Is clonidine an effective smoking cessation therapy?

[Perioperative smoking cessation (conventional smoking and e-cigarettes) in 2023. A narrative review of the literature]

INTRODUCTION

Tobacco addiction is the leading cause of preventable death. During the perioperative period, patients who smoke are at increased risk of systemic as well as surgical site complications.

STATE OF THE ART

Surgery is an ideal time for change of lifestyle habits. It is vital to seize this opportunity to improve the patient's health in the long- as well as the short-term. Smoking cessation should be encouraged in all surgical patients. Initiating smoking cessation combines pharmacological treatment and a behavioral approach. In this field, significant advances have been recorded over the last decade. This review proposes a practical approach that every practitioner will be able to apply.

PERSPECTIVES

In this review, we will also examine ongoing research, particularly as regards vaccination and the place of biomarkers.

CONCLUSIONS

Smoking represents a major source of health-related complications. Smoking cessation must therefore remain a priority in the management of medical and surgical patients.

Absorption of Clonidine from a Halved Transdermal System — A Pilot Study

Objective:

To assess whether clonidine bioavailability is compromised when a transdermal system is cut in half.

Methods:

Seven healthy volunteers were enrolled in this prospective crossover study. In phase I, an intact clonidine 0.1 mg/24 h transdermal system (TS-1) was applied and plasma clonidine concentration was obtained 72 hours after application, after steady-state (48–72 hours) was purported to have been reached. After a minimum seven-day washout period, half of a clonidine 0.2 mg/24 h transdermal system (½TS-2) was applied in phase II, with plasma clonidine concentrations obtained at 24, 48, 72, 120, and 192 hours following application.

Results:

Mean plasma clonidine concentrations at 72 hours with TS-1 in phase I were 0.17 ± 0.07 ng/mL. Mean plasma clonidine concentrations at 24, 48, 72, 120, and 192 hours with ½TS-2 in phase II were 0.16 ± 0.11, 0.15 ± 0.06, 0.15 ± 0.05, 0.19 ± 0.4, and 0.20 ± 0.8 ng/mL, respectively. There was no statistically significant difference between mean concentrations at 72 hours in phases I and II, but individual clonidine concentrations between phases varied 50–286%. Individual concentration versus time curves obtained from subjects in phase II lacked a consistent pattern.

Conclusions:

Although there was no statistically significant difference in mean concentrations at 72 hours, individual clonidine concentration variations may have a clinically significant impact. The lack of a consistent plasma concentration versus time pattern may also be of clinical concern. Based on these results, cutting the clonidine transdermal system may compromise its integrity, and is therefore not recommended.

The Past, Present, and Future of Nicotine Addiction Therapy

The tobacco addiction treatment field is progressing through innovations in medication development, a focus on precision medicine, and application of new technologies for delivering support in real time and over time. This article reviews the evidence for combined and extended cessation pharmacotherapy and behavioral strategies including provider advice, individual counseling, group programs, the national quitline, websites and social media, and incentives. Healthcare policies are changing to offer cessation treatment to the broad population of smokers. With knowledge of the past and present, this review anticipates what is likely on the horizon in the clinical and public health effort to address tobacco addiction.

Current and emerging pharmacotherapeutic options for smoking cessation

Tobacco smoking remains the single most preventable cause of morbidity and mortality in developed countries and poses a significant threat across developing countries where tobacco use prevalence is increasing. Nicotine dependence is a chronic disease often requiring multiple attempts to quit; repeated interventions with pharmacotherapeutic aids have become more popular as part of cessation therapies. First-line medications of known efficacy in the general population include varenicline tartrate, bupropion hydrochloride, nicotine replacement therapy products, or a combination thereof. However, less is known about the use of these products in marginalized groups such as the indigenous, those with mental illnesses, youth, and pregnant or breastfeeding women. Despite the efficacy and safety of these first line pharmacotherapies, many smokers continue to relapse and alternative pharmacotherapies and cessation options are required. Thus, the aim of this review is to summarize the existing and developing pharmacotherapeutic and other options for smoking cessation, to identify gaps in current clinical practice, and to provide recommendations for future evaluations and research.

[Pharmacotherapeutic treatment strategies for smoking cessation]

Regular tobacco smoking occurs in about 35% of the male and 25% of the female German population. Individual attempts to independently quit smoking and to remain abstinent for 1 year have been shown to be successful in less than 5% of cases. This rate can be doubled by means of individual consulting and cognitive-behavioral interventions and additional pharmacological treatment might increase abstinence rates up to 25%. Apart from nicotine substitution (e.g. transdermal, oral and inhalative applications) and bupropion, recent studies have shown beneficial effects of varenicline for smoking cessation and abstinence. Varenicline, a selective partial nicotinergic agonist, has been specifically developed for the purpose of smoking cessation. Currently available data suggest that varenicline is more effective compared to nicotine substitution therapy and bupropion, increasing the abstinence likelihood by a factor of 2.3 compared to a placebo. Recent data regarding anti-nicotine vaccines suggest that this approach might yield a comparable treatment outcome and probably even better relapse-preventing effects than conventional psychopharmacological strategies. The first anti-nicotine vaccines are expected to be approved by national authorities within the forthcoming 1-2 years.

Targeting nicotine addiction: the possibility of a therapeutic vaccine

Cigarette smoking is the primary cause of lung cancer, cardiovascular diseases, reproductive disorders, and delayed wound healing all over the world. The goals of smoking cessation are both to reduce health risks and to improve quality of life. The development of novel and more effective medications for smoking cessation is crucial in the treatment of nicotine dependence. Currently, first-line smoking cessation therapies include nicotine replacement products and bupropion. The partial nicotinic receptor agonist, varenicline, has recently been approved by the US Food and Drug Administration (FDA) for smoking cessation. Clonidine and nortriptyline have demonstrated some efficacy, but side effects may limit their use to second-line treatment products. Other therapeutic drugs that are under development include rimonabant, mecamylamine, monoamine oxidase inhibitors, and dopamine D3 receptor antagonists. Nicotine vaccines are among newer products seeking approval from the FDA. Antidrug vaccines are irreversible, provide protection over years and need booster injections far beyond the critical phase of acute withdrawal symptoms. Interacting with the drug in the blood rather than with a receptor in the brain, the vaccines are free of side effects due to central interaction. For drugs like nicotine, which interacts with different types of receptors in many organs, this is a further advantage. Three anti-nicotine vaccines are today in an advanced stage of clinical evaluation. Results show that the efficiency of the vaccines is directly related to the antibody levels, a fact which will help to optimize the vaccine effect. The vaccines are expected to appear on the market between 2011 and 2012.

Treatment of nicotine addiction: present therapeutic options and pipeline developments

Tobacco use is a global pandemic that poses a substantial and costly health burden. There are some treatment options are available, but currently marketed smoking-cessation drugs lack high levels of efficacy, particularly in real-life settings. Consequently, there is a compelling need for more effective pharmacotherapies to aid smokers in maintaining long-term abstinence. Advances in the understanding of the mechanisms involved in nicotine dependence have recently been translated into new medications and vaccines that interfere with nicotine signaling, many of which are currently at an advanced stage of development. In the present article we review current and emerging pharmacotherapies for tobacco dependence, focusing on the mechanistic rationale for their potential anti-addiction efficacy, major findings in preclinical and clinical studies, and future research directions.

Biological basis of tobacco addiction: Implications for smoking-cessation treatment

Tobacco use became common all over the world after discovery of Americas. Tobacco, a plant carries in its leaves an alkaloid called nicotine, which is responsible not only for several pathophysiological changes in the body but also develops tolerance to its own action with repeated use. Studies suggest that the alpha-4 beta-2 nicotine acetylcholine receptor subtype is the main receptor that mediates nicotine dependence. Nicotine acts on these receptors to facilitate neurotransmitter release (dopamine and others), producing pleasure and mood modulation. Repeated exposure to nicotine develops neuroadaptation of the receptors, resulting in tolerance to many of the effects of nicotine. Withdrawal symptoms appear on stoppage of tobacco use, which are characterized by irritability, anxiety, increased eating, dysphoria, and hedonic dysregulation, among others. Smoking is also reinforced by conditioning. Pharmacotherapies for smoking cessation should reduce withdrawal symptoms and block the reinforcing effects of nicotine obtained from smoking without causing excessive adverse effects.

Pharmacotherapy of addictive disorders

Substance use disorders are highly prevalent in the United States and cause considerable damage to our society. They are underrecognized and undertreated despite a vast body of literature demonstrating the efficacy of treatment using both psychosocial and psychopharmacological modalities. For the last decade, research and progress into the biological basis of the addictive process has led to a rapidly growing number of pharmacological agents used to interrupt the addictive process at its various stages such as the initiation of substance abuse, the transition from abuse to dependence, and the prevention of drug reinstatement or relapse. Food and Drug Administration-approved medications exist for nicotine, alcohol, and opioid use disorders, and progress is being made to develop agents for stimulant use disorders. Regarding nicotine use disorders, nicotine replacement therapies,bupropion and varenicline, have Food and Drug Administration approval, and future options exist with endocannabinoid antagonists and immune therapy. Aversive agents, opiate antagonists, and glutamate based interventions are currently approved to treat alcohol use disorders with future promise with GABAergic, serotonergic, and endocannabinoid system agents. Opiate addiction is treated by approved agonist and antagonist mu-opioid medications with the future potential for agents that can modulate the stress systems and the iboga alkaloids. Although no pharmacotherapies are currently approved for cocaine addiction, promising lines of research include agents that affect dopaminergic, GABAergic, serotonergic,and glutamatergic systems as well as the promise for immune therapies.

Therapeutic advances in the treatment of nicotine addiction: present and future

While the proportion of the adult population that smokes has declined steadily in several westernized societies, the rate of successful quit attempts is still low. This is because smokers develop nicotine dependence, a powerful addiction that may require multiple attempts and long-term treatment to achieve enduring abstinence. Currently available first-line agents for smoking cessation therapy include nicotine replacement therapy (available in several formulations, including transdermal patch, gum, nasal spray, inhaler, and lozenge), bupropion (an atypical antidepressant), and varenicline (a partial agonist of the α4β2 nicotinic acetylcholine receptor that was recently developed and approved specifically for smoking cessation therapy). Second-line agents are nortriptyline (a tricyclic antidepressant agent) and the antihypertensive agent clonidine. With the exception of varenicline, which has been shown to offer significant improvement in abstinence rates over bupropion, all of the available treatments appear similarly effective. The adverse event profiles of nortriptyline and clonidine make them more appropriate for second-line therapy, when first-line treatments have failed or are not tolerated. However, the currently marketed smoking cessation drugs reportedly lack high levels of efficacy, particularly in real-life settings. New medications and vaccines with significant clinical advantage are now in the advanced stage of development and offer promise. These include nicotine vaccines and monoamine type B inhibitors. In this review article we discuss current and emerging pharmacotherapies for tobacco dependence focusing on their mechanisms of action, efficacy and adverse event profiles.

Treatment of tobacco dependence in mental health and addictive disorders

People with mental health and addictive (MHA) disorders smoke at high rates and require tobacco treatment as a part of their comprehensive psychiatric care. Psychiatric care providers often do not address tobacco use among people with mental illness, possibly owing to the belief that their patients will not be able to quit successfully or that even short-term abstinence will adversely influence psychiatric status. Progress in the development of treatments has been slow in part because smokers with current MHA disorders have been excluded from most smoking cessation trials. There are several smoking cessation treatment options, including psychological and pharmacological interventions, that should be offered to people with an MHA disorder who smoke. Building motivation and readiness to quit smoking is a major challenge, and therefore motivational interventions are essential. We review the treatment options for people with tobacco dependence and MHA disorders, offer recommendations on tobacco assessment and tailored treatment strategies, and provide suggestions for future research. Treatment efficacy could be enhanced through promoting smoking reduction as an initial treatment goal, extending duration of treatment, and delivering it within an integrated care model that also aims to reduce the availability of tobacco in MHA treatment settings and in the community.

Neurobiology of nicotine addiction: implications for smoking cessation treatment

Nicotine sustains addictive tobacco use, which in turn causes much premature disability and death. The essence of drug addiction is loss of control of drug use. Molecular biology studies suggest that the alpha(4)beta(2) nicotinic acetylcholine receptor subtype is the main receptor mediating nicotine dependence. Nicotine acts on these brain nicotinic cholinergic receptors to facilitate neurotransmitter release (dopamine and others), producing pleasure, stimulation, and mood modulation. Neuroadaptation develops with repeated exposure to nicotine, resulting in tolerance to many of the effects of nicotine. When a smoker stops smoking, a nicotine withdrawal syndrome ensues, characterized by irritability, anxiety, increased eating, dysphoria, and hedonic dysregulation, among other symptoms. Smoking is also reinforced by conditioning, such that specific stimuli that are psychologically associated with smoking become cues for an urge to smoke. These include the taste and smell of tobacco, as well as particular moods, situations, and environmental cues. Pharmacotherapies to aid smoking cessation should ideally reduce nicotine withdrawal symptoms and block the reinforcing effects of nicotine obtained from smoking without causing excessive adverse effects. Further, given the important role of sensory effects of smoking and psychoactive effects of nicotine, counseling and behavioral therapies are important adjuncts to and substantially augment the benefits of pharmacotherapy.

Update on pharmacologic options for smoking cessation treatment

Although the proportion of the adult population in the United States that smokes has decreased steadily, the rate of successful quit attempts is still low. Smokers develop nicotine dependence that resembles other addictions, and may require multiple attempts and long-term treatment to sustain abstinence. Currently available first-line agents for smoking cessation therapy include nicotine replacement therapy, which is available in several formulations, including transdermal patch, gum, nasal spray, inhaler, and lozenge; bupropion, an atypical antidepressant; and varenicline, a partial agonist of the alpha(4)beta(2) nicotinic acetylcholine receptor that was recently developed and approved specifically for smoking cessation therapy. Second-line agents are nortriptyline, a tricyclic antidepressant agent, and clonidine, an antihypertensive drug. With the exception of varenicline, which has been shown to offer significant improvement in abstinence rates over bupropion, all of the available treatments appear similarly effective. However, the adverse event profiles of nortriptyline and clonidine make them more appropriate for second-line therapy, when first-line treatments have failed or are not tolerated. Rimonabant, a cannabinoid-1 receptor antagonist that was being developed for smoking cessation, received a nonapprovable letter from the FDA in 2006 and there is no further information as to whether development for this indication is continuing for this agent. Nicotine vaccines are under investigation and offer promise, especially for relapse prevention. Ultimately, selection of pharmacologic agent should be based on the patient's comorbidities and preferences, as well as on the agent's adverse event profile.

Trends in cigarette smoking initiation and cessation among birth cohorts of 1926-1970 in Germany

This study examines temporal differences in cigarette smoking initiation and cessation among male and female birth cohorts of 1926-1970 born in Germany. Based on the German Federal Health Survey 1998 the sample is divided into a series of 5-year sex-birth cohorts, beginning with those born between 1926 and 1930 and extending to those born between 1966 and 1970. The final data file consists of a sample of 5110 people. Ever-smoking prevalence among men varies from 60 to 70% between the birth cohorts, while in women born 1926-1930 ever-smoking increases from 20 to about 50% in those born 1966-1970. A reduction of the median age at starting smoking also takes place between the cohorts. With 8.5 years this decrease is more incisive among women, compared with a drop of 2 years among men. Regarding cessation patterns the analysis shows a shift towards a shorter duration of smoking with succeeding birth cohorts, again this shift is more incisive in women. But even in the youngest cohort still more than 50% of ever-smokers smoke regularly for more than 25 years. In Germany tobacco-control activities are required in order to take antismoking actions that especially prevent youth from starting to smoke and that support smokers in quitting.

Novel pharmacotherapeutic targets for the management of drug addiction

Despite individual variation in the liability to the abuse of psychoactive substances, there is substantial commonality shared by drugs of abuse. The knowledge of these common mechanisms together with the continued elucidation of the neurobiological underpinnings of withdrawal symptoms, drug intake, craving, relapse, and co-morbid psychiatric associations are critically important for the development of new therapeutic strategies. The present review will focus on recent advances in the development of innovative pharmacotherapeutic agents, which should promote higher efficacy (abstinence, prevention of relapse, long-term recovery) and patient compliance, as well as improved safety profiles.

Combination treatment for nicotine dependence: state of the science

Both nicotine replacement and sustained-release buproprion double the odds of achieving short- and moderate-term abstinence from nicotine. However, questions remain about the efficacy of combining pharmacotherapies. Our purposes were to review the evidence for (1) combined pharmacotherapy and (2) multimodal treatment combining pharmacotherapy and behavioral treatment and to recommend combinations of treatments to reduce nicotine dependence. Combining first-line pharmacotherapies with each other or with investigational drugs shows little benefit. In contrast, trials combining specific behavioral treatments with first-line pharmacotherapies show enhanced smoking cessation rates, but benefits are not seen in all populations. We recommend future directions for research, including better specification of behavioral components and further examination of the length and timing of treatment.

Pharmacotherapy of tobacco dependence

Smoking cessation activities and support for its implementation should be integrated into the health care system. The outcome of smoking cessation has improved with the availability of proper behavior approaches and medications. Incorporating these guidelines into daily clinical practice ensures that health care providers provide the opportunity for patients to quit smoking. The best hope of improved treatment comes from combining existing and new pharmacotherapies with effective behavioral therapy.

Pharmacologic treatment of chronic obstructive pulmonary disease: past, present, and future

Pharmacologic treatment of chronic obstructive pulmonary disease (COPD) has evolved considerably during the past several decades. Initial treatment of the disease was accomplished primarily through antibiotics, mucolytic agents, and nonselective sympathomimetic agents. Up-to-date treatment guidelines stratified according to strength of evidence are published in the National Heart, Lung, and Blood Institute-World Health Organization workshop report on the Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease. Current drug therapy for stable COPD focuses primarily on bronchodilation through inhaled beta2-agonists and anticholinergic agents, immunization, and elimination of smoking as a risk factor. Although many pharmacologic agents are available to treat COPD, no drug has demonstrated effectiveness in halting progression of the disease. Rather, the goal of drug therapy at this time is to maintain control of symptoms and prevent COPD exacerbations. Compared with asthma, research into treatment for COPD has been minimal. However, a long-acting anticholinergic agent, tiotropium, has received approval status by the United States Food and Drug Administration. The drug has been shown to improve spirometric parameters, quality of life, and utilization of health care resources. In addition, several new targets for the treatment of COPD are being studied, and a few agents, including some that theoretically may slow functional decline in patients with COPD, are in development.

Current pharmacological treatments for nicotine dependence

There are nearly 1.1 billion users of nicotine and tobacco products worldwide. Tobacco use through cigarette smoking is the leading preventable cause of death in the world and kills nearly four million people annually. However, although some cigarette smokers are able to quit, many are not, and standard medications to assist in smoking cessation (e.g. nicotine-replacement therapies and sustained-release bupropion) are ineffective in many remaining smokers. Recent developments in our understanding of the neurobiology of nicotine dependence have identified several neurotransmitter systems that might contribute to the process of smoking maintenance and relapse, including dopamine, noradrenaline, 5-hydroxytryptamine, acetylcholine, endogenous opioids, GABA, glutamate and endocannabinoids. Several existing medications are being tested as treatments for nicotine dependence and novel investigational agents are under development as effective treatments for nicotine dependence in the 'hard to treat' tobacco user.

Clonidine for smoking cessation

BACKGROUND

Clonidine was originally used to lower blood pressure. It acts on the central nervous system and may reduce withdrawal symptoms in various addictive behaviours, including tobacco use.

OBJECTIVES

The aim of this review is to determine clonidine's effectiveness in helping smokers to quit.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register for trials of clonidine. Date of the most recent search: May 2004.

SELECTION CRITERIA

We considered randomized trials of clonidine versus placebo with a smoking cessation endpoint assessed at least 12 weeks following the end of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of subjects, the dose and duration of clonidine therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least 12 weeks follow up in patients smoking at baseline. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effect model.

MAIN RESULTS

Six trials met the inclusion criteria. There were three trials of oral, and three of transdermal clonidine. Some form of behavioural counselling was offered to all participants in five of the six trials. There was a statistically significant effect of clonidine in one of these trials. The pooled odds ratio for success with clonidine versus placebo was 1.89 (95% confidence interval 1.30 to 2.74). There was a high incidence of dose-dependent side-effects, particularly dry mouth and sedation.

REVIEWERS' CONCLUSIONS

Based on a small number of trials, in which there are potential sources of bias, clonidine is effective in promoting smoking cessation. Prominent side-effects limit the usefulness of clonidine for smoking cessation.

Neuropsychiatric effects of cardiovascular drug therapy

Various cardiovascular drugs have been shown to have neuropsychiatric effects that can be harmful or therapeutically beneficial to patients. As an example, both sedation and mental depression have been described in patients receiving centrally acting antihypertensive drugs and beta-adrenergic blockers, related to their antiadrenergic actions. In contrast, because of these antiadrenergic actions, agents like clonidine have been used to treat opiate, alcohol, and nicotine withdrawal, while beta blockers have been used to treat symptoms of performance anxiety, migraine, and psychocardiac disorders. Some antiarrhythmic drugs have been associated with delirium, and digitalis toxicity has been shown to cause hallucinations, mania, euphoria, and depression. The calcium-channel blocker verapamil has been used as an adjunctive treatment in patients with bipolar disorders. Since neuropsychiatric symptoms are seen in patients with cardiovascular disease, clinicians should be aware of the possible relationship between these symptoms and concurrent cardiovascular drug therapy.

Smoking cessation in women. Special considerations

Women may be at relatively greater risk of smoking-related diseases than men but tend to have less success than men in quitting smoking. The failure of most outcome studies to report results by gender and the lack of statistical power for detecting significant gender differences currently do not allow for many firm conclusions to be drawn about smoking cessation rates in women, but several trends warrant attention and further study. First, the difference in cessation rates for women versus men may be even greater in trials of nicotine replacement therapies (NRT). This suggests that women benefit less from NRT relative to men, although this difference may depend on the particular form of NRT (e.g. inhaler versus gum). On the other hand, some non-NRT medications may reverse the poorer outcome of women, producing quit rates in women comparable with those in men. Gender differences in outcome, as well as overall success rates, with NRT and some of the non-NRT medications appear to be enhanced when treatment includes substantial behavioural counselling. However, while several of the non-NRT medications may be particularly appropriate to consider for treating women trying to quit smoking, adverse effects may limit widespread use of some of these drugs, such as clonidine and naltrexone. Thus, even if the gender differences in outcome with NRT versus non-NRT drugs are confirmed in further research, such findings do not necessarily justify limiting NRT use in women, because such treatment is clearly effective and is likely to be safer and more readily available than non-NRT medications. Nevertheless, study of the mechanisms by which some non-NRT drugs are effective in women may aid our understanding of factors that are more influential in smoking behaviour in women than in men. Secondly, smoking cessation treatment for women must address several other issues that often emerge, and these are most likely to require behavioural counselling that is tailored to these problems. These issues include concern about bodyweight gain, restrictions on medication use in pregnant smokers, variability in mood and withdrawal as a function of menstrual cycle phase, harnessing social support to foster abstinence, and the possibility that smoking-associated environmental cues may be more influential in smoking behaviour in women than men. Greater attention to gender differences in clinical trial outcomes and to addressing concerns of women smokers may aid in the development of substantially improved smoking cessation interventions for women.

Effect of nonnicotine pharmacotherapy on smoking behavior

Smoking-related disease is the single biggest preventable cause of morbidity and mortality in the United States, yet approximately 25% of Americans continue to smoke. Various dosage forms of nicotine replacement therapy increase smoking quit rates relative to placebo, but they generally do not result in 1-year quit rates of over 20%. To increase these rates, a number of nonnicotine agents have been investigated. Drugs that modulate noradrenergic neurotransmission (bupropion, nortriptyline, moclobemide) are more effective than those affecting serotonin (selective serotonin reuptake inhibitors, buspirone, ondansetron) or other neurotransmitters.

Consenso sobre o tratamento da dependência de nicotina

Têm sido atribuídas à dependência de nicotina 20% das mortes nos EUA. Estudos têm mostrado que 30% a 50% das pessoas que começam a fumar escalam para um uso problemático. Nos últimos 20 anos, a educação e a persuasão não foram suficientes para promover uma mudança política, cultural e social relacionada ao comportamento de fumar. As intervenções para interromper o uso de tabaco ainda não estão integradas às rotinas dos serviços de saúde no mundo. A falta de estratégias de integração, de tempo disponível para acoplar ações assistenciais mais específicas e mesmo a percepção dos profissionais de saúde de que os tratamentos para a dependência de nicotina são pouco efetivos são algumas das barreiras apontadas. Assim, elaborar um consenso sobre a dependência de nicotina teve como objetivos: • levantar dados epidemiológicos relevantes relacionados ao uso do tabaco no mundo e no Brasil; • revisar as ações gerais e centrais da nicotina; • elaborar um protocolo de triagem mínimo para serviços de atenção primária à saúde; • recomendar diretrizes básicas de avaliação, diagnóstico e tratamento para todos os níveis de atenção à saúde em relação à dependência de nicotina; • fornecer sugestões para a abordagem de grupos especiais de pacientes: adolescentes, gestantes, idosos, pacientes em regime de internação, obesos e pacientes com comorbidades psiquiátricas, cardiovasculares e respiratórias.

Advances in non-nicotine pharmacotherapy for smoking cessation

Progress in understanding the pharmacological nature of tobacco addiction, along with the modest success rates achieved by the nicotine replacement therapies, has provided the major impetus for the development of non-nicotine drugs as smoking cessation aids. This article reviews evidence from controlled trials of several non-nicotine medications for the treatment of nicotine dependence. Clonidine was the first non-nicotine medication to show efficacy for smoking cessation in multiple studies, but its effect was found to be limited at best. Positive results across several trials have been consistently demonstrated for amfebutamone (bupropion). Encouraging results have also been observed for nortriptyline and moclobemide. Studies of combined treatments using non-nicotine medications (amfebutamone, mecamylamine, oral dextrose) with nicotine replacement therapy suggest increased efficacy relative to treatments using one or the other treatment strategy alone. Thus, available evidence indicates that non-nicotine drug treatments offer a promising panoply of therapeutic strategies for the addicted smoker.

Clonidine for smoking cessation

BACKGROUND

Clonidine was originally used to lower blood pressure. It acts on the central nervous system and may reduce withdrawal symptoms in various addictive behaviours, including tobacco use.

OBJECTIVES

The aim of this review is to determine clonidine's effectiveness in helping smokers to quit.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register. Date of the most recent search: October 1998.

SELECTION CRITERIA

We considered randomised trials of clonidine versus placebo with a smoking cessation endpoint assessed at least 12 weeks following the end of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of subjects, the dose and duration of clonidine therapy, the outcome measures, method of randomisation, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least twelve weeks follow-up in patients smoking at baseline. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effects model.

MAIN RESULTS

Six trials met the inclusion criteria. There were three trials of oral, and three of transdermal clonidine. Some form of behavioural counselling was offered to all participants in five of the six trials. There was a statistically significant effect of clonidine in one of these trials. The pooled odds ratio for success with clonidine vs placebo was 1.89 (95% confidence interval 1.30 to 2.74). There was a high incidence of dose-dependent side-effects, particularly dry mouth and sedation.

REVIEWER'S CONCLUSIONS

Based on a small number of trials, in which there are potential sources of bias, clonidine is effective in promoting smoking cessation. Prominent side-effects limit the usefulness of clonidine for smoking cessation.

Non-nicotine pharmacotherapy for smoking cessation

The selection of a non-nicotine treatment is based on the acceptability of various treatments with smokers, the ability to address the specific neurobiology of nicotine addiction, and the option to provide treatment for co-morbid conditions of nicotine-dependent patients. The search for effective treatments for nicotine dependence has generated a wide variety of non-nicotine approaches based on the neuropharmacologic and sensory basis for tobacco use. The only non-nicotine, FDA-approved medication is bupropion, an amino-ketone agent that is believed to work on the dopaminergic and noradrenergic neurotransmitters involved in perpetuating nicotine dependence. This article reviews other unapproved medications, mechanisms of action, and their effectiveness in clinical trials.

Clonidine poisoning in Jefferson County, Alabama

STUDY OBJECTIVE

To describe the epidemiology of clonidine-related hospitalization in children, to evaluate the efficacy of naloxone, and to review the clinical effects of clonidine toxicity.

METHODS

This was a retrospective analysis in an urban teaching pediatric emergency department with an annual census of 55,000 involving 80 children younger than 6 years who were admitted for clonidine ingestion during a 6-year period.

RESULTS

Clonidine commonly belonged to the patient's grand-mother (54%). Black children were twice as likely to be hospitalized for clonidine ingestion than white children compared with children hospitalized for any injury. Average time to onset of symptoms was 35 minutes. Decreased level of consciousness was the most common presenting symptom (96%). Mean ED vital signs were systolic blood pressure, 102 mm Hg; pulse, 98; respirations, 25 (six patients intubated); and temperature, 36.6 degrees C, Naloxone was administered to 49% of patients, 84% of whom demonstrated no response.

CONCLUSION

Clonidine ingestion is endemic in our area. Serious clinical effects mandate that all children with clonidine ingestion be triaged to a health care facility. Naloxone as an antidote for clonidine remains controversial.

The future of smoking cessation therapy in the United States

Six trends that are likely to influence the future content, format, delivery and reach of smoking cessation therapy in the United States are discussed: (1) changing characteristics of smokers (e.g. more likely to be poor, have psychiatric co-morbidity and be more nicotine dependent), (2) health care reform demands for cost-effectiveness, (3) development of guidelines/algorithms that recommend stepped-care approaches, (4) continued emphasis on smoking as a form of drug dependence requiring intensive pharmacological and behavior therapy for some smokers, (5) interest in harm-reduction strategies for smokers unable or unwilling to quit (and 6) smoking cessation therapies become reimbursable on par with other drug dependencies.

The benefits of stopping smoking and the role of nicotine replacement therapy in older patients

Considerable benefits accrue from stopping smoking in older patients. Reversal of the short term cardiovascular adverse effects of smoking is rapid. Long term risk reduction appears to occur as a result of decreased life-time exposure to tobacco smoke. The pharmacology of nicotine has not been studied in older patients but is unlikely to change in clinically important ways with advancing age. Nicotine replacement doubles long term success rates, compared with placebo, among younger smokers of > or = cigarettes per day. There is no reason to believe its efficacy should be less among older smokers. Transdermal nicotine is the replacement therapy of choice in older patients because of once-daily administration and good tolerability. Approximately half of the users of transdermal nicotine smoke concurrently with treatment. It is unlikely that concurrent smoking or high doses of nicotine replacement therapy will adversely effect healthy patients. While it is generally believed that patients with unstable coronary heart disease may be at risk from concurrent smoking during nicotine replacement therapy, it is unclear whether this risk is greater than the risk of smoking alone. Nicotine replacement therapy is a logical approach for motivated, older smokers who are unable to stop smoking by simpler means. Results can be augmented by including other interventions, such as counselling and follow-up support.