Multimodal techniques for smoking cessation: a review of their efficacy and utilisation and clinical practice guidelines

α-Conotoxin TxID and [S9K]TxID, α3β4 nAChR Antagonists, Attenuate Expression and Reinstatement of Nicotine-Induced Conditioned Place Preference in Mice

Tobacco smoking has become a prominent health problem faced around the world. The α3β4 nicotinic acetylcholine receptor (nAChR) is strongly associated with nicotine reward and withdrawal symptom. α-Conotoxin TxID, cloned from Conus textile, is a strong α3β4 nAChR antagonist, which has weak inhibition activity of α6/α3β4 nAChR. Meanwhile, its analogue [S9K]TxID only inhibits α3β4 nAChR (IC₅₀ = 6.9 nM), and has no inhibitory activity to other nAChRs. The present experiment investigates the effect of α3β4 nAChR antagonists (TxID and [S9K]TxID) on the expression and reinstatement of nicotine-induced conditioned place preference (CPP) and explores the behaviors of acute nicotine in mice. The animal experimental results showed that TxID and [S9K] TxID could inhibit the expression and reinstatement of CPP, respectively. Moreover, both had no effect in acute nicotine experiment and the locomotor activity in mice. Therefore, these findings reveal that the α3β4 nAChR may be a potential target for anti-nicotine addiction treatment. [S9K]TxID, α3β4 nAChR antagonist, exhibit a superior effect for anti-nicotine addiction, which is promising to develop a novel smoking cessation drug.

Not Just a Pill: Toward a Tailored Antismoking Intervention for Respiratory Diseases

Tobacco cigarette smoking is a serious epidemic that kills several million people each year. Nevertheless, a significant percentage of patients with respiratory diseases continue to smoke after diagnosis, despite the assistance offered, thus reducing the efficacy of the treatments prescribed by the health providers and dramatically increasing the mortality rate. International guidelines have advocated the importance of including smoking cessation protocols in the management of patients' respiratory conditions and pointed out the need to deliver integrated and tailored interventions. Consistently with this framework, the commentary proposes a new clinical approach to smoking cessation in patients with respiratory diseases. This approach integrates, according to P5 personalized medicine, pharmacological and psychological aspects affecting smoking behaviors, overcoming the traditional approach mainly based on the pharmacological interventions.

An Office-Initiated Multilevel Intervention for Tobacco Smoke Exposure: A Randomized Trial

BACKGROUND

Provider adherence to best practice guidelines (ask, advise, refer [AAR]) for addressing child tobacco smoke exposure (TSE) motivates parents to reduce TSE. However, high-risk, vulnerable populations of smokers may require more intensive treatment. We hypothesized that a pragmatic, multilevel treatment model including AAR coupled with individualized, telephone-based behavioral counseling promoting child TSE reduction would demonstrate greater child TSE reduction than would standard AAR.

METHODS

In this 2-arm randomized controlled trial, we trained pediatric providers in systems serving low-income communities to improve AAR adherence by using decision aid prompts embedded in routine electronic health record assessments. Providers faxed referrals to the study and received ongoing AAR adherence feedback. Referred participants were eligible if they were daily smokers, >17 years old, and spoke English. Participants were randomly assigned to telephone-based behavioral counseling (AAR and counseling) or nutrition education (AAR and attention control). Participants completed prerandomization and 3-month follow-up assessments.

RESULTS

Of providers, >80% (n = 334) adhered to AAR procedures and faxed 2949 referrals. Participants (n = 327) were 83% women, 83% African American, and 79% low income (below poverty level). Intention-to-treat logistic regression showed robust, positive treatment effects: more parents in AAR and counseling than in AAR and attention control eliminated all sources of TSE (45.8% vs 29.9%; odds ratio 1.99 [95% confidence interval 1.44-2.74]) and quit smoking (28.2% vs 8.2%; odds ratio 3.78 [95% confidence interval 1.51-9.52]).

CONCLUSIONS

The results indicate that the integration of clinic- and individual-level smoking interventions produces improved TSE and cessation outcomes relative to standalone clinic AAR intervention. Moreover, this study was among the first in which researchers demonstrated success in embedding AAR decision aids into electronic health records and seamlessly facilitated TSE intervention into routine clinic practice.

Highly Selective and Potent α4β2 nAChR Antagonist Inhibits Nicotine Self-Administration and Reinstatement in Rats

The α4β2 nAChR is the most predominant subtype in the brain and is a well-known culprit for nicotine addiction. Previously we presented a series of α4β2 nAChR selective compounds that were discovered from a mixture-based positional-scanning combinatorial library. Here we report further optimization identified highly potent and selective α4β2 nAChR antagonists 5 (AP-202) and 13 (AP-211). Both compounds are devoid of in vitro agonist activity and are potent inhibitors of epibatidine-induced changes in membrane potential in cells containing α4β2 nAChR, with IC₅₀ values of approximately 10 nM, but are weak agonists in cells containing α3β4 nAChR. In vivo studies show that 5 can significantly reduce operant nicotine self-administration and nicotine relapse-like behavior in rats at doses of 0.3 and 1 mg/kg. The pharmacokinetic data also indicate that 5, via sc administration, is rapidly absorbed into the blood, reaching maximal concentration within 10 min with a half-life of less than 1 h.

The α3β4 nAChR partial agonist AT-1001 attenuates stress-induced reinstatement of nicotine seeking in a rat model of relapse and induces minimal withdrawal in dependent rats

The strong reinforcing effects of nicotine and the negative symptoms such as anxiety experienced during a quit attempt often lead to relapse and low success rates for smoking cessation. Treatments that not only block the reinforcing effects of nicotine but also attenuate the motivation to relapse are needed to improve cessation rates. Recent genetic and preclinical studies have highlighted the involvement of the α3, β4, and α5 nicotinic acetylcholine receptor (nAChR) subunits and the α3β4 nAChR subtype in nicotine dependence and withdrawal. However, the involvement of these nAChR in relapse is not fully understood. We previously reported that the α3β4 nAChR partial agonist AT-1001 selectively decreases nicotine self-administration in rats without affecting food responding. In the present experiments, we examined the efficacy of AT-1001 in attenuating reinstatement of nicotine-seeking behavior in a model of stress-induced relapse. Rats extinguished from nicotine self-administration were treated with the pharmacological stressor yohimbine prior to AT-1001 treatment and reinstatement testing. We also examined whether AT-1001 produced any withdrawal-related effects when administered to nicotine-dependent rats. We found that AT-1001 dose-dependently reduced yohimbine stress-induced reinstatement of nicotine seeking. When administered to nicotine-dependent rats at the dose that significantly blocked nicotine reinstatement, AT-1001 elicited minimal somatic withdrawal signs in comparison to the nicotinic antagonist mecamylamine, which is known to produce robust withdrawal. Our data suggest that α3β4 nAChR-targeted compounds may be a promising approach for nicotine addiction treatment because they can not only block nicotine's reinforcing effects, but also decrease motivation to relapse without producing significant withdrawal effects.

Babies Living Safe & Smokefree: randomized controlled trial of a multilevel multimodal behavioral intervention to reduce low-income children's tobacco smoke exposure

Background

Addressing children’s tobacco smoke exposure (TSE) remains a public health priority. However, there is low uptake and ineffectiveness of treatment, particularly in low-income populations that face numerous challenges to smoking behavior change. A multilevel intervention combining system-level health messaging and advice about TSE delivered at community clinics that disseminate the Special Supplemental Nutrition Program for Women, Infants and Children (WIC), combined with nicotine replacement and intensive multimodal, individual-level behavioral intervention may improve TSE control efforts in such high-risk populations.

Methods/Design

This trial uses a randomized two-group design with three measurement points: baseline, 3-month and 12-month follow-up. The primary outcome is bioverified child TSE; the secondary outcome is bioverified maternal quit status. Smoking mothers of children less than 6 years old are recruited from WIC clinics. All participants receive WIC system-level intervention based on the “Ask, Advise, Refer (AAR)” best practices guidelines for pediatrics clinics. It includes training all WIC staff about the importance of maternal tobacco control; and detailing clinics with AAR intervention prompts in routine work flow to remind WIC nutrition counselors to ask all mothers about child TSE, advise about TSE harms and benefits of protection, and refer smokers to cessation services. After receiving the system intervention, mothers are randomized to receive 3 months of additional treatment or an attention control intervention: (1) The multimodal behavioral intervention (MBI) treatment includes telephone counseling sessions about child TSE reduction and smoking cessation, provision of nicotine replacement therapy, a mobile app to support cessation efforts, and multimedia text messages about TSE and smoking cessation; (2) The attention control intervention offers equivalent contact as the MBI and includes nutrition-focused telephone counseling, mobile app, and multimedia text messages about improving nutrition. The control condition also receives a referral to the state smoking cessation quitline.

Discussion

This study tests an innovative community-based, multilevel and integrated multimodal approach to reducing child TSE in a vulnerable, low-income population. The approach is sustainable and has potential for wide reach because WIC can integrate the tobacco intervention prompts into routine workflow and refer smokers to free evidence-based behavioral counseling interventions, such as state quitlines.

Trial registration

Clinicaltrials.gov NCT02602288. Registered 9 November 2015.

Integrative tobacco cessation: A survey assessing past quit strategies and future interest

PURPOSE

Tobacco cessation remains a public health priority. Unassisted quits are most common despite evidence for a combination of guideline-recommended strategies. This paper reports findings from a pilot study designed to assess past quit strategies and tobacco users' receptiveness to using an integrative clinic that offers both conventional and alternative treatments for future cessation attempts.

METHODS

Participants were recruited from a pool of individuals reporting for jury duty. Paper-pencil surveys assessed smoking, past cessation behaviors, and interest in use of the integrative clinic which offers both conventional and alternative treatments. Current and former smokers (n=304) returned surveys.

RESULTS

Using multivariate logistic regression, past physiological quit strategies, past behavioral quit strategies, and use of multiple quit strategies increased agreement with interest in future use of an integrative clinic option. Additionally, there is support for the notion that if such a clinic were offered, smokers may be inclined to use this resource for a future quit attempt.

CONCLUSIONS

An integrative clinic option for tobacco cessation may encourage smokers to try to quit, especially for those who have used varied cessation strategies in the past. Motivating smokers to use a combined approach for tobacco cessation is a potential future direction for tobacco cessation treatment. Developing and testing an integrative approach may support this effort.

Implementation of a quality improvement project on smoking cessation reduces smoking in a high risk trauma patient population

BACKGROUND

Cigarette smoking causes about one of every five deaths in the U.S. each year. In 2013 the prevalence of smoking in our institution's trauma population was 26.7 %, well above the national adult average of 18.1 % according to the CDC website. As a quality improvement project we implemented a multimodality smoking cessation program in a high-risk trauma population.

METHODS

All smokers with independent mental capacity admitted to our level I trauma center from 6/1/2014 until 3/31/2015 were counseled by a physician on the benefits of smoking cessation. Those who wished to quit smoking were given further counseling by a pulmonary rehabilitation nurse and offered nicotine replacement therapy (e.g. nicotine patch). A planned 30 day or later follow-up was performed to ascertain the primary endpoint of the total number of patients who quit smoking, with a secondary endpoint of reduction in the frequency of smoking, defined as at least a half pack per day reduction from their pre-intervention state.

RESULTS

During the 9 month study period, 1066 trauma patients were admitted with 241 (22.6 %) identified as smokers. A total of 31 patients with a mean Injury Severity Score (ISS) of 14.2 (range 1-38), mean age of 47.6 (21-71) and mean years of smoking of 27.1 (2-55), wished to stop smoking. Seven of the 31 patients, (22.5 %, 95 % confidence interval [CI] of 10-41 %) achieved self-reported smoking cessation at or beyond 30 days post discharge. An additional eight patients (25.8 %, 95 % CI 12-45 %) reported significant reduction in smoking.

CONCLUSIONS

Trauma patients represent a high risk smoking population. The implementation of a smoking cessation program led to a smoking cessation rate of 22.5 % and smoking reduction in 25.8 % of all identified smokers who participated in the program. This is a relatively simple, inexpensive intervention with potentially far reaching and beneficial long-term health implications. A larger, multi-center prospective study appears warranted.

LEVEL OF EVIDENCE

Therapeutic Study, Level V evidence.

Combined pharmacotherapy and behavioural interventions for smoking cessation

BACKGROUND

Both behavioural support (including brief advice and counselling) and pharmacotherapies (including nicotine replacement therapy (NRT), varenicline and bupropion) are effective in helping people to stop smoking. Combining both treatment approaches is recommended where possible, but the size of the treatment effect with different combinations and in different settings and populations is unclear.

OBJECTIVES

To assess the effect of combining behavioural support and medication to aid smoking cessation, compared to a minimal intervention or usual care, and to identify whether there are different effects depending on characteristics of the treatment setting, intervention, population treated, or take-up of treatment.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register in July 2015 for records with any mention of pharmacotherapy, including any type of NRT, bupropion, nortriptyline or varenicline.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials evaluating combinations of pharmacotherapy and behavioural support for smoking cessation, compared to a control receiving usual care or brief advice or less intensive behavioural support. We excluded trials recruiting only pregnant women, trials recruiting only adolescents, and trials with less than six months follow-up.

DATA COLLECTION AND ANALYSIS

Search results were prescreened by one author and inclusion or exclusion of potentially relevant trials was agreed by two authors. Data was extracted by one author and checked by another.The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) and 95% confidence interval (CI) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

Fifty-three studies with a total of more than 25,000 participants met the inclusion criteria. A large proportion of studies recruited people in healthcare settings or with specific health needs. Most studies provided NRT. Behavioural support was typically provided by specialists in cessation counselling, who offered between four and eight contact sessions. The planned maximum duration of contact was typically more than 30 minutes but less than 300 minutes. Overall, studies were at low or unclear risk of bias, and findings were not sensitive to the exclusion of any of the six studies rated at high risk of bias in one domain. One large study (the Lung Health Study) contributed heterogeneity due to a substantially larger treatment effect than seen in other studies (RR 3.88, 95% CI 3.35 to 4.50). Since this study used a particularly intensive intervention which included extended availability of nicotine gum, multiple group sessions and long term maintenance and recycling contacts, the results may not be comparable with the interventions used in other studies, and hence it was not pooled in other analyses. Based on the remaining 52 studies (19,488 participants) there was high quality evidence (using GRADE) for a benefit of combined pharmacotherapy and behavioural treatment compared to usual care, brief advice or less intensive behavioural support (RR 1.83, 95% CI 1.68 to 1.98) with moderate statistical heterogeneity (I² = 36%).The pooled estimate for 43 trials that recruited participants in healthcare settings (RR 1.97, 95% CI 1.79 to 2.18) was higher than for eight trials with community-based recruitment (RR 1.53, 95% CI 1.33 to 1.76). Compared to the first version of the review, previous weak evidence of differences in other subgroup analyses has disappeared. We did not detect differences between subgroups defined by motivation to quit, treatment provider, number or duration of support sessions, or take-up of treatment.

AUTHORS' CONCLUSIONS

Interventions that combine pharmacotherapy and behavioural support increase smoking cessation success compared to a minimal intervention or usual care. Updating this review with an additional 12 studies (5,000 participants) did not materially change the effect estimate. Although trials differed in the details of their populations and interventions, we did not detect any factors that modified treatment effects apart from the recruitment setting. We did not find evidence from indirect comparisons that offering more intensive behavioural support was associated with larger treatment effects.

HIV and smoking: associated risks and prevention strategies

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

Anxiety and Depression in Bidirectional Relations Between Pain and Smoking: Implications for Smoking Cessation

Pain and tobacco smoking are highly prevalent and comorbid conditions that impose considerable burdens on individuals and health care systems. A recently proposed reciprocal model suggests that these conditions interact in a bidirectional manner, resulting in greater pain and the maintenance of tobacco addiction. Anxiety and depression are common among smokers in pain and have been identified as central mechanisms of interest. There is emerging evidence that smokers with anxiety/depression may experience more severe pain and functional impairment, greater pain-induced motivation to smoke, and increased sensitivity to pain during periods of smoking abstinence. Based on empirical findings, we hypothesize that these experiences may engender expectations that abstaining from smoking will exacerbate both pain and negative affect, thus eroding self-efficacy for smoking cessation and increasing perceived barriers to quitting. The goal of this narrative review is to examine the role of anxiety/depression in complex pain-smoking relations so as to advance evolving theoretical perspectives and inform the development of tailored interventions.

Reducing Underserved Children's Exposure to Tobacco Smoke: A Randomized Counseling Trial With Maternal Smokers

INTRODUCTION

Addressing maternal smoking and child tobacco smoke exposure is a public health priority. Standard care advice and self-help materials to help parents reduce child tobacco smoke exposure is not sufficient to promote change in underserved populations. We tested the efficacy of a behavioral counseling approach with underserved maternal smokers to reduce infant's and preschooler's tobacco smoke exposure.

DESIGN

A two-arm randomized trial: enhanced behavior counseling (experimental) versus enhanced standard care (control). Assessment staff members were blinded.

SETTING/PARTICIPANTS

Three hundred randomized maternal smokers were recruited from low-income urban communities. Participants had a child aged <4 years exposed to two or more maternal cigarettes/day at baseline.

INTERVENTION

Philadelphia Family Rules for Establishing Smoke-free Homes (FRESH) included 16 weeks of counseling. Using a behavioral shaping approach within an individualized cognitive-behavioral therapy framework, counseling reinforced efforts to adopt increasingly challenging tobacco smoke exposure-protective behaviors with the eventual goal of establishing a smoke-free home.

MAIN OUTCOME MEASURES

Primary outcomes were end-of-treatment child cotinine and reported tobacco smoke exposure (maternal cigarettes/day exposed). Secondary outcomes were end-of-treatment 7-day point-prevalence self-reported cigarettes smoked/day and bioverified quit status.

RESULTS

Participation in FRESH behavioral counseling was associated with lower child cotinine (β=-0.18, p=0.03) and reported tobacco smoke exposure (β=-0.57, p=0.03) at the end of treatment. Mothers in behavioral counseling smoked fewer cigarettes/day (β=-1.84, p=0.03) and had higher bioverified quit rates compared with controls (13.8% vs 1.9%, χ(2)=10.56, p<0.01). There was no moderating effect of other smokers living at home.

CONCLUSIONS

FRESH behavioral counseling reduces child tobacco smoke exposure and promotes smoking quit rates in a highly distressed and vulnerable population.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT02117947.

Can psychedelic compounds play a part in drug dependence therapy?

After a 40-year hiatus there is now a revisiting of psychedelic drug therapy throughout psychiatry, with studies examining the drugs psilocybin, ketamine, ibogaine and ayahuasca in the treatment of drug dependence. Limitations to these therapies are both clinical and legal, but the possibility of improving outcomes for patients with substance dependency imposes an obligation to research this area.

Comparison of the reinforcing properties of nicotine and cigarette smoke extract in rats

Tobacco dependence is difficult to treat, with the vast majority of those who try to quit relapsing within the first year. Improvements in smoking cessation therapies may be achieved by improving current preclinical research methods. However, most experimental tests in animals use nicotine alone, ignoring the 8000 other constituents found in tobacco smoke. To improve on this model, we have used self-administration to test the reinforcing properties of aqueous cigarette smoke extract (CSE) in rats, made by bubbling cigarette smoke through a saline solution. CSE is more potent than nicotine alone in both the acquisition and maintenance of self-administration, but did not exhibit higher progressive ratio responding. Mecamylamine and varenicline had similar potencies to block nicotine and CSE self-administration, indicating the involvement of nicotinic receptors in CSE reinforcement. Following extinction of responding, reinstatement was triggered by exposing animals to a pharmacological stressor, yohimbine (2.5 mg/kg, i.p.), alone and in combination with cues. Animals that self-administered CSE were significantly more sensitive to stress-induced reinstatement than those that self-administered nicotine. Ligand binding autoradiography studies showed nicotine and CSE to have similar affinities for different nicotinic receptor types. CSE significantly reduced MAO-A and MAO-B activities in vitro, whereas nicotine did not. Although CSE inhibition of MAO-A activity in vitro was found to be partially irreversible, irreversible inhibition was not observed in vivo. These experiments show that CSE is an effective reinforcer acting via nicotinic receptors. Furthermore, it better models MAO inhibition and is more sensitive to stress-induced reinstatement than nicotine alone, which is a potent trigger for relapse in smokers.

Catalytic mechanism of cytochrome P450 for N-methylhydroxylation of nicotine: reaction pathways and regioselectivity of the enzymatic nicotine oxidation

The fundamental reaction mechanism of cytochrome P450 2A6 (CYP2A6)-catalyzed N-methylhydroxylation of (S)-(-)-nicotine and the free energy profile have been studied by performing pseudobond first-principles quantum mechanical/molecular mechanical (QM/MM) reaction-coordinate calculations. In the CYP2A6-(S)-(-)-nicotine binding structures that allow for 5'-hydroxylation, the N-methyl group is also sufficiently close to the oxygen of Cpd I for the N-methylhydroxylation reaction to occur. It has been demonstrated that the CYP2A6-catalyzed N-methylhydroxylation reaction is a concerted process involving a hydrogen-transfer transition state on both the quartet and the doublet states. The N-methylhydroxylation reaction proceeds mainly in the doublet state, since the free energy barriers on the doublet state are lower than the corresponding ones on the quartet state. The calculated free energy barriers indicate that (S)-(-)-nicotine oxidation catalyzed by CYP2A6 proceeds with a high regioselective abstraction of the hydrogen at the 5'-position, rather than the hydrogen at the N-methyl group. The predicted regioselectivity of 93% is in agreement with the most recent experimentally reported regioselectivity of 95%. The binding mode of (S)-(-)-nicotine in the active site of CYP2A6 is an important determinant for the stereoselectivity of nicotine (S)-(-)-oxidation, whereas the regioselectivity of (S)-(-)-nicotine oxidation is determined mainly by the free energy barrier difference between the 5'-hydroxylation and N-methylhydroxylation reactions.

Combined pharmacotherapy and behavioural interventions for smoking cessation

BACKGROUND

Both behavioural support (including brief advice and counselling) and pharmacotherapies (including nicotine replacement therapy (NRT), varenicline and bupropion) are effective in helping people to stop smoking. Combining both treatment approaches is recommended where possible, but the size of the treatment effect with different combinations and in different settings and populations is unclear.

OBJECTIVES

To assess the effect of combining behavioural support and medication to aid smoking cessation, compared to a minimal intervention or usual care, and to identify whether there are different effects depending on characteristics of the treatment setting, intervention, population treated, or take-up of treatment.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register in July 2012 for records with any mention of pharmacotherapy, including any type of NRT, bupropion, nortriptyline or varenicline.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials evaluating combinations of pharmacotherapy and behavioural support for smoking cessation, compared to a control receiving usual care or brief advice or less intensive behavioural support. We excluded trials recruiting only pregnant women, trials recruiting only adolescents, and trials with less than six months follow-up.

DATA COLLECTION AND ANALYSIS

Search results were prescreened by one author and inclusion or exclusion of potentially relevant trials was agreed by both authors. Data was extracted by one author and checked by the other.The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) and 95% confidence interval (CI) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

Forty-one studies with a total of more than 20,000 participants met the inclusion criteria. A large proportion of studies recruited people in healthcare settings or with specific health needs. Most studies provided NRT. Behavioural support was typically provided by specialists in cessation counselling, who offered between four and eight contact sessions. The planned maximum duration of contact was typically more than 30 minutes but less than 300 minutes. Overall, studies were at low or unclear risk of bias, and findings were not sensitive to the exclusion of any of the three studies rated at high risk of bias in one domain. One large study (the Lung Health Study) contributed heterogeneity due to a substantially larger treatment effect than seen in other studies (RR 3.88, 95% CI 3.35 to 4.50). Since this study used a particularly intensive intervention which included extended availability of nicotine gum, multiple group sessions and long term maintenance and recycling contacts, the results may not be comparable with the interventions used in other studies, and hence it was not pooled in other analyses. Based on the remaining 40 studies (15,021 participants) there was good evidence for a benefit of combination pharmacotherapy and behavioural treatment compared to usual care or brief advice or less intensive behavioural support (RR 1.82, 95% CI 1.66 to 2.00) with moderate statistical heterogeneity (I² = 40%). The pooled estimate for 31 trials that recruited participants in healthcare settings (RR 2.06, 95% CI 1.81 to 2.34) was higher than for eight trials with community-based recruitment (RR 1.53, 95% CI 1.33 to 1.76). Pooled estimates were lower in a subgroup of trials where the behavioural intervention was provided by specialist counsellors versus trials where counselling was linked to usual care (specialist: RR 1.73, 95% CI 1.55 to 1.93, 28 trials; usual provider: RR 2.41, 95% CI 1.91 to 3.02, 8 trials) but this was largely attributable to the small effect size in two trials using specialist counsellors where the take-up of the planned intervention was low, and one usual provider trial with alarge effect. There was little indirect evidence that the relative effect of an intervention differed according to whether participants in a trial were required to be motivated to make a quit attempt or not. There was only weak evidence that studies offering more sessions had larger effects and there was not clear evidence that increasing the duration of contact increased the effect, but there was more evidence of a dose-response relationship when analyses were limited to trials where the take-up of treatment was high.

AUTHORS' CONCLUSIONS

Interventions that combine pharmacotherapy and behavioural support increase smoking cessation success compared to a minimal intervention or usual care. Further trials would be unlikely to change this conclusion. We did not find strong evidence from indirect comparisons that offering more intensive behavioural support was associated with larger treatment effects but this could be because intensive interventions are less likely to be delivered in full.

Antisocial behavioral syndromes and 3-year quality-of-life outcomes in United States adults

OBJECTIVE

To examine 3-year quality-of-life (QOL) outcomes among United States adults with Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition (DSM-IV) antisocial personality disorder (ASPD), syndromal adult antisocial behavior without conduct disorder (CD) before age 15 [adulthood antisocial behavioral syndrome (AABS), not a DSM-IV diagnosis], or no antisocial behavioral syndrome at baseline.

METHOD

Face-to-face interviews (n = 34 653). Psychiatric disorders were assessed using the Alcohol Use Disorder and Associated Disabilities Interview Schedule - DSM-IV Version. Health-related QOL was assessed using the Short-Form 12-Item Health Survey, version 2 (SF-12v2). Other outcomes included past-year Perceived Stress Scale-4 (PSS-4) scores, employment, receipt of Supplemental Security Income (SSI), welfare, and food stamps, and participation in social relationships.

RESULTS

Antisocial personality disorder and AABS predicted poorer employment, financial dependency, social relationship, and physical health outcomes. Relationships of antisociality to SSI and food stamp receipt and physical health scales were modified by baseline age. Both antisocial syndromes predicted higher PSS-4, AABS predicted lower SF-12v2 Vitality, and ASPD predicted lower SF-12v2 Social Functioning scores in women.

CONCLUSION

Similar prediction of QOL by ASPD and AABS suggests limited utility of requiring CD before age 15 to diagnose ASPD. Findings underscore the need to improve prevention and treatment of antisocial syndromes.

Dronabinol for the treatment of cannabis dependence: a randomized, double-blind, placebo-controlled trial

Cannabis dependence is a substantial public health problem. Behavioral treatments have shown promise, but there are no effective medications for cannabis dependence. The purpose of this study was to evaluate the safety and efficacy of dronabinol, a synthetic form of delta-9-tetrahydrocannabinol, a naturally occurring pharmacologically active component of marijuana, in treating cannabis dependence. 156 cannabis-dependent adults were enrolled in a randomized, double-blind, placebo-controlled, 12-week trial. After a 1-week placebo lead-in phase, participants were randomized to receive dronabinol 20mg twice a day or placebo. Doses were maintained until the end of week 8 and then tapered off over 2 weeks. All participants received weekly motivational enhancement and relapse prevention therapy. Marijuana use was assessed using the timeline follow back method. There was no significant difference between treatment groups in the proportion of participants who achieved 2 weeks of abstinence at the end of the maintenance phase (dronabinol: 17.7%; placebo: 15.6%). Although both groups showed a reduction in marijuana use over time, there were no differences between the groups. Treatment retention was significantly higher at the end of the maintenance phase on dronabinol (77%), compared to placebo (61%) (P=.02), and withdrawal symptoms were significantly lower on dronabinol than placebo (P=.02). This is the first trial using an agonist substitution strategy for treatment of cannabis dependence. Dronabinol showed promise, it was well-tolerated, and improved treatment retention and withdrawal symptoms. Future trials might test higher doses, combinations of dronabinol with other medications with complementary mechanisms, or with more potent behavioral interventions.

Catalytic mechanism of cytochrome P450 for 5'-hydroxylation of nicotine: fundamental reaction pathways and stereoselectivity

A series of computational methods were used to study how cytochrome P450 2A6 (CYP2A6) interacts with (S)-(-)-nicotine, demonstrating that the dominant molecular species of (S)-(-)-nicotine in CYP2A6 active site exists in the free base state (with two conformations, SR(t) and SR(c)), despite the fact that the protonated state is dominant for the free ligand in solution. The computational results reveal that the dominant pathway of nicotine metabolism in CYP2A6 is through nicotine free base oxidation. Further, first-principles quantum mechanical/molecular mechanical free energy (QM/MM-FE) calculations were carried out to uncover the detailed reaction pathways for the CYP2A6-catalyzed nicotine 5'-hydroxylation reaction. In the determined CYP2A6-(S)-(-)-nicotine binding structures, the oxygen of Compound I (Cpd I) can abstract a hydrogen from either the trans-5'- or the cis-5'-position of (S)-(-)-nicotine. CYP2A6-catalyzed (S)-(-)-nicotine 5'-hydroxylation consists of two reaction steps, that is, the hydrogen transfer from the 5'-position of (S)-(-)-nicotine to the oxygen of Cpd I (the H-transfer step), followed by the recombination of the (S)-(-)-nicotine moiety with the iron-bound hydroxyl group to generate the 5'-hydroxynicotine product (the O-rebound step). The H-transfer step is rate-determining. The 5'-hydroxylation proceeds mainly with the stereoselective loss of the trans-5'-hydrogen, that is, the 5'-hydrogen trans to the pyridine ring. The calculated overall stereoselectivity of ∼97% favoring the trans-5'-hydroxylation is close to the observed stereoselectivity of 89-94%. This is the first time it has been demonstrated that a CYP substrate exists dominantly in one protonation state (cationic species) in solution, but uses its less-favorable protonation state (neutral free base) to perform the enzymatic reaction.

Fundamental reaction pathways for cytochrome P450-catalyzed 5'-hydroxylation and N-demethylation of nicotine

The reaction pathways for 5'-hydroxylation and N-demethylation of nicotine catalyzed by cytochrome P450 were investigated by performing a series of first-principle electronic structure calculations on a catalytic reaction model system. The computational results indicate that 5'-hydroxylation of nicotine occurs through a two-state stepwise process, that is, an initial hydrogen atom transfer from nicotine to Cpd I (i.e., the HAT step) followed by a recombination of the nicotine moiety with the iron-bound hydroxyl group (i.e., the rebound step) on both the high-spin (HS) quartet and low-spin (LS) doublet states. The HAT step is the rate-determining one. This finding represents the first case that exhibits genuine rebound transition state species on both the HS and the LS states for C(alpha)-H hydroxylation of amines. N-Demethylation of nicotine involves a N-methylhydroxylation to form N-(hydroxymethyl)nornicotine, followed by N-(hydroxymethyl)nornicotine decomposition to nornicotine and formaldehyde. The N-methylhydroxylation step is similar to 5'-hydroxylation, namely, a rate-determining HAT step followed by a rebound step. The decomposition process occurs on the deprotonated state of N-(hydroxymethyl)nornicotine assisted by a water molecule, and the energy barrier is significantly lower than that of the N-methylhydroxylation process. Comparison of the rate-determining free energy barriers for the two reaction pathways predicts a preponderance of 5'-hydroxylation over the N-demethylation by roughly a factor of 18:1, which is in excellent agreement with the factor of 19:1 derived from available experimental data.

Effects of treatment for tobacco dependence on resting cerebral glucose metabolism

While bupropion HCl and practical group counseling (PGC) are commonly used treatments for tobacco dependence, the effects of these treatments on brain function are not well established. For this study, 54 tobacco-dependent cigarette smokers underwent resting (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning before and after 8 weeks of treatment with bupropion HCl, PGC, or pill placebo. Using Statistical Parametric Mapping (SPM 2), changes in cerebral glucose metabolism from before to after treatment were compared between treatment groups and correlations were determined between amount of daily cigarette usage and cerebral glucose metabolism. Compared with placebo, the two active treatments (bupropion HCl and PGC) had reductions in glucose metabolism in the posterior cingulate gyrus. Further analysis suggested that PGC had a greater effect than bupropion HCl on glucose metabolism in this region. We also found positive correlations between daily cigarette use and glucose metabolism in the left occipital gyrus and parietal-temporal junction. There were no significant negative correlations between daily cigarette use and glucose metabolism. Our findings suggest that bupropion HCl and PGC reduce neural activity much as the performance of a goal-oriented task does in the default mode network of the brain, including the posterior cingulate gyrus. Thus, this study supports the theory that active treatments for tobacco dependence move the brain into a more goal-oriented state.

Smoking cessation for persons living with HIV: a review of currently available interventions

Smoking among persons living with HIV infection (PLWH) is estimated to be two to three times greater than the general population. Data suggest that cigarette smoking is more common among PLWH because of factors such as lower socioeconomic status, previous or concurrent illicit drug and alcohol use, age, education level, and concurrent depressive symptoms. Cigarette smoking in HIV-infected individuals has been associated with higher risk of certain cancers, infections, and a decrease in response to antiretroviral therapy. Recent guidelines from the U.S. Public Health Service have recommended the use of counseling and pharmacologic therapies for all patients interested in quitting smoking. It is critical for clinicians caring for PLWH to be familiar with these modalities. This article provides an overview of currently available interventions for smoking cessation, reviews considerations for patients with HIV, and discusses clinical implications for nurses and advanced practice clinicians.