Varenicline improves cognitive impairment in a mouse model of mPFC ischemia: The possible roles of inflammation, apoptosis, and synaptic factors.

Ischemia in the medial prefrontal cortex (mPFC) causes cognitive impairment in stroke cases. This study aimed to examine the effects of varenicline as α7 and α4ß2 nicotine acetylcholine receptors (nAChRs) agonist, on cognitive impairment, inflammation, apoptosis, and synaptic dysfunction in mPFC ischemia. Mice were divided to three groups of control, sham, or photothrombotic mPFC ischemia model. The control and sham groups received 2 ml/kg of normal saline for a 14-day period. As well, the animals in the ischemia groups received normal saline (2 ml/kg) or varenicline at 0.1, 1, and 3 mg/kg doses for a 14-day period. Anxiety-like behaviors were then assessed by open field (OFT) and elevated plus-maze (EPM) tests. Memory was also evaluated using Morris water maze (MWM) and novel object recognition (NOR) tests. The levels of inflammatory (IL-1ß, TNF-α), apoptotic (Bax, caspase3, BCL-2), and synaptic (SYP, PSD-95, and GAP-43) proteins were examined using the western blot method. In addition, the histological evaluation was performed to assess tissue damage. The administration of Varenicline at the dose of 3 mg/kg reduced the IL-1ß, TNF-α, Bax, and caspase3 levels. Moreover, it increased BCL-2, SYP, PSD-95, and GAP-43 levels at the same dose and ameliorated memory impairment and anxiety-like behaviors in mPFC ischemic mice. Varenicline improved cognitive impairment by blocking inflammation and apoptosis, improving synaptic factors, and diminishing tissue damage in the mPFC ischemic mice.

Frequently Reported Adverse Events With Smoking Cessation Medications: Post Hoc Analysis of a Randomized Trial.

OBJECTIVE: To compare the incidence, severity, and clinical course of frequently reported adverse events (AEs) after treatment with smoking cessation pharmacotherapies. METHODS: This was a multinational, multicenter, post hoc analysis of frequently reported treatment-emergent AEs from a large, phase 4, double-blind, randomized, triple-dummy, placebo-controlled trial (EAGLES), conducted between November 30, 2011, and January 13, 2015, that included smokers with and without psychiatric disorders (N=8144). Treatments were varenicline 1 mg twice daily, bupropion sustained-release 150 mg twice daily, and nicotine patch 21 mg once daily with tapering (12-week treatment, 12-week nontreatment follow-up), with incidence, time to onset, and duration of frequently reported AEs (≥5% of participants in any treatment group) measured. Risk differences for AEs for varenicline and bupropion vs nicotine patch were compared. RESULTS: Across frequently reported AEs, nausea, insomnia, abnormal dreams, anxiety, irritability, dry mouth, fatigue, and application site pruritus differed significantly in active treatment vs placebo groups. Risk differences were as follows: for nausea with varenicline vs nicotine patch, 15.50% (95% CI, 13.20% to 17.80%); for insomnia with bupropion vs nicotine patch, 2.58% (CI, 0.65% to 4.51%); and for abnormal dreams with varenicline and bupropion vs nicotine patch, -2.49% (CI, -4.35% to -0.64%) and -5.60% (CI, -7.27% to -3.93%), respectively. Frequently reported AEs of severe intensity and treatment discontinuation were experienced by less than 1.5% and less than 3% of participants across all groups, respectively. CONCLUSION: Active treatments were well tolerated with comparable AE profiles. Most AEs are not clinically important, and prescribers can reassure patients that those experienced will be manageable. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT01456936.

Varenicline rescues nicotine-induced decrease in motivation for sucrose reinforcement.

Varenicline is one of the top medications used for smoking cessation and is often prescribed before termination of nicotine use. The effect of this combined nicotine and varenicline use on the reward system and motivation for primary reinforcement is underexplored. The goal of this study was to assess the effects of nicotine and varenicline on motivation for a food reinforcer. In Experiment 1, we first assessed the responding for sucrose after pretreatment with nicotine (0, 0.1, or 0.4 mg/kg) and varenicline (0.0, 0.1, 1.0 mg/kg) using a behavioral economics approach. The responding for sucrose was then assessed using a progressive ratio schedule of reinforcement after pretreatment with all possible combinations of nicotine and varenicline doses. In Experiment 2, rats were assessed for the consumption of sucrose in home cages after pretreatment with nicotine and varenicline. We found that (a) nicotine decreased economic demand for sucrose, (b) varenicline rescued nicotine-induced reduction in economic demand for sucrose, and (c) history of varenicline treatment predicted responding for sucrose on a progressive ratio schedule of reinforcement where rats with a history of varenicline treatment responded significantly lower for sucrose across nicotine doses than rats that had not been exposed to varenicline. The results of Experiment 2 largely confirmed that nicotine decreases motivation for sucrose using a passive consumption protocol and that varenicline rescues this effect. Overall, these findings suggest that varenicline interacts with the effects of nicotine by restoring nicotine-induced reduction in motivation for appetitive rewards.

Varenicline enhances the survival of doxorubicin-treated mice.

OBJECTIVE: Doxorubicin (DOX) is widely used to treat various types of cancer. However, DOX treatment increases oxidative stress and causes other undesirable effects, such as cardiotoxicity, cognitive impairment, and death. Nicotine has been shown to inhibit DOX-induced cytotoxicity in vitro by activating nicotinic acetylcholine receptors. This study aimed to investigate whether combined treatment with varenicline, a partial agonist of nicotinic acetylcholine receptors, increased the survival rate of DOX-treated mice. MATERIALS AND METHODS: Forty male albino mice were divided into four groups of 10. Control-group mice received a single intraperitoneal (i.p.) injection of 0.9% saline. The DOX group received a single dose of DOX (20 mg/kg body weight, i.p.). The varenicline group received varenicline daily in their drinking water at 0.1 mg/mL. The DOX+varenicline group received a single dose of DOX (20 mg/kg body weight, i.p.) and daily administration of varenicline in their drinking water (0.1 mg/mL). Mice were observed daily to evaluate the survival rate, and their body weight was recorded on alternate days. RESULTS: All mice treated only with DOX died within 8 days. Co-administration of varenicline with DOX slightly improved the survival time and rate compared with the DOX-only group. CONCLUSIONS: Combined treatment with varenicline and DOX may be useful for improving survival relative to treatment with DOX alone. This may be because varenicline is an α7-nicotinic acetylcholine receptor agonist; however, further research into its precise mechanism of action is required.

High-dose and low-dose varenicline for smoking cessation in adolescents: a randomised, placebo-controlled trial.

BACKGROUND: Although cigarette smoking typically begins in adolescence, evidence for successful pharmacological smoking cessation interventions for this population is scarce. In adult smokers, varenicline is the most effective single pharmacotherapy. The aim of this study was to assess the efficacy and tolerability of varenicline for smoking cessation in adolescents. METHODS: We did a randomised, placebo-controlled trial with adolescent smokers aged 12-19 years who were seeking treatment to quit at 57 outpatient centres (in the USA, Russia, South Korea, Taiwan, Canada, and Georgia). Participants were randomly assigned (1:1:1) to receive 12 weeks of high-dose varenicline (1 mg twice daily; 0·5 mg twice daily if bodyweight ≤55 kg), low-dose varenicline (0·5 mg twice daily; 0·5 mg once daily if bodyweight ≤55 kg), or placebo, then followed up for 40 additional weeks. At all visits, participants received brief, developmentally tailored smoking cessation counselling (<10 min per session) delivered by a trained counsellor. The primary efficacy outcome was continuous abstinence from weeks 9 to 12, measured via a Nicotine Use Inventory and confirmed by urine cotinine testing. The primary tolerability outcome was frequency of treatment-emergent adverse events, including neuropsychiatric adverse events, occurring after the first dose and within 30 days of the last dose of study medication. This trial is registered with ClinicalTrials.gov, NCT01312909. FINDINGS: Between April 26, 2011, and Jan 18, 2018, 312 participants were enrolled and completed participation in the study: 109 in the high-dose varenicline group, 103 in the low-dose varenicline group, and 100 in the placebo group. The continuous abstinence rates from week 9 to 12 were 20% (22 of 109) in the high-dose varenicline group, 27% (28 of 103) in the low-dose varenicline group, and 18% (18 of 100) in the placebo group. Abstinence rates between high-dose varenicline and placebo groups (odds ratio [OR] 1·18 [95% CI 0·59-2·37]; p=0·63) and between low-dose varenicline and placebo groups (1·73 [0·88-3·39]; p=0·11) did not differ significantly. Treatment-emergent adverse events occurred in 65 (60%) of 108 participants in the high-dose group, 53 (53%) of 100 in the low-dose group, and 52 (53%) of 99 in the placebo group, and most were rated as mild. Neuropsychiatric treatment-emergent adverse events occurred in 18 (17%) of 108 participants in the high-dose group, 11 (11%) of 100 in the low-dose group, and 12 (12%) of 99 in the placebo group, and none was rated as severe. INTERPRETATION: This trial did not show an advantage in abstinence with varenicline compared with placebo among adolescent smokers. The rates of treatment-emergent adverse events were similar to those in previous trials of adult smokers, raising no new tolerability signals. These findings do not support the use of varenicline as a first-line pharmacotherapy for smoking cessation in adolescents. FUNDING: Pfizer.

Pharmacovigilance Assessment of Cardiac Implications of Nicotine Replacement Therapy Among Smokers.

PURPOSE: The purpose of this quantitative comparative study was to examine the possible relationship between nicotine replacement therapy (NRT) and cardiac disorder risk by comparing the rates of cardiac disorder risk of NRT with cardiac disorder risk of non-replacement drugs among smokers seeking smoking cessation. METHODS: The study used retrospective quantitative design, which involved the collection of secondary data from the adverse event reporting system (FAERS) database of the U.S Food and Drug Administration (FDA). Rates of cardiac disorder were compared between the NRT group and non- NRT (varenicline and bupropion) group. Statistical analyses involved using a 2x2 contingency table and logistic regression to calculate odds ratio (reporting odds ratio (ROR)). RESULTS AND DISCUSSION: Unadjusted ROR was 0.45 (95% confidence interval [CI] 0.28, 0.70). With age and sex as confounding factors, the smokers in the NRT group still had lower odds of having cardiac disorder risk than the non-NRT group (adjusted ROR=0.44, 95% CI 0.28, 0.70). CONCLUSION: Our study findings showed lower cardiac disorder risk with the NRT group compared to the non-NRT (varenicline and bupropion) group. While the study did not aim to undermine either using NRT or non-NRT for smoking cessation therapy to prevent smoking illness, the study results offer informed findings that could potentially improve current smoking cessation management using NRT intervention among smokers and enhance smokers' health outcome. Despite the negative signal detection of cardiac disorder risk with NRT as compared to non-NRT in final findings, we still recommend further research on the causal relationship between NRT and non-NRT and cardiac disorder risk.

Two-year efficacy of varenicline tartrate and counselling for inpatient smoking cessation (STOP study): A randomized controlled clinical trial.

INTRODUCTION: Varenicline tartrate is superior for smoking cessation to other tobacco cessation therapies by 52 weeks, in the outpatient setting. We aimed to evaluate the long-term (104 week) efficacy following a standard course of inpatient-initiated varenicline tartrate plus Quitline-counselling compared to Quitline-counselling alone. METHODS: Adult patients (n = 392, 20-75 years) admitted with a smoking-related illnesses to one of three hospitals, were randomised to receive either 12-weeks of varenicline tartrate (titrated from 0.5mg daily to 1mg twice-daily) plus Quitline-counselling, (n = 196) or Quitline-counselling alone, (n = 196), with continuous abstinence from smoking assessed at 104 weeks. RESULTS: A total of 1959 potential participants were screened for eligibility between August 2008 and December 2011. The proportion of participants who remained continuously abstinent (intention-to-treat) at 104 weeks were significantly greater in the varenicline tartrate plus counselling arm (29.2% n = 56) compared to counselling alone (18.8% n = 36; p = 0.02; odds ratio 1.78; 95%CI 1.10 to 2.86, p = 0.02). Twenty-two deaths occurred during the 104 week study (n = 10 for varenicline tartrate plus counselling and n = 12 for Quitline-counselling alone). All of these participants had known or developed underlying co-morbidities. CONCLUSIONS: This is the first study to examine the efficacy and safety of varenicline tartrate over 104 weeks within any setting. Varenicline tartrate plus Quitline-counselling was found to be an effective opportunistic treatment when initiated for inpatient smokers who had been admitted with tobacco-related disease.

Countering Opioid-induced Respiratory Depression in Male Rats with Nicotinic Acetylcholine Receptor Partial Agonists Varenicline and ABT 594.

BACKGROUND: Opioids can induce significant respiratory depression when administered as analgesics for the treatment of acute, postoperative, and chronic pain. There are currently no pharmacologic means of reversing opioid-induced respiratory depression without interfering with analgesia. Further, there is a growing epidemic of opioid overdose that could benefit from therapeutic advancements. The aim of this study was to test the ability of two partial agonists of α4ß2 nicotinic acetylcholine receptors, varenicline (used clinically for smoking cessation) and ABT 594 (tebanicline, developed as an analgesic), to reduce respiratory depression induced by fentanyl, remifentanil, morphine, and a combination of fentanyl and diazepam. METHODS: Whole body plethysmographic recordings, nociception testing, and righting reflex testing were used to examine ventilation, analgesia, and sedation in adult male Sprague-Dawley rats. RESULTS: Pre-, co-, or postadministration of varenicline or ABT 594 did not alter baseline breathing but markedly reduced opioid-induced respiratory depression. Varenicline had no effect on fentanyl-induced analgesia and ABT 594 potentiated fentanyl-induced analgesia. Specifically, 10-min administration of fentanyl induced a decrease in respiratory rate to 43 ± 32% of control in vehicle group, which was alleviated by preadministration of varenicline (85 ± 14% of control, n = 8, P < 0.001) or ABT 594 (81 ± 36% of control, n = 8, P = 0.001). ABT 594 or varenicline with a low dose of naloxone (1 µg/kg), but not varenicline alone, partially reversed fentanyl-induced lethal apnea, but neither compound provided the very rapid and complete reversal of apnea achieved with high doses of naloxone (0.03 to 1 mg/kg). Administration of varenicline (n = 4, P = 0.034) or ABT 594 (n = 4, P = 0.034) prevented lethal apneas induced by the combination of fentanyl and diazepam. CONCLUSIONS: Activation of α4ß2 nicotinic acetylcholine receptors by varenicline and ABT 594 counters opioid-induced respiratory depression without interfering with analgesia.

Varenicline versus nicotine replacement therapy for long-term smoking cessation: an observational study using the Clinical Practice Research Datalink.

BACKGROUND: Smoking is the leading avoidable cause of illness and premature mortality. The first-line treatments for smoking cessation are nicotine replacement therapy and varenicline. Meta-analyses of experimental studies have shown that participants allocated to the varenicline group were 1.57 times (95% confidence interval 1.29 to 1.91 times) as likely to be abstinent 6 months after treatment as those allocated to the nicotine replacement therapy group. However, there is limited evidence about the effectiveness of varenicline when prescribed in primary care. We investigated the effectiveness and rate of adverse events of these medicines in the general population. OBJECTIVE: To estimate the effect of prescribing varenicline on smoking cessation rates and health outcomes. DATA SOURCES: Clinical Practice Research Datalink. METHODS: We conducted an observational cohort study using electronic medical records from the Clinical Practice Research Datalink. We extracted data on all patients who were prescribed varenicline or nicotine replacement therapy after 1 September 2006 who were aged ≥ 18 years. We investigated the effects of varenicline on smoking cessation, all-cause mortality and cause-specific mortality and hospitalisation for: (1) chronic lung disease, (2) lung cancer, (3) coronary heart disease, (4) pneumonia, (5) cerebrovascular disease, (6) diabetes, and (7) external causes; primary care diagnosis of myocardial infarction, chronic obstructive pulmonary disease, depression, or prescription for anxiety; weight in kg; general practitioner and hospital attendance. Our primary outcome was smoking cessation 2 years after the first prescription. We investigated the baseline differences between patients prescribed varenicline and patients prescribed nicotine replacement therapy. We report results using multivariable-adjusted, propensity score and instrumental variable regression. Finally, we developed methods to assess the relative bias of the different statistical methods we used. RESULTS: People prescribed varenicline were healthier at baseline than those prescribed nicotine replacement therapy in almost all characteristics, which highlighted the potential for residual confounding. Our instrumental variable analysis results found little evidence that patients prescribed varenicline had lower mortality 2 years after their first prescription (risk difference 0.67, 95% confidence interval -0.11 to 1.46) than those prescribed nicotine replacement therapy. They had similar rates of all-cause hospitalisation, incident primary care diagnoses of myocardial infarction and chronic obstructive pulmonary disease. People prescribed varenicline subsequently attended primary care less frequently. Patients prescribed varenicline were more likely (odds ratio 1.46, 95% confidence interval 1.42 to 1.50) to be abstinent 6 months after treatment than those prescribed nicotine replacement therapy when estimated using multivariable-adjusted for baseline covariates. Patients from more deprived areas were less likely to be prescribed varenicline. However, varenicline had similar effectiveness for these groups. CONCLUSION: Patients prescribed varenicline in primary care were more likely to quit smoking than those prescribed nicotine replacement therapy, but there was little evidence that they had lower rates of mortality or morbidity in the 4 years following the first prescription. There was little evidence of heterogeneity in effectiveness across the population. FUTURE WORK: Future research should investigate the decline in prescribing of smoking cessation products; develop an optimal treatment algorithm for smoking cessation; use methods for using instruments with survival outcomes; and develop methods for comparing multivariable-adjusted and instrumental variable estimates. LIMITATIONS: Not all of our code lists were validated, body mass index and Index of Multiple Deprivation had missing values, our results may suffer from residual confounding, and we had no information on treatment adherence. TRIAL REGISTRATION: This trial is registered as NCT02681848. 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. 24, No. 9. See the NIHR Journals Library website for further project information.

Smoking is the number one avoidable cause of ill health and death. Experiments suggest that more smokers will quit after being given the drug varenicline than with any other smoking cessation treatment. However, most of the experiments used to license varenicline had a relatively short follow-up (< 1 year) and did not necessarily recruit participants who were representative of smokers seen in a general practice in the UK, who tend to be older, are sicker and more likely to have neuropsychiatric illnesses. In this study, we investigated the outcomes of 287,079 patients prescribed varenicline or nicotine replacement therapy (e.g. nicotine patches and gum). We followed each patient for up to 4 years after they received their prescriptions and matched their data to information on deaths from the Office for National Statistics and hospital admissions. We investigated how often these patients subsequently attended their general practitioner, and how often they received a diagnosis of myocardial infarction, chronic obstructive pulmonary disease, depression or anxiety in primary care. We found that patients who were prescribed varenicline were much more likely to quit smoking up to 4 years after they received treatment and subsequently attended their general practitioner less frequently. These findings were robust across the three different analysis methods we used. We also found that patients prescribed varenicline were much less likely to be ill or to die than those prescribed nicotine replacement therapy. However, these results may be because the patients who were prescribed varenicline were much healthier before they received the prescription. Therefore, these differences in health are unlikely to be caused by taking varenicline or quitting smoking. In conclusion, varenicline helped patients quit smoking, but there was little causal evidence that prescribing patients varenicline causally reduced rates of mortality or morbidity compared with prescribing nicotine replacement therapy.

Nicotine dependence (trait) and acute nicotinic stimulation (state) modulate attention but not inhibitory control: converging fMRI evidence from Go-Nogo and Flanker tasks.

Cognitive deficits during nicotine withdrawal may contribute to smoking relapse. However, interacting effects of chronic nicotine dependence and acute nicotine withdrawal on cognitive control are poorly understood. Here we examine the effects of nicotine dependence (trait; smokers (n = 24) vs. non-smoking controls; n = 20) and acute nicotinic stimulation (state; administration of nicotine and varenicline, two FDA-approved smoking cessation aids, during abstinence), on two well-established tests of inhibitory control, the Go-Nogo task and the Flanker task, during fMRI scanning. We compared performance and neural responses between these four pharmacological manipulations in a double-blind, placebo-controlled crossover design. As expected, performance in both tasks was modulated by nicotine dependence, abstinence, and pharmacological manipulation. However, effects were driven entirely by conditions that required less inhibitory control. When demand for inhibitory control was high, abstinent smokers showed no deficits. By contrast, acutely abstinent smokers showed performance deficits in easier conditions and missed more trials. Go-Nogo fMRI results showed decreased inhibition-related neural activity in right anterior insula and right putamen in smokers and decreased dorsal anterior cingulate cortex activity on nicotine across groups. No effects were found on inhibition-related activity during the Flanker task or on error-related activity in either task. Given robust nicotinic effects on physiology and behavioral deficits in attention, we are confident that pharmacological manipulations were effective. Thus findings fit a recent proposal that abstinent smokers show decreased ability to divert cognitive resources at low or intermediate cognitive demand, while performance at high cognitive demand remains relatively unaffected, suggesting a primary attentional deficit during acute abstinence.

Promoting activity of (α4)3(ß2)2 nicotinic cholinergic receptors reduces ethanol consumption.

There is increasing interest in developing drugs that act at α4ß2 nicotinic acetylcholine receptors (nAChRs) to treat alcohol use disorder. The smoking cessation agent varenicline, a partial agonist of α4ß2 nAChRs, reduces alcohol intake, but its use can be limited by side effects at high therapeutic doses. There are two stoichiometric forms of α4ß2 nAChRs, (α4)3(ß2)2 and (α4)2(ß2)3. Here we investigated the hypothesis that NS9283, a positive allosteric modulator selective for the (α4)3(ß2)2 form, reduces ethanol consumption. NS9283 increased the potency of varenicline to activate and desensitize (α4)3(ß2)2 nAChRs in vitro without affecting other known targets of varenicline. In male and female C57BL/6J mice, NS9283 (10 mg/kg) reduced ethanol intake in a two-bottle choice, intermittent drinking procedure without affecting saccharin intake, ethanol-induced incoordination or ethanol-induced loss of the righting reflex. Subthreshold doses of NS9283 (2.5 mg/kg) plus varenicline (0.1 mg/kg) synergistically reduced ethanol intake in both sexes. Finally, despite having no aversive valence of its own, NS9283 enhanced ethanol-conditioned place aversion. We conclude that compounds targeting the (α4)3(ß2)2 subtype of nAChRs can reduce alcohol consumption, and when administered in combination with varenicline, may allow use of lower varenicline doses to decrease varenicline side effects.

Exercise for Smoking Cessation in Postmenopausal Women: A Randomized, Controlled Trial.

BACKGROUND: Postmenopausal smokers have difficulty quitting smoking and experience considerable weight gain with smoking cessation. We examined whether adjunctive smoking treatment with exercise, compared to a relaxation control condition, could improve cigarette abstinence, decrease cigarettes smoked per day (CPD), and ameliorate changes in body mass index (BMI) in postmenopausal smokers. METHODS: Women (N = 301) signed informed consent and were randomized to treatment at two sites (Universities of Connecticut and Minnesota). We randomized groups of participants to a comprehensive group treatment program that included 12 weeks of varenicline and either a moderate exercise or relaxation component for 6 months. Participants were followed for a year after medication treatment. RESULTS: Overall, 17.3% of patients reported carbon monoxide-verified continuous abstinence for the 9- to 12-week period, and 11.6% reported prolonged abstinence at 1 year, with no significant differences between treatment conditions. CPD reported at study visits showed significant main effects for time in weeks, for site, and for treatment. The Exercise condition reported smoking fewer CPD over time, and that advantage widened over time. In terms of BMI, significant effects for time in weeks, and for the interaction of Week × Treatment condition, reflected gradually increasing BMI in these women over time, but with the increase in BMI slower in the Exercise condition. CONCLUSIONS: Exercise, compared to relaxation, was associated with a reduced BMI and CPD in postmenopausal women, but did not increase end of treatment or prolonged abstinence. Further research is needed to devise exercise programs that increase smoking cessation rates in postmenopausal women. IMPLICATIONS: This study adds to the literature on the effectiveness of a moderate exercise intervention compared to a relaxation control condition as an adjunctive treatment for smoking cessation in postmenopausal women. Our exercise program did not increase end of treatment or prolonged abstinence rates in postmenopausal women; however, there was a beneficial effect on smoking reduction and reduced body mass index. Additional research is needed to devise exercise programs that increase smoking cessation rates in postmenopausal women.

Real-World Effectiveness of Pharmaceutical Smoking Cessation Aids: Time-Varying Effects.

BACKGROUND: There are a limited number of studies that have examined the real-world effectiveness of smoking cessation aids and relapse longitudinally in population-representative samples. This study examines the association between use of nicotine gum, patch, bupropion, and varenicline and time to relapse as well as any changes in the association with increased length of abstinence. METHODS: Data of 1821 current adult smokers (18+) making their first serious quit attempt were compiled from 4504 individuals enrolled in the Ontario Tobacco Survey, a representative telephone survey of Ontario adults, which followed smokers every 6 months for up to 3 years. Use of cessation aids at the time of initial report of a quit attempt was analyzed. A flexible parametric survival model was developed to model length of abstinence, controlling for potential confounders. RESULTS: The best fit model found knots at 3, 13, 43, and 212 days abstinent, suggesting different rates of relapse in the periods marked by those days. Use of the patch and varenicline was associated with lower rates of relapse, but no positive effect was found for bupropion or nicotine gum. The effectiveness of the patch reversed in effect after the first month of abstinence. CONCLUSIONS: This study is one of few reports of long-term quitting in a population-representative sample and demonstrates that the effectiveness of some pharmacological cessation aids (the patch and varenicline can be seen in a population sample). Previous failures in real-world studies of the effectiveness of smoking cessation aids may reflect differences in the products individuals use and differences in the timing of self-reported cessation. IMPLICATIONS: While a large number of randomized controlled trials have shown the efficacy of many pharmaceutical smoking cessation aids, evidence of their effectiveness in observational studies in the real world is ambiguous. This study uses a longitudinal cohort of a representative sample of smokers to show that the effectiveness of pharmaceutical cessation aids can be demonstrated in real-world use situations, but effectiveness varies by product type and has time-varying effects.

Prescribing Prevalence, Effectiveness, and Mental Health Safety of Smoking Cessation Medicines in Patients With Mental Disorders.

OBJECTIVE: We conducted a prospective cohort study of the Clinical Practice Research Database to estimate rates of varenicline and nicotine replacement therapy (NRT) prescribing and the relative effects on smoking cessation, and mental health. METHODS: We used multivariable logistic regression, propensity score matched regression, and instrumental variable analysis. Exposure was varenicline or NRT prescription. Mental disorders were bipolar, depression, neurotic disorder, schizophrenia, or prescriptions of antidepressants, antipsychotics, hypnotics/anxiolytics, mood stabilizers. Outcomes were smoking cessation, and incidence of neurotic disorder, depression, prescription of antidepressants, or hypnotics/anxiolytics. Follow-ups were 3, 6, and 9 months, and at 1, 2, and 4 years. RESULTS: In all patients, NRT and varenicline prescribing declined during the study period. Seventy-eight thousand four hundred fifty-seven smokers with mental disorders aged ≥18 years were prescribed NRT (N = 59 340) or varenicline (N = 19 117) from September 1, 2006 to December 31, 2015. Compared with smokers without mental disorders, smokers with mental disorders had 31% (95% CI: 29% to 33%) lower odds of being prescribed varenicline relative to NRT, but had 19% (95% CI: 15% to 24%) greater odds of quitting at 2 years when prescribed varenicline relative to NRT. Overall, varenicline was associated with decreased or similar odds of worse mental health outcomes than NRT in patients both with and without mental disorders, although there was some variation when analyses were stratified by mental disorder subgroup. CONCLUSIONS: Smoking cessation medication prescribing may be declining in primary care. Varenicline was more effective than NRT for smoking cessation in patients with mental disorders and there is not clear consistent evidence that varenicline is adversely associated with poorer mental health outcomes. IMPLICATIONS: Patients with mental disorders were less likely to be prescribed varenicline than NRT. We triangulated results from three analytical techniques. We found that varenicline was more effective than NRT for smoking cessation in patients with mental disorders. Varenicline was generally associated with similar or decreased odds of poorer mental health outcomes (ie, improvements in mental health) when compared with NRT. We report these findings cautiously as our data are observational and are at risk of confounding.

Efficacy and Safety of Varenicline for Adolescent Smoking Cessation: A Randomized Clinical Trial.

Importance: Cigarette smoking is the leading cause of preventable morbidity and mortality in the United States and worldwide, and most tobacco users begin smoking in adolescence. Although advances have yielded efficacious pharmacotherapies to complement smoking cessation counseling in adults, far less progress has been made in addressing tobacco use in adolescence. Objective: To evaluate the efficacy and safety of varenicline tartrate for smoking cessation in adolescents and young adults. Design, Setting, and Participants: This 2-group randomized, placebo-controlled, double-blind intention-to-treat clinical trial enrolled a volunteer sample of treatment-seeking adolescent and young adult cigarette smokers (n = 157) aged 14 to 21 years at an outpatient clinical site in Charleston, South Carolina, from August 15, 2012, to October 20, 2017. Follow-up was completed on January 25, 2018. Data were analyzed from March 19, 2018, to August 11, 2018, with further revisions completed April 10, 2019. Interventions: Participants were randomized in a 1:1 ratio to a 12-week course of varenicline (n = 77) or placebo (n = 80). All participants received weekly smoking cessation counseling. Main Outcomes and Measures: The preselected primary efficacy outcome was urine cotinine level-confirmed 7-day abstinence at the end of treatment. Secondary efficacy outcomes included weekly abstinence throughout active treatment, abstinence at posttreatment follow-up visits, and time to first 7-day abstinence. The primary safety outcome was the frequency of treatment-emergent adverse events. Results: A total of 157 participants were enrolled (94 male [59.9%]; mean [SD] age, 19.1 [1.5] years). The varenicline and placebo groups did not differ in the primary outcome of cotinine-confirmed self-reported 7-day abstinence at the end of treatment (varenicline group, 4 of 45 [8.9%]; placebo group, 4 of 45 [8.9%]; risk ratio [RR], 0.97; 95% CI, 0.29-2.99; P = .96). However, among secondary outcomes, the varenicline group achieved self-reported earlier abstinence of at least 7 days (hazard ratio, 1.91; 95% CI, 1.12-3.27) and demonstrated higher rates of self-reported weekly abstinence during the full course of treatment (RR, 1.81; 95% CI, 1.09-2.99; P = .02) and at posttreatment follow-up (RR, 1.82; 95% CI, 1.01-3.28; P = .02). Study medication was generally well tolerated, and treatment-emergent adverse events did not differ between groups (any adverse events, 55 [71.4%] in the varenicline group vs 60 [75.0%] in the placebo group; RR, 0.95; 95% CI, 0.79-1.15; P = .61). Conclusions and Relevance: When added to weekly cessation counseling for adolescent cigarette smokers, varenicline, compared with placebo, was well tolerated but did not improve end-of-treatment abstinence. However, varenicline may hasten abstinence and yield improvements in posttreatment abstinence outcomes. Trial Registration: ClinicalTrials.gov identifier: NCT01509547.

Nicotine Self-Administration as Paradigm for Medication Discovery for Smoking Cessation: Recent Findings in Medications Targeting the Cholinergic System.

Tobacco kills every year approximately six million people as a direct result of direct use, and it is still considered one of the most excruciating threats for human health worldwide. The low successful rates of the currently available pharmacotherapies to assist in quitting tobacco use suggest there is a need for more effective treatments.The intravenous self-administration (IVSA) paradigm is considered the gold standard to study voluntary drug intake in animal models, including nicotine. The IVSA paradigm has been used to identify key mechanisms involved in the addictive properties of nicotine in both rodents and nonhuman primates. In this chapter we describe how the IVSA paradigm has served to further investigate the role of nicotinic acetylcholine receptors (nAChRs) in the reinforcing properties of nicotine. Notably, this review will cover recent advances (i.e., research carried out during the past decade) using the IVSA paradigm, with a focus on the status of research on current smoking cessation medications (such as varenicline and bupropion) and of other nAChR ligands.The combination of the IVSA paradigm with pharmacological and genetic tools (e.g., knockout animals) has greatly contributed to our understanding of the role of specific subtype nAChRs in nicotine reinforcement processes. We also discuss some of the limitations of the IVSA paradigm so these can be taken into consideration when interpreting and designing new studies.