver acetate, Nicobrevin, modafinil, venlafaxine, monoamine oxidase inhibitors (MAOIs), opioid antagonists, nicotinic acetylcholine receptor (nAChR) antagonists, glucose tablets, selective cannabinoid type 1 receptor antagonists, nicotine vaccines, drugs that affect gamma-aminobutyric acid (GABA) transmission, drugs that affect N-methyl-D-aspartate (NMDA) receptors, dopamine agonists (e.g. levodopa), pioglitazone (Actos; OMS405), noradrenaline reuptake inhibitors and the weight management drug lorcaserin. Six 'ESCUSE' criteria-relative efficacy, relative safety, relative cost, relative use (overall impact of effective medication use), relative scope (ability to serve new groups of patients) and relative ease of use-are used. Many of these products are in the early stages of clinical trials; however, cytisine looks most promising in having established efficacy and safety with low cost. Electronic cigarettes have become very popular, appear to be efficacious and are safer than smoking, but issues of continued dependence and possible harms need to be considered.

Effects of varenicline on sympatho-vagal balance and cue reactivity during smoking withdrawal: a randomised placebo-controlled trial

Background

Varenicline is an effective smoking cessation medication. Some concern has been raised that its use may precipitate adverse cardiovascular events although no patho-physiological mechanism potentially underlying such an effect has been reported. The aim of this study was to test the hypothesis that varenicline impacts on sympatho-vagal balance during smoking withdrawal.

Methods

In this randomised, placebo-controlled trial, muscle sympathetic nerve activity (MSNA), baroreflex sensitivity (BRS), heart rate, and blood pressure were assessed in 17 smokers four weeks before a quit attempt (baseline) and again on the third day of that quit attempt (acute smoking withdrawal).

Results

Regarding the primary endpoint of our study, we did not find a significant effect of varenicline compared to placebo on changes in MSNA burst incidence between baseline and acute smoking withdrawal (−3.0 ± 3.3 vs.−3.9 ± 5.0 bursts/100 heart beats; p = 0.308). However, heart rate and systolic blood pressure significantly decreased in the placebo group only, while no significant changes in these parameters were observed in the varenicline group. Exposure to smoking cues during acute withdrawal lead to a significant increase of heart rate in the placebo group, while heart rate decreased in the varenicline group, and the difference in these changes was significant between groups (+2.7 ± 1.0 vs.−1.8 ± 0.5 1/min; p = 0.002). In all 17 participants combined, a significant increase in heart rate during smoking cue exposure was detected in subjects who relapsed in the course of six weeks after the quit date compared to those who stayed abstinent (+2.5 ± 1.2 vs.−1.1 ± 0.7; p = 0.018). Six-week abstinence rates were higher in the varenicline group compared to placebo (88 vs. 22 % p = 0.015).

Conclusion

We did not find evidence of adverse effects of varenicline on sympatho-vagal balance. Varenicline probably blunts the heart rate response to smoking cues, which may be linked to improved cessation outcome.

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.

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 and Adverse Cardiovascular Events: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Varenicline is an efficacious smoking‐cessation drug. However, previous meta‐analyses provide conflicting results regarding its cardiovascular safety. The publication of several new randomized controlled trials (RCTs) provides an opportunity to reassess this potential adverse drug reaction.

Methods and Results

We searched MEDLINE, EMBASE, and the Cochrane Library for RCTs that compare varenicline with placebo for smoking cessation. RCTs reporting cardiovascular serious adverse events and/or all‐cause mortality during the treatment period or within 30 days of treatment discontinuation were eligible for inclusion. Relative risks (RRs) with 95% CIs were generated by using DerSimonian–Laird random‐effects models. Thirty‐eight RCTs met our inclusion criteria (N=12 706). Events were rare in both varenicline (57/7213) and placebo (43/5493) arms. No difference was observed for cardiovascular serious adverse events when comparing varenicline with placebo (RR 1.03, 95% CI 0.72–1.49). Similar findings were obtained when examining cardiovascular (RR 1.04, 95% CI 0.57–1.89) and noncardiovascular patients (RR 1.03, 95% CI 0.64–1.64). Deaths were rare in both varenicline (11/7213) and placebo (9/5493) arms. Although 95% CIs were wide, pooling of all‐cause mortality found no difference between groups (RR 0.88, 95% CI 0.50–1.52), including when stratified by participants with (RR 1.24, 95% CI 0.40–3.83) and without (RR 0.77, 95% CI 0.40–1.48) cardiovascular disease.

Conclusions

We found no evidence that varenicline increases the rate of cardiovascular serious adverse events. Results were similar among those with and without cardiovascular disease. Given varenicline's efficacy as a smoking cessation drug and the long‐term cardiovascular benefits of cessation, it should continue to be prescribed for smoking cessation.

Exploring Issues of Comorbid Conditions in People Who Smoke

Smoking affects comorbid disease outcomes, and patients with comorbid conditions may have unique characteristics that are important to consider when treating tobacco use. However, addressing tobacco in patients being treated for comorbid conditions is not a consistent practice. Recognizing the need for a "call-to-action" to address tobacco use in people with comorbid conditions, the Tobacco Treatment Network within the Society for Research on Nicotine and Tobacco (SRNT) convened a Comorbidities Workgroup to explore the relationship between smoking and comorbid disease to identify common themes including: the harms associated with continued tobacco use, the frequency of comorbid disease and tobacco use, the potential effect of comorbid disease on the ability to quit tobacco use, the association between tobacco use and suboptimal disease-specific treatment response, and evidence regarding potential approaches to improve addressing tobacco use in patients with comorbid disease. Five candidate conditions (psychiatric, cancer, cardiovascular, pulmonary, and human immunodeficiency virus infected patients) were explored. Across comorbid conditions, smoking adversely affects treatment efficacy and promotes other adverse health conditions. People with comorbid conditions who smoke are motivated to quit and respond to evidence-based smoking cessation treatments. However, tobacco cessation is not regularly incorporated into the clinical care of many individuals with comorbidities. Optimal strategies for addressing tobacco use within each comorbid disease are also not well defined. Further work is needed to disseminate evidence-based care into clinical practice for smokers with comorbid disease and addiction research should consider comorbid conditions as an important construct to explore.

IMPLICATIONS

This article explores how physical and psychiatric conditions may interact in the treatment of tobacco dependence, and discusses the need for smoking cessation as a critical component of comorbid condition management. Five common comorbid domains-psychiatric, cancer, pulmonary, cardiovascular, and human immunodeficiency virus (HIV)-are highlighted to illustrate how these different conditions might interact with smoking with respect to prevalence and harm, motivation to quit, and cessation treatment utilization and success.

Varenicline for Smoking Cessation in Hospitalized Patients With Acute Coronary Syndrome

Background—

Less than one-third of smokers hospitalized with an acute coronary syndrome (ACS) remain abstinent following discharge. We assessed whether varenicline, begun in-hospital, is efficacious for smoking cessation following ACS.

Methods and Results—

We conducted a multi-center, double-blind, randomized, placebo-controlled trial in which smokers hospitalized with an ACS were randomized to varenicline or placebo for 12 weeks. All patients received low-intensity counseling. The primary end point was point-prevalence smoking abstinence assessed at 24 weeks by 7-day recall and biochemical validation using expired carbon monoxide. A total of 302 patients were randomized (mean age 55±9 years; 75% male; 56% ST-segment elevation myocardial infarction; 38% non-ST-segment elevation myocardial infarction; 6% unstable angina). Patients smoked a mean of 21±11 cigarettes/d at the time of hospitalization and had been smoking for a mean of 36±12 years. At 24 weeks, patients randomized to varenicline had significantly higher rates of smoking abstinence and reduction than patients randomized to placebo. Point-prevalence abstinence rates were 47.3% in the varenicline group and 32.5% in the placebo group ( P =0.012; number needed to treat=6.8). Continuous abstinence rates were 35.8% and 25.8%, respectively ( P =0.081; number needed to treat=10.0), and rates of reduction ≥50% in daily cigarette consumption were 67.4% and 55.6%, respectively ( P =0.05; number needed to treat=8.5). Adverse event rates within 30 days of study drug discontinuation were similar between groups (serious adverse events: varenicline 11.9%, placebo 11.3%; major adverse cardiovascular events: varenicline 4.0%, placebo 4.6%).

Conclusions—

Varenicline, initiated in-hospital following ACS, is efficacious for smoking cessation. Future studies are needed to establish safety in these patients.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00794573.

Influence of smoking cessation drugs on blood pressure and heart rate in patients with cardiovascular disease or high risk score: real life setting

Background

Smoking is the most important reversible cardiovascular risk factor. It is well established that quitting smoking reduces coronary events. However, on several occasions, the cardiovascular safety of smoking cessation drugs has been questioned. Our goal is to evaluate the effects of smoking cessation drugs on blood pressure and heart rate in patients from a smoking cessation service in a cardiology hospital.

Methods

We examined the PAF database (Smoking Cessation Assistance Program database) between January 2008 and March 2014. We analyzed data from 900 patients who were compliant with the treatment (50.5 % male, average age 53 ± 17 years). The most frequent clinical diagnoses were coronary artery disease (25.2 %), hypertension (57.2 %), and diabetes (13.4 %). Blood pressure, heart rate, and carbon monoxide (CO) concentration in exhaled air were analyzed at consecutive visits during the first 45 days of treatment (mean visits - 3). Analysis of repeated measures was used for the statistical analysis (p < 0.05).

Results

Two hundred seventy one patients used nicotine replacement therapy (NRT) alone, 81 used bupropion alone, 154 used varenicline alone, 283 used NRT plus bupropion and 111 used bupropion plus varenicline. For all smoking cessation drugs, used alone or in combination, no increase occurred in the average value of systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR). Significant reductions in CO concentrations occurred in all smoking cessation drug groups.

Conclusion

Smoking cessation drugs used in monotherapy or in combined regimens did not influence systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) in this group of patients during the observation period.