Extinguishing the rewarding value of smoke cues: pharmacological and behavioral treatments

Effects of mint, menthol, and tobacco-flavored e-cigarettes on tobacco withdrawal symptoms in adults who smoke menthol cigarettes: A laboratory pilot study

BACKGROUND

Menthol cigarette smoking has remained stable or increased in certain groups, despite an overall decline in cigarette smoking rates in the U.S. Understanding whether e-cigarettes alter patterns of menthol cigarette use is critical to informing efforts for reducing the public health burden of menthol cigarette smoking. This 2019-2020 laboratory pilot study evaluated whether self-administration of mint-, menthol-, or tobacco-flavored e-cigarettes would differentially impact tobacco withdrawal symptoms in e-cigarette-naïve adults who smoke menthol cigarettes daily.

METHODS

Participants (N=17; 35.3% Female; mean age=51.8) attended three laboratory sessions after 16-hours of tobacco abstinence. Participants self-administered a study-provided JUUL e-cigarette (0.7mL with 5% nicotine by weight) at each session in which flavor was manipulated (mint vs. menthol vs. tobacco; order randomized). Participants completed pre- and post-e-cigarette administration self-report assessments on smoking urges, nicotine withdrawal, and positive and negative affect states. Multilevel linear regression models tested differences between the three flavor conditions for individual study outcomes.

RESULTS

Following overnight tobacco abstinence, vaping either a mint or menthol (vs. tobacco) flavored e-cigarette led to significantly greater reductions in smoking urges over time; menthol (vs. tobacco) flavored e-cigarettes also suppressed urges to smoke for pleasure. Notably, no differences in nicotine withdrawal, positive affect, or negative affect were observed.

CONCLUSIONS

In this laboratory pilot study, mint and menthol (vs. tobacco) flavored e-cigarettes provided some negative reinforcement effects via acute reductions in smoking urges during tobacco abstinence, yet only menthol flavored e-cigarettes demonstrated suppressive effects on smoking urges for pleasure in adults who smoke menthol cigarettes daily.

Effects of Framing Nicotine Reduction in Cigarettes on Anticipated Tobacco Product Use Intentions and Risk Perceptions Among US Adult Smokers

Introduction

In 2017, the US Food and Drug Administration (FDA) proposed lowering the amount of nicotine in combusted cigarettes to minimally addictive levels. If used, to encourage cessation and maximize the benefits of this action, the FDA needs to determine the most effective way to communicate to the public the practical impact of this nicotine tobacco product standard.

Methods

Data were collected in 2018 from a nationally representative, online probability sample of 1198 adult smokers (aged ≥18 years old) in the United States. Smokers were randomly assigned one of five versions of the question regarding what they would most likely do if nicotine in cigarettes was reduced (nicotine levels were reduced by 95%; the government reduced nicotine levels by 95%; cigarettes were no longer addictive; cigarettes no longer relieved cravings; cigarettes were changed so that you would be able to quit more easily). Effects of framing on anticipated tobacco use intentions and perceived risk of very low nicotine cigarettes (VLNCs) were evaluated with multinomial logistic regressions.

Results

Framing the nicotine tobacco product standard as cigarettes no longer relieved cravings resulted in the highest proportion of smokers reporting they intend to quit in response to this standard (43.9%), lowest proportions reporting anticipated intentions to continue using combusted tobacco products (45.3%), and lowest proportion believing that VLNCs are less harmful than regular cigarettes (26%).

Conclusions

Different frames of nicotine reduction in cigarettes differentially affected smokers’ anticipated tobacco use intentions and perceived risk of VLNCs. Presenting reduction as making cigarettes unable to relieve cravings might be particularly effective at motivating cessation.

Early Subjective Sensory Experiences with "Cigalike" E-cigarettes Among African American Menthol Smokers: A Qualitative Study

Introduction

Despite smoker interest in e-cigarettes as a harm reduction or cessation aid, many smokers prematurely discontinue vaping after trying a product. This study explored the role of early subjective sensory experiences in vaping persistence and desistance.

Methods

African American menthol cigarette smokers aged ≥18 years (N = 15; M = 54.1 years; SD = 8.2), motivated to quit smoking, and interested in trying e-cigarettes were recruited in Washington, DC. Participants were followed for 3 weeks and provided menthol cigalike e-cigarettes after Week 1. Participants completed three interviews about their vaping experiences. Thematic analysis of responses was designed to understand the sensory aspects of vaping.

Results

During the first 2 weeks of vaping, four participants reported a positive vaping experience while 11 reported decreased satisfaction. Salient sensory attributes of dissatisfaction included poor taste, insufficient throat hit, difficulty pulling, and a lack of "whole body" satisfaction compared to their preferred cigarette brand.

Conclusions

The sensory experiences with a specific cigalike e-cigarette were related to vaping persistence and desistence. Although this was a small volunteer sample of African American menthol smokers motivated to quit smoking, 27% (N = 4) of participants with a positive vaping experience continued using the product, while 73% (N = 11) of participants' vaping experience was unsatisfactory across several experiential categories. In future research of e-cigarettes' efficacy as a smoking cessation or reduction aid, both device characteristics and smokers' expectations for these devices should be considered, so vapers do not expect the same taste sensations, throat sensations, and "whole body" satisfaction as they experienced with their menthol cigarettes.

Implications

The subjective sensory experiences associated with initial e-cigarette product use are associated with use patterns. Subjective sensory experiences may also help understand the differences in the appeal, satisfaction, and harm-reduction potential of the rapidly evolving diverse types of products emerging in the marketplace. How products meet the sensory needs of smokers wanting to switch or quit smoking may influence adherence and success rates.

Acute effects of inhaled menthol on the rewarding effects of intravenous nicotine in smokers

OBJECTIVE

This double-blind, placebo controlled study examined whether menthol inhaled from an electronic cigarette (e-cigarette) would change subjective and withdrawal alleviating effects of intravenous nicotine in young adult smokers.

METHODS

A total of 32 menthol-preferring smokers and 25 non-menthol-preferring smokers participated in the study that consisted of a random sequence of three different inhaled menthol conditions (0.0%, 0.5%, and 3.2%) across three test sessions (a single menthol condition per session). In each test session (performed at least 24 hours apart), a random order of saline, and two different nicotine infusions of 0.25 mg and 0.5 mg/70 kg of bodyweight were administered, one hour apart, concurrent with menthol inhalation.

RESULTS

While menthol did not alter the positive subjective effects of nicotine, menthol significantly enhanced aversive effects of nicotine in non-menthol-preferring smokers and reduced smoking urges in menthol-preferring smokers. In addition, menthol-preferring smokers reported blunted positive subjective responses to nicotine and less severe nicotine withdrawal after overnight nicotine deprivation. Finally, compared to non-menthol-preferring smokers, menthol-preferring smokers had a significantly lower baseline nicotine metabolite ratio indicating slower nicotine metabolism within our sample of menthol-preferring smokers.

CONCLUSIONS

Our findings did not support an enhancement of nicotine's positive subjective effects from inhaled menthol. However, as compared to non-menthol-preferring smokers, menthol-preferring smokers had blunted positive subjective responses to nicotine and reduced overnight withdrawal severity that may be partly due to inhibition of nicotine metabolism from chronic exposure to inhaled menthol. Collectively, these results reveal a more complex and nuanced role of inhaled menthol in smokers than previously recognized.

Cigarette Design Features: Effects on Emission Levels, User Perception, and Behavior

Objectives

This paper describes the effects of non-tobacco, physical cigarette design features on smoke emissions, product appeal, and smoking behaviors - 3 factors that determine smoker's exposure and related health risks.

Methods

We reviewed available evidence for the impact of filter ventilation, new filter types, and cigarettes dimensions on toxic emissions, smoker's perceptions, and behavior. For evidence sources we used scientific literature and websites providing product characteristics and marketing information.

Results

Whereas filter ventilation results in lower machine-generated emissions, it also leads to perceptions of lighter taste and relative safety in smokers who can unwittingly employ more intense smoking behavior to obtain the desired amount of nicotine and sensory appeal. Filter additives that modify smoke emissions can also modify sensory cues, resulting in changes in smoking behavior. Flavor capsules increase the cigarette's appeal and novelty, and lead to misperceptions of reduced harm. Slim cigarettes have lower yields of some smoke emissions, but smoking behavior can be more intense than with standard cigarettes.

Conclusions

Physical design features significantly impact machine-measured emission yields in cigarette smoke, product appeal, smoking behaviors, and exposures in smokers. The influence of current and emerging design features is important in understanding the effectiveness of regulatory actions to reduce smoking-related harm.

Effectiveness of continuing nicotine replacement after a lapse: A randomized trial

INTRODUCTION

Four post-hoc analyses of prior trials found smokers using nicotine patch following a lapse were less likely to progress to relapse compared to those using a placebo patch following a lapse. We attempted a conceptual replication test of these results via a randomized trial of instructions to continue vs. stop nicotine patch after a lapse.

METHODS

Smokers trying to quit (n=701) received nicotine patch (21/14/7mg) and brief phone counseling (six 15-min sessions). We randomized smokers to receive instructions for and rationale for stopping vs. continuing patch after a lapse. The messages were repeated before and after cessation and following lapses via counseling, phone and written instructions.

RESULTS

Among those who lapsed, those told to Continue Patch did not have a greater incidence of 7-day abstinence at 4months (primary outcome) than those told to Discontinue Patch (51% vs. 46%). Most (81%) participants in the Discontinue condition stopped patch for only 1-2days and then resumed abstinence and patch use. Analyses based on all participants randomized were similar. Adverse events were as expected and did not differ between conditions.

CONCLUSION

Instructions to continue nicotine patch after a lapse did not increase return to abstinence. These negative results may have occurred because actual use of patch after a lapse was similar in the two conditions. Also, allowing patch use while smoking may have reduced motivation to stay abstinent.

Preliminary validity of the modified Cigarette Evaluation Questionnaire in predicting the reinforcing effects of cigarettes that vary in nicotine content

Validity studies evaluating self-report measures in relation to behavioral preference of cigarettes varying in nicotine content are needed. The current study examined the relationship between ratings on the modified Cigarette Evaluation Questionnaire (mCEQ) and the relative reinforcing effects of Spectrum research cigarettes (15.8, 5.2, 2.4, 0.4 mg per gram of tobacco). Data for this secondary analysis were obtained from a double-blind study (Higgins et al., 2017) evaluating the subjective and reinforcing effects of Spectrum cigarettes under acute smoking abstinence. Current smokers (N = 26) were recruited from three vulnerable smoking populations (economically disadvantaged women of reproductive age, opioid-maintained individuals, individuals with affective disorders). In Phase 1 (five sessions), the mCEQ (Satisfaction, Psychological Reward, Enjoyment of Respiratory Tract Sensations, Craving Reduction, Aversion subscales) was administered following ad lib smoking of Spectrum cigarettes and subscale differences scores were calculated by subtracting ratings of the 15.8 mg/g cigarette from ratings of the reduced nicotine content cigarettes. In Phase 2 (six sessions), participants completed six 2-dose concurrent choice tests. The relationship between mCEQ subscale difference scores from Phase 1 and nicotine dose choice from Phase 2 was examined using mixed-model repeated-measures analyses of variance. Higher Satisfaction and lower Aversion subscale difference scores were associated with choosing the 15.8 mg/g cigarette more than the 5.2, 2.4, and 0.4 mg/g cigarettes. Scores on the other mCEQ subscales were not associated with nicotine choice. These results provide support for validity of the mCEQ Satisfaction and Aversion subscales predicting the relative reinforcing effects and abuse liability of varying nicotine content cigarettes. (PsycINFO Database Record

Recent developments in the behavioural and pharmacological enhancement of extinction of drug seeking

One of the principal barriers to overcoming addiction is the propensity to relapse, even after months or years of abstinence. Relapse can be precipitated by cues and contexts associated with drug use; thus, decreasing the conditioned properties of these cues and contexts may assist in preventing relapse. The predictive power of drug cues and contexts can be reduced by repeatedly presenting them in the absence of the drug reinforcer, a process known as extinction. The potential of extinction to limit relapse has generated considerable interest and research over the past few decades. While pre-clinical animal models suggest extinction learning assists relapse prevention, treatment efficacy is often lacking when extinction learning principles are translated into clinical trials. Conklin and Tiffany (Addiction, 2002) suggest the lack of efficacy in clinical practice may be due to limited translation of procedures demonstrated through animal research and propose several methodological improvements to enhance extinction learning for drug addiction. This review will examine recent advances in the behavioural and pharmacological manipulation of extinction learning, based on research from pre-clinical models. In addition, the translation of pre-clinical findings-both those suggested by Conklin and Tiffany () and novel demonstrations from the past 13 years-into clinical trials and the efficacy of these methods in reducing craving and relapse, where available, will be discussed. Finally, we highlight areas where promising pre-clinical models have not yet been integrated into current clinical practice but, if applied, could improve upon existing behavioural and pharmacological methods.

Menthol tobacco use is correlated with mental health symptoms in a national sample of young adults: implications for future health risks and policy recommendations

Background

Depression and anxiety are correlated with greater nicotine dependence, smoking persistence, and relapse back to smoking after a quit attempt. Menthol cigarette smoking, which is prevalent in young adults, is associated with nicotine dependence, progression to regular smoking, and worse cessation outcomes than non-menthol smoking. Few have established a link between menthol tobacco use, beyond just smoking, with mental health in this high-risk age group. This study examined the association of menthol tobacco use to anxiety and depression in a national sample of young adults.

Methods

Data were from Waves 1 through 7 (n = 9720, weighted) of the Truth Initiative Young Adult Cohort, a national sample of men and women aged 18 to 34 assessed every 6-months. Demographics, past 30-day use of non-menthol and menthol tobacco products, and current alcohol, marijuana, and other drug use were assessed among those with depression and anxiety.

Results

Thirty nine percent of current tobacco users used menthol as their preferred brand. Using a cross-sectional analysis (collapsed across waves), past 30-day menthol tobacco was uniquely associated with greater odds of both depression and anxiety, beyond the effects of demographic and substance correlates and non-menthol tobacco product use.

Conclusions

Menthol is disproportionately used among young adults tobacco users with mental health problems, above and beyond the impact of a variety of other mental health and tobacco use risk factors. Findings suggest a strong link between menthol tobacco use and poor health outcomes. Policies should be developed to deter menthol tobacco use in vulnerable groups.

Acoustic startle and prepulse inhibition predict smoking lapse in posttraumatic stress disorder

Most smokers who attempt to quit lapse within the first week and are ultimately unsuccessful in their quit attempt. Nicotine withdrawal exacerbates cognitive and attentional problems and may be one factor in smoking relapse. The startle reflex response and prepulse inhibition (PPI) of the response are sensitive to arousal and early attentional dysregulation. The current study examined whether startle response and PPI are related to early smoking lapse, and if this differs in people with and without posttraumatic stress disorder (PTSD). Participants with (N = 34) and without (N = 57) PTSD completed a startle reflex and PPI assessment during (1) ad lib smoking (2) on the first day of abstinence during a quit attempt. Most (88%) participants lapsed within the first week of the quit attempt. PTSD status predicted shorter time to lapse. Larger startle magnitude and greater PPI predicted a longer duration before smoking lapse. When diagnostic groups were examined separately, greater PPI predicted a longer successful quit attempt only in participants with a PTSD diagnosis. The startle reflex response and PPI may provide an objective, neurophysiological evaluation of regulation of arousal and early attentional processes by nicotine, which are important factors in smoking cessation success.

Withdrawal: Expanding a Key Addiction Construct

Withdrawal is an essential component of classical addiction theory; it is a vital manifestation of dependence and motivates relapse. However, the traditional conceptualization of withdrawal as a cohesive collection of symptoms that emerge during drug deprivation and decline with either the passage of time or reinstatement of drug use, may be inadequate to explain scientific findings or fit with modern theories of addiction. This article expands the current understanding of tobacco withdrawal by examining: (1) withdrawal variability; (2) underlying causes of withdrawal variability, including biological and person factors, environmental influences, and the influence of highly routinized behavioral patterns; (3) new withdrawal symptoms that allow for enhanced characterization of the withdrawal experience; and (4) withdrawal-related cognitive processes. These topics provide guidance regarding the optimal assessment of withdrawal and illustrate the potential impact modern withdrawal conceptualization and assessment could have on identifying treatment targets.

Menthol facilitates the intravenous self-administration of nicotine in rats

Menthol is preferred by ~25% of smokers and is the most common flavoring additive in tobacco and electronic cigarettes. Although some clinical studies have suggested that menthol facilitates the initiation of smoking and enhances the dependence on nicotine, many controversies remain. Using licking as the operant behavior, we found that adolescent rats self-administering nicotine (30μg/kg/infusion, free base, i.v.) with contingent oral menthol (60μl, 0.01% w/v) obtained significantly more infusions than rats receiving a vehicle cue or rats self-administering i.v. saline with a menthol cue. Rats yoked to their menthol-nicotine masters emitted significantly fewer licks on the active spouts, indicating that contingent pairing between nicotine and menthol is required for sustained nicotine intake. Rats that self-administered nicotine with a menthol cue also exhibited a long-lasting extinction burst and robust reinstatement behavior, neither of which were observed in rats that self-administered saline with a menthol cue. The cooling sensation of menthol is induced by activating the transient receptor potential M8 (TRPM8) channel. When WS-23, an odorless agonist of the TRPM8 channel, was used as a contingent cue for nicotine, the rats obtained a similar number of nicotine infusions as the rats that were provided a menthol cue and exhibited a strong preference for the active spout. In contrast, highly appetitive taste and odor cues failed to support nicotine self-administration. These data indicated that menthol, likely by inducing a cooling sensation, becomes a potent conditioned reinforcer when it is contingently delivered with nicotine. Together, these results provide a key behavioral mechanism by which menthol promotes the use of tobacco products or electronic cigarettes.

Nicotine and non-nicotine smoking factors differentially modulate craving, withdrawal and cerebral blood flow as measured with arterial spin labeling

Smoking cessation results in withdrawal symptoms such as craving and negative mood that may contribute to lapse and relapse. Little is known regarding whether these symptoms are associated with the nicotine or non-nicotine components of cigarette smoke. Using arterial spin labeling, we measured resting-state cerebral blood flow (CBF) in 29 adult smokers across four conditions: (1) nicotine patch+denicotinized cigarette smoking, (2) nicotine patch+abstinence from smoking, (3) placebo patch+denicotinized cigarette smoking, and (4) placebo patch+abstinence from smoking. We found that changes in self-reported craving positively correlated with changes in CBF from the denicotinized cigarette smoking conditions to the abstinent conditions. These correlations were found in several regions throughout the brain. Self-reported craving also increased from the nicotine to the placebo conditions, but had a minimal relationship with changes in CBF. The results of this study suggest that the non-nicotine components of cigarette smoke significantly impact withdrawal symptoms and associated brain areas, independently of the effects of nicotine. As such, the effects of non-nicotine factors are important to consider in the design and development of smoking cessation interventions and tobacco regulation.

Reduced nicotine cigarettes: smoking behavior and biomarkers of exposure among smokers not intending to quit

BACKGROUND

The U.S. FDA has the authority to limit the nicotine content of cigarettes; however, there are concerns that reduced nicotine cigarettes will be smoked more intensely and, therefore, will increase exposure to toxic chemicals in smoke. This study examined changes in consumer behavior and exposure in response to cigarettes with substantially reduced nicotine content.

METHODS

Seventy-two adult smokers completed an unblinded trial of reduced nicotine cigarettes. Participants completed a 7-day baseline period during which they smoked their usual cigarette brand, followed by consecutive 7-day periods smoking cigarettes with progressively lower nicotine levels (0.6, 0.3, and 0.05 mg emission Quest cigarettes). Nicotine dependence and withdrawal, smoking behavior, and biomarkers of exposure were assessed for each 7-day period.

RESULTS

Significant reductions in nicotine intake were observed between usual brand smoking (∼1.2 mg nicotine) and the 0.3 and 0.05 mg nicotine emission cigarettes, but not the 0.6 mg cigarette. The findings provide little evidence of compensatory smoking of Quest cigarettes, with no increases in exhaled breath carbon monoxide levels, smoking intensity, or levels of 1-hydroxypyrene across study periods. No significant differences were observed for smoking urges or measures of nicotine dependence.

CONCLUSIONS

The study adds to the evidence that cigarettes with markedly reduced nicotine content are not associated with increased smoking intensity or exposure to smoke toxicants.

IMPACT

The findings add to the evidence base on reduced nicotine content cigarettes and have the potential to inform FDA policy on nicotine levels.

Agonist replacement for stimulant dependence: a review of clinical research

Stimulant use disorders are an unrelenting public health concern worldwide. Agonist replacement therapy is among the most effective strategies for managing substance use disorders including nicotine and opioid dependence. The present paper reviewed clinical data from human laboratory self-administration studies and clinical trials to determine whether agonist replacement therapy is a viable strategy for managing cocaine and/or amphetamine use disorders. The extant literature suggests that agonist replacement therapy may be effective for managing stimulant use disorders, however, the clinical selection of an agonist replacement medication likely needs to be based on the pharmacological mechanism of the medication and the stimulant abused by patients. Specifically, dopamine releasers appear most effective for reducing cocaine use whereas dopamine reuptake inhibitors appear most effective for reducing amphetamine use.

An exploratory examination of the mechanisms through which pre-quit patch use aids smoking cessation

RATIONALE AND OBJECTIVES

Patches are traditionally started on the day a quit attempt begins. Recently, a number of studies have established that the patch's effectiveness is improved by starting the treatment before quitting [pre-quit patch (PQP) use]. In an exploratory study, we investigate a proposed mechanism through which PQP use might promote abstinence: that PQP reduces satisfaction with smoking (either directly or via craving), which in turn leads to reduction and that smoking reduction promotes abstinence.

METHODS

Fifty-seven interested quitters used handheld computers to monitor their smoking satisfaction, withdrawal and smoking in real time for 17 days, leading up to a quit attempt. All participants received 21 mg/24 h patches for 2 weeks before and for up to 10 weeks after quitting. Carbon dioxide (CO)-verified 28-day abstinence was assessed.

RESULTS

During PQP treatment, participants reported significant reductions in both the satisfaction gained from smoking (p < 0.001) and their daily cigarette consumption (p < 0.001). Craving did not decrease; however, there was an interaction between time and nicotine dependence; craving decreased only among low dependent participants. Multilevel structural equation modelling revealed a direct effect of satisfaction on smoking rate. Craving did not mediate this relationship. Smoking reduction during the PQP treatment phase was not significantly associated with abstinence.

CONCLUSIONS

The real-time data collection protocol utilised allowed for a fine-grained examination of smoking during PQP treatment. The results suggest that the reduction in daily cigarette smoking typically observed during PQP treatment is due to reductions in satisfaction with smoking. Unlike previous studies, however, smoking reduction was not significantly related to later abstinence, even though the odds ratio was comparably. Potential clinical implications of these findings are discussed.

Repeated nicotine exposure during adolescence alters reward-related learning in male and female rats

RATIONALE

Repeated nicotine exposure causes neuroadaptations in limbic cortico-striatal circuits involved in learning and motivation. Such alterations are relevant to addiction because they are suggested to mediate the ability of smoking-associated stimuli to control behavior and to enhance nicotine-seeking and -taking behaviors. Female smokers report higher cue reactivity relative to their male counter parts, yet little is known about putative gender-specific effects of adolescent nicotine exposure on reward-related learning. Prior repeated nicotine exposure in adult male rats enhances Pavlovian approach behavior and conditioned reinforcement.

OBJECTIVE

Given that smoking is typically initiated during adolescence, here we assessed the extent to which adolescent nicotine exposure impacts Pavlovian approach and conditioned reinforcement in male and female rats.

METHODS

Rats were injected with nicotine on postnatal days 31-45 prior to training on Pavlovian approach behavior starting on day 51. They were trained to associate a conditioned stimulus (CS), illumination of a magazine light, and tone, with an unconditioned stimulus (US), the delivery of water, for 10-daily sessions, and then were tested on the acquisition of responding with conditioned reinforcement.

RESULTS

Adolescent nicotine exposure selectively increased approach to the magazine during the CS in males but decreased approach to the magazine during the CS in female rats. Vehicle-exposed female rats, however, showed greater magazine approach during the CS than did male control rats. Prior nicotine exposure also enhanced conditioned reinforcement in both male and female rats.

CONCLUSIONS

Repeated exposure to nicotine during adolescence had opposite effects on Pavlovian approach behavior in male and female rats but enhanced acquisition of a new response with conditioned reinforcement. Novel information on how nicotine exposure influences reward-related learning during adolescence may increase our understanding of neurobiological mechanisms involved in the initiation of smoking behavior.

Effects of smoking on the acoustic startle response and prepulse inhibition in smokers with and without posttraumatic stress disorder

RATIONALE

Cigarette smokers smoke in part because nicotine helps regulate attention. Prepulse inhibition (PPI) of the startle reflex is a measure of early attentional gating that is reduced in abstinent smokers and in groups with attention regulation difficulties. Attention difficulties are found in people with posttraumatic stress disorder (PTSD).

OBJECTIVES

The aim of this study is to assess whether smoking and abstinence differentially affect the startle response and PPI in smokers with and without PTSD.

METHODS

Startle response and PPI (prepulses at 60, 120, or 240 ms) were measured in smokers with (N = 39) and without (N = 61) PTSD, while smoking and again while abstinent.

RESULTS

Participants with PTSD produced both larger magnitude and faster latency startle responses than controls. Across groups, PPI was greater when smoking than when abstinent. The PTSD and control group exhibited different patterns of PPI across prepulse intervals when smoking and when abstinent. Older age was associated with reduced PPI, but only when abstinent from smoking.

CONCLUSIONS

The effects of PTSD on startle magnitude and of smoking on PPI replicate earlier studies. The different pattern of PPI exhibited in PTSD and control groups across prepulse intervals, while smoking and abstinent suggests that previous research on smoking and PPI has been limited by not including longer prepulse intervals, and that nicotine may affect the time course as well as increasing the level of PPI. The reduced PPI among older participants during abstinence suggests that nicotine may play a role in maintaining attention in older smokers, which may motivate continued smoking in older individuals.

Escalating doses of transdermal nicotine in heavy smokers: effects on smoking behavior and craving

Fixed-dose nicotine replacement therapy (NRT) is efficacious for smoking cessation in the general population of smokers. However, it is less effective in populations with psychiatric comorbidities and/or severe tobacco dependence where the percent nicotine replacement is suboptimal. The objective of this pilot study was to determine the effectiveness of nicotine patch dose titration in response to continued smoking in heavily dependent smokers with psychiatric comorbidity. In a single-arm, open-label study adult smokers (mean cigarettes per day, 25.4 ± 13.4; range, 14-43; n = 12) willing to quit were treated with escalating doses of transdermal nicotine and brief counseling intervention if they continued to smoke over a 9-week treatment period. Plasma nicotine and cotinine, along with expired carbon monoxide levels, and the subjective effects of smoking, urge to smoke, demand elasticity, and mood symptoms were also assessed. The mean NRT dose was 32.7 (SD, 16.4) mg/d (range, 7-56 mg/d). Smokers reported significant reductions in both cigarettes per day (mean decrease, 18.4 ± 11.5) confirmed by expired carbon monoxide (mean decrease, 13.5 ± 13.0) with no significant changes in plasma nicotine concentrations during the course of NRT dose titration. There were significant effects on the subjective effects of smoking and measures of smoking behavior. Most commonly reported adverse events were respiratory infections, skin irritation at patch site, nausea, and sleep disturbances, which were generally mild and transient. Titrating doses of NRT to effect with brief intervention hold promise as an effective clinical strategy to assist heavily dependent psychiatrically ill smokers to change their smoking behavior.

Not so Cool? Menthol's discovered actions on the nicotinic receptor and its implications for nicotine addiction

Nicotine cigarette smoke is a large public health burden worldwide, contributing to various types of disease. Anti-tobacco media campaigns and control programs have significantly reduced smoking in the United States, yet trends for menthol cigarette smoking have not been as promising. Menthol cigarette smoking is particularly prevalent among young adults and African Americans, with implications for long-term impacts on health care. Continuing high rates of menthol cigarette addiction call into question the role of menthol in nicotine addiction. To date, a biological basis for the high rate of addiction and relapse among menthol cigarette smokers has not been defined. Studies have demonstrated a role for menthol in the metabolism of nicotine in the body. More recent findings now reveal an interaction between menthol and the nicotinic acetylcholine (nACh) receptor in cells. This receptor is central to the actions of nicotine in the brain, and plays an important role in nicotine addiction. The newly discovered effect of menthol on nACh receptors may begin to explain the unique addictive properties of menthol cigarettes.

Potential therapeutic uses of mecamylamine and its stereoisomers

Mecamylamine (3-methylaminoisocamphane hydrochloride) is a nicotinic parasympathetic ganglionic blocker, originally utilized as a therapeutic agent to treat hypertension. Mecamylamine administration produces several deleterious side effects at therapeutically relevant doses. As such, mecamylamine's use as an antihypertensive agent was phased out, except in severe hypertension. Mecamylamine easily traverses the blood-brain barrier to reach the central nervous system (CNS), where it acts as a nicotinic acetylcholine receptor (nAChR) antagonist, inhibiting all known nAChR subtypes. Since nAChRs play a major role in numerous physiological and pathological processes, it is not surprising that mecamylamine has been evaluated for its potential therapeutic effects in a wide variety of CNS disorders, including addiction. Importantly, mecamylamine produces its therapeutic effects on the CNS at doses 3-fold lower than those used to treat hypertension, which diminishes the probability of peripheral side effects. This review focuses on the pharmacological properties of mecamylamine, the differential effects of its stereoisomers, S(+)- and R(-)-mecamylamine, and the potential for effectiveness in treating CNS disorders, including nicotine and alcohol addiction, mood disorders, cognitive impairment and attention deficit hyperactivity disorder.

A randomized controlled trial of a smoking cessation intervention conducted among prisoners

AIM

To evaluate the efficacy of nortriptyline (NOR) added to a multi-component smoking cessation intervention, which included cognitive-behavioural therapy (CBT) and provision of nicotine replacement therapy (NRT).

DESIGN

Randomized controlled trial (RCT) comparing two study groups with blinded follow-up at 3, 6 and 12 months. Both groups received a multi-component smoking cessation intervention comprising two half-hour individual sessions of CBT and NRT with either active NOR or placebo.

SETTING

Prisons in New South Wales (17) and Queensland (one), Australia.

PARTICIPANTS

A total of 425 male prisoners met inclusion criteria and were allocated to either treatment (n = 206) or control group (n = 219).

MEASUREMENTS

Primary end-points at 3, 6 and 12 months were continuous abstinence, point prevalence abstinence and reporting a 50% reduction in smoking. Smoking status was confirmed by expired carbon monoxide, using a cut-point of ≤10 parts per million.

FINDINGS

Participants' demographics and baseline tobacco use were similar in treatment and control groups. Based on an intention-to-treat analysis, continuous abstinence between the treatment and control groups was not significantly different at 3 months (23.8 versus 16.4%), 6 months (17.5 versus 12.3%) and 12 months (11.7 versus 11.9%).

CONCLUSION

Adding nortriptyline to a smoking cessation treatment package consisting of behavioural support and nicotine replacement therapy does not appear to improve long-term abstinence rates in male prisoners.

Randomized trial of the effectiveness of combined behavioral/pharmacological smoking cessation treatment in Syrian primary care clinics

AIMS

Effectiveness of nicotine replacement therapy (NRT) for smoking cessation has not been evaluated in low income countries, such as Syria, where it is expensive and not widely available. We evaluated whether nicotine patch boosts smoking cessation rates when used in conjunction with behavioral support in primary care clinics in Aleppo, Syria.

DESIGN

Two arm, parallel group, randomized, placebo controlled, double-blinded multi-site trial.

SETTING

Four primary care clinics in Aleppo, Syria.

PARTICIPANTS

 Two hundred and sixty-nine adult primary care patients received behavioral cessation counseling from a trained primary care physician and were randomized to receive six weeks of treatment with nicotine versus placebo patch.

MEASUREMENTS

Primary end-points were prolonged abstinence (no smoking after a 2-week grace period) at end of treatment, and 6 and 12 months post-quit day, assessed by self-report and exhaled carbon monoxide levels of <10 p.p.m.

FINDINGS

Treatment adherence was excellent and nicotine patch produced expected reductions in urges to smoke and withdrawal symptoms, but no treatment effect was observed. The proportion of patients in the nicotine and placebo groups with prolonged abstinence was 21.6% and 20.0%, respectively, at end of treatment, 13.4% and 14.1% at 6 months, and 12.7% and 11.9% at 12 months.

CONCLUSIONS

 Nicotine patches may not be effective in helping smokers in low-income countries to stop when given as an adjunct to behavioural support.

Predictors of lapse in first week of smoking abstinence in PTSD and non-PTSD smokers

INTRODUCTION

Retrospective research suggests smokers with posttraumatic stress disorder (PTSD) lapse more quickly after their quit date. Ecological momentary assessment (EMA) research is needed to confirm the presence of early smoking lapse in PTSD and form conceptualizations that inform intervention.

METHODS

Smokers with (n = 55) and without (n = 52) PTSD completed alarm-prompted EMA of situational and psychiatric variables the week before and after a quit date, and self-initiated EMA following smoking lapses. Blood samples at baseline and on the quit date allowed assessment of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA(S)).

RESULTS

PTSD was related to shorter time to lapse (hazard ratio [HR] = 1.677, 95% CI: 1.106-2.544). Increased smoking abstinence self-efficacy was related to longer time to lapse (HR = 0.608, 95% CI: 0.430-0.860). Analyses of participants' real-time reports revealed that smokers with PTSD were more likely to attribute first-time lapses to negative affect ( = 5.412, p = .020), and trauma reminders (Fisher's exact p = .003**). Finally, the quit date decrease in DHEA(S) was related to shorter time to lapse (HR = 1.009, 95% CI: 1.000-1.018, p < .05).

CONCLUSIONS

Results provide evidence of shorter time to first smoking lapse in PTSD, and add to evidence that early lapse occasions are more strongly related to trauma reminders, negative affect, and cravings in smokers with PTSD.

Role of cigarette sensory cues in modifying puffing topography

BACKGROUND

Human puffing topography promotes tobacco dependence by ensuring nicotine delivery, but the factors that determine puffing behavior are not well explained by existing models. Chemosensory cues generated by variations in cigarette product design features may serve as conditioned cues to allow the smoker to optimize nicotine delivery by adjusting puffing topography. Internal tobacco industry research documents were reviewed to understand the influence of sensory cues on puffing topography, and to examine how the tobacco industry has designed cigarettes, including modified risk tobacco products (MRTPs), to enhance puffing behavior to optimize nicotine delivery and product acceptability.

METHODS

Relevant internal tobacco industry documents were identified using systematic searching with key search terms and phrases, and then snowball sampling method was applied to establish further search terms.

RESULTS

Modern cigarettes are designed by cigarette manufacturers to provide sensory characteristics that not only maintain appeal, but provide cues which inform puffing intensity. Alterations in the chemosensory cues provided in tobacco smoke play an important role in modifying smoking behavior independently of the central effects of nicotine.

CONCLUSIONS

An associative learning model is proposed to explain the influence of chemosensory cues on variation in puffing topography. These cues are delivered via tobacco smoke and are moderated by design features and additives used in cigarettes. The implications for regulation of design features of modified risk tobacco products, which may act to promote intensive puffing while lowering risk perceptions, are discussed.

Separate and combined effects of very low nicotine cigarettes and nicotine replacement in smokers with schizophrenia and controls

INTRODUCTION

The prevalence of smoking among people with schizophrenia in the United States is about 3 times that of the general population. Novel approaches are needed to reduce rates of smoking-related morbidity and mortality among these smokers.

METHODS

This study used a within-subjects design to investigate the separate and combined effects of sensorimotor replacement for smoking (very low nicotine content [VLNC] cigarettes vs. no cigarettes) and transdermal nicotine replacement (42 mg nicotine [NIC] vs. placebo [PLA] patches) in smokers with schizophrenia (SS; n = 30) and control smokers without psychiatric illness (CS; n = 26). Each session contained a 5-hr controlled administration period in which participants underwent the following conditions, in counterbalanced order: VLNC + NIC, VLNC + PLA, no cigarettes + NIC, no cigarettes + PLA, usual-brand cigarettes + no patches. Next, participants completed measures of cigarette craving, nicotine withdrawal, smoking habit withdrawal, and cigarette subjective effects, followed by a 90-min period of ad libitum usual-brand smoking.

RESULTS

Smoking VLNC cigarettes during the controlled administration periods reduced cigarette craving, nicotine withdrawal symptoms, habit withdrawal symptoms, and usual-brand smoking in SS and CS relative to the no cigarette conditions. VLNC cigarettes were well accepted by both groups and did not affect psychiatric symptom levels in SS. Transdermal nicotine significantly reduced cigarette craving but did not affect usual-brand smoking.

CONCLUSIONS

These findings suggest that reducing the nicotine content of cigarettes to nonaddictive levels may be a promising approach for reducing nicotine dependence among people with schizophrenia.

Agonist replacement therapy for cocaine dependence: a translational review

Cocaine use disorders are prevalent throughout the world. Agonist replacement therapy is among the most effective strategies for managing substance use disorders including nicotine and opioid dependence. This paper reviews the translational literature, including preclinical experiments, human laboratory studies and clinical trials, to determine whether agonist-replacement therapy is a viable strategy for managing cocaine dependence. Discussion is limited to transporter blockers (i.e., methylphenidate) and releasers (i.e., amphetamine analogs) that are available for use in humans in the hope of impacting clinical research and practice more quickly. The translational review suggests that agonist-replacement therapy, especially monoamine releasers, may be effective for managing cocaine dependence. Future directions for medications development are also discussed because the viability of agonist-replacement therapy for cocaine dependence may hinge on identifying novel compounds or formulations that have less abuse and diversion potential.

The effects of extended pre-quit varenicline treatment on smoking behavior and short-term abstinence: a randomized clinical trial

Preclinical research and learning theory suggest that a longer duration of varenicline treatment prior to the target quit date (TQD) would reduce smoking rates before cessation and improve abstinence outcomes. A double-blind randomized controlled trial tested this hypothesis in 60 smokers randomized to either an Extended run-in group (4 weeks of pre-TQD varenicline) or a Standard run-in group (3 weeks of placebo, 1 week of pre-TQD varenicline); all the participants received 11 weeks of post-TQD varenicline and brief counseling. During the pre-quit run-in, the reduction in smoking rates was greater in the Extended run-in group than in the Standard run-in group (42% vs. 24%, P < 0.01), and this effect was greater in women than in men (57% vs. 26%, P = 0.001). The rate of continuous abstinence during the final 4 weeks of treatment was higher among women in the Extended group compared to women in the Standard run-in group (67% vs. 35%). Although these data suggest that extension of varenicline treatment reduces smoking during the pre-quit period and may further enhance cessation rates, confirmatory evidence is needed from phase III clinical trials.

Smoking withdrawal in smokers with and without posttraumatic stress disorder

INTRODUCTION

Previous research on smoking withdrawal in posttraumatic stress disorder (PTSD) has been limited by the use of retrospective and observational methods and has lacked repeated assessments on the first day of abstinence and evaluation of the conditioned effects of smoking.

METHODS

Smokers with (n = 17; 59% female) and without (n = 30; 17% female) PTSD completed 3 randomly ordered experimental sessions using a 2 (group: PTSD vs. non-PTSD) × 3 (smoking condition: usual brand vs. nicotine free vs. no smoking) design. Before the smoking manipulation, participants completed self-report measures of smoking urges and withdrawal, followed by withdrawal assessment after the smoking manipulation.

RESULTS

Compared with smokers without PTSD, smokers with PTSD exhibited higher craving (χ₁² = 16.60, p < .001) and habit withdrawal (χ₁² = 10.38, p = .001) following overnight abstinence. PTSD smokers also exhibited worsening negative affect throughout the morning when not smoking a cigarette (χ₁² = 11.30, p = .004). After smoking, smokers with PTSD reported diminished relief from craving (χ₁² = 6.49, p = .011), negative affect (χ₁² = 4.51, p = .034), arousal (χ₁² = 6.46, p = .011), and habit withdrawal (χ₁² = 7.22, p = .007), relative to smokers without PTSD.

CONCLUSIONS

Results of this preliminary investigation suggested that after overnight abstinence, PTSD smokers experienced worse withdrawal symptoms and greater urges to smoke for both positive and negative reinforcement. Research on smoking withdrawal early in the course of smoking abstinence in PTSD could inform interventions targeting abstinence early in the quit attempt.

Use of nicotine replacement after a smoking lapse

INTRODUCTION

Current labeling for nicotine replacement therapy (NRT) in the United States and many countries discourages continued use of NRT after a lapse; however, recent studies and consensus statements conclude that continuing NRT postlapse substantially increases long-term abstinence. What percent of clinicians recommend continuation of NRT upon a lapse and what percent of NRT users continue NRT postlapse are unclear.

METHODS

The author queried 24 treatment smoking cessation programs or providers, treatment protocols, directors of quitlines and state programs, published treatment texts, and self-help manuals, books, and Internet sites. The author also recruited 101 current smokers who had attempted to stop smoking in the last 3 months and lapsed while using NRT to complete a survey via an E-mail invitation to an Internet consumer database (www.zoomerang.com).

RESULTS

Most programs and providers (67%) did not discuss use of NRT postlapse, and only 8% recommended continuing NRT postlapse. Among recent quitters using NRT, about one fourth (27%) stopped NRT on the day of the lapse, and one fourth (25%) used NRT for only 1 or 2 days postlapse. Most (73%) reported that use of NRT postlapse was helpful.

DISCUSSION

In summary, advice to use NRT postlapse and actual use of NRT for several days postlapse are uncommon.

The effect of menthol vapor on nasal sensitivity to chemical irritation

INTRODUCTION

Among other effects, menthol added to cigarettes may modulate sensory response to cigarette smoke either by masking "harshness" or contributing to a desirable "impact." However, harshness and impact have been imprecisely defined and assessed using subjective measures. Thus, the current experiments used an objective measure of sensitivity to chemical irritation in the nose to test the hypothesis that menthol vapor modulates sensitivity to chemical irritation in the airways.

METHODS

Nasal irritation thresholds were measured for 2 model compounds (acetic acid and allyl isothiocyanate) using nasal lateralization. In this technique, participants simultaneously sniff clean air in one nostril and chemical vapor in the other and attempt to identify the stimulated nostril. People cannot lateralize based on smell alone but can do so when chemicals are strong enough to feel. In one condition, participants were pretreated by sniffing menthol vapor. In a control condition, participants were pretreated by sniffing an odorless blank (within-subjects design).

RESULTS

Pretreatment with menthol vapor decreased sensitivity to nasal irritation from acetic acid (participants required higher concentrations to lateralize) but increased sensitivity to allyl isothiocyanate (lower concentrations were required).

CONCLUSIONS

The current experiments provide objective evidence that menthol vapor can modulate sensitivity to chemical irritation in the upper airways in humans. Cigarette smoke is a complex mixture of chemicals and particulates, and further work will be needed to determine exactly how menthol modulates smoking sensation. A better understanding could lead to treatments tailored to help menthol smokers quit by replacing the sensation of mentholated cigarettes.

Sensory properties of menthol and smoking topography

Although there is a great deal known about menthol as a flavoring agent in foods and confections, less is known about the particular sensory properties of menthol cigarette smoke. Similarly, although smoking topography (the unique way an individual smokes a cigarette) has been well studied using non-menthol cigarettes, there is relatively less known about how menthol affects smoking behavior. The objective of this review is to assess the sensory properties of menthol tobacco smoke, and smoking topography associated with menthol cigarettes. The cooling, analgesic, taste, and respiratory effects of menthol are well established, and studies have indicated that menthol’s sensory attributes can have an influence on the positive, or rewarding, properties associated smoking, including ratings of satisfaction, taste, perceived smoothness, and perceived irritation. Despite these sensory properties, the data regarding menthol’s effect on smoking topography are inconsistent. Many of the topography studies have limitations due to various methodological issues.

Effect of bupropion treatment on brain activation induced by cigarette-related cues in smokers

CONTEXT

Nicotine-dependent smokers exhibit craving and brain activation in the prefrontal and limbic regions when presented with cigarette-related cues. Bupropion hydrochloride treatment reduces cue-induced craving in cigarette smokers; however, the mechanism by which bupropion exerts this effect has not yet been described.

OBJECTIVE

To assess changes in regional brain activation in response to cigarette-related cues from before to after treatment with bupropion (vs placebo).

DESIGN

Randomized, double-blind, before-after controlled trial.

SETTING

Academic brain imaging center.

PARTICIPANTS

Thirty nicotine-dependent smokers (paid volunteers).

INTERVENTIONS

Participants were randomly assigned to receive 8 weeks of treatment with either bupropion or a matching placebo pill (double-blind).

MAIN OUTCOME MEASURES

Subjective cigarette craving ratings and regional brain activations (blood oxygen level-dependent response) in response to viewing cue videos.

RESULTS

Bupropion-treated participants reported less craving and exhibited reduced activation in the left ventral striatum, right medial orbitofrontal cortex, and bilateral anterior cingulate cortex from before to after treatment when actively resisting craving compared with placebo-treated participants. When resisting craving, reduction in self-reported craving correlated with reduced regional brain activation in the bilateral medial orbitofrontal and left anterior cingulate cortices in all participants.

CONCLUSIONS

Treatment with bupropion is associated with improved ability to resist cue-induced craving and a reduction in cue-induced activation of limbic and prefrontal brain regions, while a reduction in craving, regardless of treatment type, is associated with reduced activation in prefrontal brain regions.

The effect of nicotine and trauma context on acoustic startle in smokers with and without posttraumatic stress disorder

RATIONALE

Exaggerated startle response is a prominent feature of posttraumatic stress disorder (PTSD) although results examining differences in the acoustic startle response (ASR) between those with and without PTSD are mixed. One variable that may affect ASR among persons with PTSD is smoking. Individuals with PTSD are more likely to smoke and have greater difficulty quitting smoking. While smokers with PTSD report that smoking provides significant relief of negative affect and PTSD symptoms, the effects of smoking or nicotine deprivation on startle reactivity among smokers with PTSD are unknown.

OBJECTIVES

The purposes of the current study were to (1) examine baseline acoustic startle response (ASR) in smokers with and without PTSD under conditions of overnight abstinence, (2) evaluate the effect of smoking on ASR, and (3) evaluate the contextual effects of trauma versus neutral script presentations.

METHODS

ASR was measured among 48 smokers with and without PTSD in the context of a 2 (group: PTSD vs. non-PTSD) x 2 (context: trauma vs. neutral) x 3 (smoking condition: usual brand cigarette vs. denicotinized cigarette vs. no smoking) design.

RESULTS

Effects of modest size indicated that (1) PTSD participants demonstrated higher ASR (2) compared to non-PTSD participants, PTSD participants reported greater negative affect following a trauma-related script, and (3) following a trauma-related script and smoking a usual brand cigarette, PTSD participants demonstrated higher ASR.

CONCLUSIONS

Although many smokers with PTSD report that smoking reduces PTSD symptoms, results suggest that smoking may actually potentiate or maintain an exaggerated startle response.

The role of menthol in cigarettes as a reinforcer of smoking behavior

INTRODUCTION

The World Health Organization has identified several additives such as menthol in the manufacturing of cigarettes to specifically reduce smoke harshness. These additives may have important implications for reinforcing smoking behavior and motivation to quit smoking. The purpose of this paper is to synthesize research related to the role of menthol's sensory characteristics in strengthening the reinforcing effects of nicotine in cigarettes and the impact on nicotine addiction and smoking behavior.

METHODS

Research reports from 2002 to 2010 on the addictive potential of menthol cigarettes were reviewed that included qualitative focus groups, self-reports and biomarkers of nicotine dependence, human laboratory, and epidemiological studies.

RESULTS

Positive sensory effects of menthol cigarette use were identified via reports of early smoking experiences and as a potential starter product for smoking uptake in youth. Menthol cigarettes may serve as a conditioned stimulus that reinforces the rewarding effects of smoking. Nicotine dependence measured by shorter time-to-first cigarette upon waking was increased with menthol cigarette use in most of the studies reviewed. Smoking quit rates provide additional indicators of nicotine dependence, and the majority of the studies reviewed provided evidence of lower quit rates or higher relapse rates among menthol cigarette smokers.

CONCLUSIONS

The effects of menthol cigarette use in increasing the reinforcing effects of nicotine on smoking behavior were evidenced in both qualitative and quantitative empirical studies. These findings have implications for enhanced prevention and cessation efforts in menthol smokers.

Brain β2*-nicotinic acetylcholine receptor occupancy after use of a nicotine inhaler

The Nicotrol® (Pfizer, USA) nicotine inhaler reduces craving by mimicking the behavioural component of cigarettes and delivering controlled doses of nicotine, which binds to the beta-2 subunit-containing nicotinic acetylcholine receptors (β2*-nAChRs). Previous studies examined β2*-nAChR occupancy after administration of regular and low-nicotine cigarettes. Here, we measured occupancy of β2*-nAChRs after administration of nicotine via inhaler, and the relationship between occupancy and changes in craving for tobacco smoking and withdrawal symptoms. Tobacco smokers participated in [123I]5-IA-85380 SPECT studies with either a nicotine inhaler (n=9) or tobacco cigarette (n=4) challenge. [123I]5-IA was administered as a bolus plus constant infusion. After equilibrium was achieved, three 30-min baseline scans were collected, and subjects either used the nicotine inhaler or a regular cigarette, and up to six additional scans were obtained. Receptor occupancy was determined based on the Lassen plot method. Craving for tobacco smoking and withdrawal symptoms were evaluated pre- and post-challenge. Use of the nicotine inhaler produced an average 55.9±6.4% occupancy of β2*-nAChRs 2-5 h post-challenge, whereas use of a cigarette produced significantly higher receptor occupancy (F=10.6, p=0.009) with an average 67.6±14.1% occupancy 1.5-5 h post-challenge. There was a significant decrease in withdrawal symptoms post-nicotine inhaler use (F=6.13, p=0.04). These results demonstrate significant differences in occupancy of β2*-nAChRs by nicotine after use of the inhaler vs. a cigarette and confirm the ability of the nicotine inhaler to relieve withdrawal symptoms.

Impact of self-initiated pre-quit smoking reduction on cessation rates: results of a clinical trial of smoking cessation among female prisoners

OBJECTIVES

This study examined differences in cessation success based on smokers' self-initiated pre-quit reductions in cigarettes per day (cpd).

METHODS

The study utilized data from a nicotine replacement+behavioral therapy smoking cessation intervention conducted in a female prison facility with 179 participants who were wait-listed for 6 months prior to intervention. We compared two groups of smokers based on whether they self-selected to reduce smoking prior to their cessation attempt (n=77) or whether they increased smoking or did not reduce (n=102). General Estimating Equations (GEE) were used to model smoking cessation through 12-month follow-up.

RESULTS

Examination of pre-cessation cpd showed that those who reduced were heavier smokers at baseline, relative to those who did not reduce (p<0.001). By the week prior to the quit attempt (week 3) heavier smokers at baseline smoked significantly fewer cigarettes (p<0.001) and had lower CO levels (p<0.05) compared to baseline lighter smokers. GEE analyses showed that individuals who reduced prior to their quit attempt had significantly higher quit rates during early treatment but these gains were not sustained by follow-up points.

CONCLUSIONS

Participant-initiated pre-cessation smoking reduction may be initially helpful in preparing to quit smoking, or may serve as a marker for participant motivation to quit smoking, but these differences do not sustain over time. More intensive interventions are still needed for successful cessation.

Reinforcing effects of nicotine and non-nicotine components of cigarette smoke

RATIONALE

Nicotine and non-nicotine components of cigarette smoke contribute to its reinforcing effects; however, the specific role of each component in maintaining behavior has not yet been elucidated.

OBJECTIVES

To assess the reinforcing effects of nicotine and non-nicotine components of cigarette smoke by presenting a concurrent choice paradigm in which participants had access to intravenous (IV) nicotine infusions vs. saline (placebo) infusions and puffs from denicotinized ("denic") cigarettes vs. air (sham puffs). We also measured the effects on self-administration of prior satiation with each component.

METHODS

Sixteen smokers participated in seven sessions: 1) a baseline smoking assessment, used to tailor the nicotine dose per infusion; 2) two sessions for training discrimination of IV nicotine vs. saline infusions and denic smoke vs. sham puffs; and 3) four sessions assessing choice behavior after different satiation conditions.

RESULTS

Denic smoke was self-administered more than any other alternative, including IV nicotine. IV nicotine, however, was preferred over IV saline and sham puffs. Preference for denic smoke vs. IV nicotine was inversely correlated with subjective ratings of "comfort" associated with nicotine. Smoke satiation reduced the number of denic puffs taken during choice periods, while prior nicotine administration did not affect puffing behavior. Smoking withdrawal symptoms were alleviated both by nicotine administration and by denic smoke.

CONCLUSIONS

In established smokers, non-nicotine aspects of cigarette smoking have potent reinforcing effects. While current smoking cessation pharmacotherapies primarily address the nicotine component of cigarette addiction, future cessation strategies should also be designed to target non-nicotine factors.

Agonist-like pharmacotherapy for stimulant dependence: preclinical, human laboratory, and clinical studies

A variety of natural and synthetic agents have long been used for stimulant properties, with nontherapeutic use producing multiple waves of stimulant abuse and dependence. The multitude of effects of stimulants exist on continua, and accordingly, here we characterize stimulant abuse/dependence and candidate pharmacotherapies in this manner. Behavioral therapy and medications have been investigated for treatment of stimulant abuse/dependence. Effectiveness of some behavioral interventions has been demonstrated. Most medications studied have been found to lack efficacy. However, an expanding literature supports use of agonist-like medications to treat stimulant abuse/dependence, a strategy effective for nicotine and opiate dependence. The agonist-like conceptualization for stimulant dependence posits that medications with properties similar to that of the abused drug, but possessing lesser abuse liability, will normalize neurochemistry and stabilize behavior, thus reducing drug use. Data suggest use of a range of medications, from l-dopa/carbidopa to amphetamine preparations, depending on the severity of use. This report reviews preclinical, human laboratory, and clinical trial data supporting the agonist-like approach, including risks and benefits. Future directions for development of agonist-like medications are also discussed.

A review and assessment of menthol employed as a cigarette flavoring ingredient

Cigarette smoking is established as a substantial contributor to risks for cancer, cardiovascular and respiratory diseases. Less is known about the potential of cigarette composition to affect smoking risks. The use of cigarette flavoring ingredients such as menthol is currently of worldwide public health and regulatory interest. The unique conditions of menthol inhalation exposure that occur coincident with that of the complex cigarette smoke aerosol require specialized studies to support an assessment of its safety in cigarette flavoring applications. The present state of knowledge is sufficient to support an assessment of the safety of the use of menthol in cigarettes. Scientific, smoking behavioral and epidemiological data available through mid-2009 is critically reviewed and a broad convergence of findings supports a judgment that menthol employed as a cigarette tobacco flavoring ingredient does not meaningfully affect the inherent toxicity of cigarette smoke or the human risks that attend smoking. There remains a need for well-designed studies of the potential of menthol to affect smoking initiation, cessation and addiction in order to differentiate any independent effects of menthol in cigarettes from those imposed by socioeconomic, environmental and peer influences on these complex human behaviors.

D-Cycloserine attenuates reactivity to smoking cues in nicotine dependent smokers: a pilot investigation

Increasing evidence indicates that smoking cues contribute to nicotine self-administration and attenuating conditioned reactivity to smoking cues may aid abstinence of smoking and prevention of smoking relapse in individuals with nicotine dependence. Based on prior studies showing that the partial N-methyl-D-aspartate (NMDA) agonist D-cycloserine (DCS) facilitates extinction of learned fear during behavioral exposure therapy in humans and facilitates extinction of cocaine-induced conditioned place preference in animals, we evaluated whether DCS would have potential for reducing reactivity to smoking cues when combined with cue exposure treatment in humans with nicotine dependence. In this double-blind placebo-controlled pilot laboratory study, 25 smokers were recruited from the general community and randomized to DCS or placebo, plus cue exposure therapy. DCS significantly attenuated smoking cue reactivity in response to in-vivo smoking cues based on physiological reactivity and subjective urge-to-smoke ratings and led to a significantly smaller expired carbon monoxide (CO) level at the one-week follow-up compared to placebo, although exploratory analyses indicated no effect on smoking behavior overall. These findings provide promising support for DCS combined with cue exposure therapy in attenuating conditioned reactivity to smoking cues.

Tobacco smoking produces widespread dominant brain wave alpha frequency increases

The major pharmacological ingredient in tobacco smoke is nicotine, a mild stimulant known to alter brain electrical activity. The objective of this study was to determine if tobacco smoking in humans produces localized or widespread neocortical dominant alpha electroencephalographic (EEG) frequency increases consistent with nicotine stimulation of the brainstem activating system in animals. Twenty-two male volunteer non-deprived tobacco smokers were studied. They were asked not to smoke for at least 1h before the experiment in mid-morning as part of their usual smoking schedule. In the laboratory, they sham smoked and then smoked their favorite tobacco cigarette. Two experimental sessions (#1 and #2) were conducted, separated by a one to two month interval. In both sessions, there were minor statistically significant increases in the dominant alpha frequencies after sham smoking. In both sessions, after the subjects smoked a favorite tobacco cigarette there was a significant generalized increase in dominant alpha EEG frequencies in most scalp recording sites. This study demonstrates that tobacco smoking produces widespread bilateral neocortical increases in dominant alpha EEG frequencies consistent with the stimulant effects of nicotine on the brainstem reticular activating system.

Prolonged exposure to denicotinized cigarettes with or without transdermal nicotine

Sensorimotor smoking stimuli are important determinants of cigarette use. The present study aimed to determine whether denicotinized cigarettes lose their reinforcing and/or subjective effects over a 9-day outpatient period when they are smoked with or without concurrent transdermal nicotine. After a preferred brand baseline, 68 participants were randomized into one of four conditions based on the dose (mg) of transdermal nicotine and the type of cigarettes (dose/cigarette): 0/nicotine, 0/denicotinized, 7/denicotinized, and 21/denicotinized. Under placebo patch conditions, participants smoked a similar number of nicotine and denicotinized cigarettes and no group differences emerged over repeated testing. The total volume of smoke inhaled was lower in the denicotinized group, although this decrease dissipated over time. Denicotinized cigarettes were rated as having low positive and high negative subjective effects. Compared to placebo, transdermal nicotine decreased the number of denicotinized cigarette smoked, produced a lasting decrease in the total volume of denicotinized cigarette smoke inhaled, but had little effect on the subjective effects of denicotinized cigarettes. Transdermal nicotine attenuated withdrawal during initial smoking abstinence; however, once participants were allowed to smoke withdrawal symptoms were relatively low regardless of patch condition. The persistent use of denicotinized cigarettes may result from the presence of nicotine withdrawal and/or the degree to which smoking becomes somewhat independent of the outcome of the behavior (i.e., habit learning). Additional studies would be useful to determine what factors drive continued use of denicotinized cigarettes, whether their use subsides as withdrawal dissipates, and whether they address motives for smoking distinct from current pharmacotherapy.

Precessation treatment with nicotine patch significantly increases abstinence rates relative to conventional treatment

INTRODUCTION

Previous studies have reported that smoking abstinence rates are increased when nicotine skin patch treatment is initiated prior to the target quit smoking date, as compared with conventional treatment beginning on the quit date. We hypothesized that smoking in the presence of continuous levels of nicotine would attenuate the reinforcing effects of cigarette smoking and lead to a decline in dependence on inhaled nicotine, thus facilitating cessation.

METHODS

This study involved four groups of smokers (n = 100 per group) who received either nicotine patch (21 mg/24 hr) or placebo patch treatment for 2 weeks before the quit smoking date, and during this period, smoked their usual brands of cigarettes or switched to low-tar and nicotine cigarettes: a 2 (nicotine patch) x 2 (cigarette type) factorial design. From the quit date on, all groups received standard nicotine patch treatment, consisting of 6 weeks of 21 mg/24 hr, 2 weeks of 14 mg/24 hr, and 2 weeks of 7 mg/24 hr. Abstinence was defined as self-report of no smoking from the quit date on, confirmed by expired-air carbon monoxide.

RESULTS

Continuous abstinence rates were approximately doubled by precessation nicotine patch treatment. The treatment mainly benefited smokers with lower levels of dependence, based on Fagerström Test for Nicotine Dependence score. All treatments were well tolerated.

DISCUSSION

In view of these findings and similar results from previous studies, current labeling of the nicotine patch, which recommends using nicotine replacement therapy only after the quit date, should be reexamined.

Quitting by gradual smoking reduction using nicotine gum: a randomized controlled trial

BACKGROUND

Many smokers express a desire to quit smoking by gradually reducing the number of cigarettes they smoke until they stop completely. This study tested the efficacy of nicotine gum in facilitating cessation through gradual reduction.

DESIGN

This was a multi-center, placebo-controlled, double-blind RCT of 2- and 4-mg nicotine gum versus placebo.

SETTING/PARTICIPANTS

3297 smokers who were interested in quitting gradually.

INTERVENTION

Subjects were instructed to gradually reduce their smoking while increasing their gum use over the course of up to 8 weeks. Once they had achieved initial abstinence (no smoking for 24 hours), gum was to be used in accordance with the current FDA-approved directions for cessation. The study was conducted under over-the-counter conditions, with no counseling provided. Continuous abstinence was assessed after 28 days and 6 months. Secondary measures of smoking reduction were also assessed. Analyses were conducted in 1999-2000 and 2007-2008.

MAIN OUTCOME MEASURES

Smokers on active gum were significantly more likely to achieve initial cessation (2 mg: OR=1.42; 4 mg: OR=1.90); 28-day continuous abstinence (2 mg: OR=2.01; 4 mg: OR=4.66); and continuous abstinence at 6 months (2 mg: OR=1.80; 4 mg: OR=5.96). During the reduction phase, active gum aided smoking reduction, and participants who reduced their smoking were more likely to achieve abstinence.

CONCLUSIONS

These findings demonstrate that smokers who wish to quit smoking by gradual reduction can increase their success by using nicotine gum to facilitate reduction and cessation.

Disrupting nicotine reinforcement: from cigarette to brain

Cigarette smoking is a tenacious addiction that is maintained to a significant extent by the reinforcing effects of nicotine. An emerging theme in smoking cessation treatment is the development of methods for interfering with these reinforcing effects. By attenuating nicotine reinforcement, treatments may enhance a smoker's chances of successfully remaining abstinent. Several treatment approaches will be described, including the use of denicotinized cigarettes, nicotine vaccines, nicotinic receptor agonists and antagonists, and modulators of brain reinforcement processes. These techniques highlight the numerous sites along the path between the cigarette and the brain that can be targeted for intervention. In addition to unimodal therapies, treatment combinations will be discussed that might more effectively block cigarette reward and thereby further enhance smoking abstinence.

Influence of Neuronal Nicotinic Receptors over Nicotine Addiction and Withdrawal

Cigarette smoking represents an enormous, global public health threat. Nearly five million premature deaths during a single year are attributable to smoking. Despite the resounding message of risks associated with smoking and numerous public health initiatives, cigarette smoking remains the most common preventable cause of disease in the United States. Fortunately, even in an adult smoker, smoking cessation can reverse many of the potential harmful effects. The symptoms associated with nicotine withdrawal represent the major obstacle to smoking cessation. This minireview examines the roles of various nicotinic receptors in the mechanisms of nicotine dependence, discusses the potential role of the habenula-interpeduncular nucleus axis in nicotine withdrawal, and highlights nicotinic receptors containing the β4 subunit as a potential pharmacological target for smoking cessation strategies.