Smoking Cessation Pharmacotherapy?Nicotine and Non-Nicotine Preparations

A mechanistic overview of approaches for the treatment of psychostimulant dependence

Psychostimulant use disorder is a major health issue around the world with enormous individual, family-related and societal consequences, yet there are no effective pharmacological treatments available. In this review, a target-based overview of pharmacological treatments toward psychostimulant addiction will be presented. We will go through therapeutic approaches targeting different aspects of psychostimulant addiction with focus on three major areas; 1) drugs targeting signalling, and metabolism of the dopamine system, 2) drugs targeting either AMPA receptors or metabotropic glutamate receptors of the glutamate system and 3) drugs targeting the severe side-effects of quitting long-term psychostimulant use. For each of these major modes of intervention, findings from pre-clinical studies in rodents to clinical trials in humans will be listed, and future perspectives of the different treatment strategies as well as their potential side-effects will be discussed. Pharmaceuticals modulating the dopamine system, such as antipsychotics, DAT-inhibitors, and disulfiram, have shown some promising results. Cognitive enhancers have been found to increase aspects of behavioural control, and drugs targeting the glutamate system such as modulators of metabotropic glutamate receptors and AMPA receptors have provided interesting changes in relapse behaviour. Furthermore, CRF-antagonists directed toward alleviating the symptoms of the withdrawal stage have been examined with interesting resulting changes in behaviour. There are promising results investigating therapeutics for psychostimulant addiction, but further preclinical work and additional human studies with a more stratified patient selection are needed to prove sufficient evidence of efficacy and tolerability.

Reduced cue-induced reinstatement of cocaine-seeking behavior in Plcb1 +/- mice

Cocaine addiction causes serious health problems, and no effective treatment is available yet. We previously identified a genetic risk variant for cocaine addiction in the PLCB1 gene and found this gene upregulated in postmortem brains of cocaine abusers and in human dopaminergic neuron-like cells after an acute cocaine exposure. Here, we functionally tested the contribution of the PLCB1 gene to cocaine addictive properties using Plcb1+/- mice. First, we performed a general phenotypic characterization and found that Plcb1+/- mice showed normal behavior, although they had increased anxiety and impaired short-term memory. Subsequently, mice were trained for operant conditioning, self-administered cocaine for 10 days, and were tested for cocaine motivation. After extinction, we found a reduction in the cue-induced reinstatement of cocaine-seeking behavior in Plcb1+/- mice. After reinstatement, we identified transcriptomic alterations in the medial prefrontal cortex of Plcb1+/- mice, mostly related to pathways relevant to addiction like the dopaminergic synapse and long-term potentiation. To conclude, we found that heterozygous deletion of the Plcb1 gene decreases cue-induced reinstatement of cocaine-seeking, pointing at PLCB1 as a possible therapeutic target for preventing relapse and treating cocaine addiction.

Nicotine Replacement Therapy and Healthy Lifestyle Psychoeducation for Smoking Reduction in Acute Psychiatric Inpatients: A Cluster-Randomized Parallel Study

BACKGROUND

Effectiveness of nicotine replacement therapies in acute psychiatric inpatient settings remains under-researched. The aim of this study was to compare effectiveness and acceptability of 3 different forms of nicotine replacement therapy in achieving smoking reduction among acute psychiatric inpatients.

METHODS

This cluster-randomized, parallel study compared effectiveness and acceptability of nicotine inhalers, nicotine gum, and nicotine patches for smoking reduction in the acute psychiatric inpatient setting. The primary outcome was the exhaled breath carbon monoxide (CO) level change from baseline at weeks 4 and 8. Secondary outcomes included changes in nicotine withdrawal symptoms and psychiatric symptom severity.

RESULTS

Three hundred ten inpatients on the acute care wards were randomly assigned to nicotine inhalers (n = 184), gum (n = 71), and patches (n = 55). Only the nicotine inhaler group showed statistically significant reduction in CO level from baseline at both weeks 4 and 8 (P < 0.001 and P = 0.032, respectively). The nicotine inhaler and the patch group showed significant decrease in nicotine withdrawal symptoms from baseline at both weeks 4 and 8. Meanwhile, the nicotine inhaler and the gum group showed significant decrease in psychiatric symptom severity from baseline at both weeks 4 and 8. Post hoc comparisons revealed that the inhaler group had a greater decrease in psychiatric symptom severity compared with the patch group.

CONCLUSIONS

Nicotine inhalers may be an effective choice for smoking reduction in acute psychiatric inpatient settings given its significant effects on CO level, withdrawal symptoms, and psychiatric symptom severity, particularly during the first 4 weeks of treatment.

The treatment of cocaine use disorder

Cocaine use continues to be a serious worldwide public health problem. Cocaine abuse is associated with substantial morbidity and mortality. Cocaine overdose deaths are increasing in the United States and, in certain populations, outnumber heroin and opiate overdose deaths. Psychosocial treatments remain the treatments of choice for cocaine use disorder (CUD), with standard approaches including contingency management and cognitive behavioral therapy. However, the effect sizes of these treatments are not large, and they are not effective for most patients. Consequently, investigators have sought to develop pharmacological agents to augment the efficacy of psychosocial treatments. Despite these efforts, no medications have yet been proven to be safe and effective for the treatment of CUD. The most promising pharmacological strategies for CUD treatment thus far include the use of dopamine agonists, such as long-acting amphetamine and modafinil or glutamatergic and GABAergic agents such as topiramate. Combination drugs may be especially promising.

Persistent attenuation of nicotine self-administration in rats by co-administration of chronic nicotine infusion with the dopamine D1 receptor antagonist SCH-23390 or the serotonin 5-HT2C agonist lorcaserin

Tobacco addiction each year causes millions of deaths worldwide. Brain nicotinic acetylcholine receptors have been shown to be central to tobacco addiction. Nicotine replacement therapy aids tobacco cessation, but the success rate is still far too low. This may in part be due to the fact that neurons with nicotinic receptors are not the only neural systems involved in tobacco addiction. Interacting neural systems also play important roles in tobacco addiction. Nicotine increases the release of a variety of neurotransmitters, including dopamine and serotonin. Dopamine, in particular dopamine D₁ receptors, has been shown to be involved in the reinforcing action of nicotine. Serotonin through its actions on 5-HT_2C receptors has been shown to play a key role in modulating the reinforcement of addictive drugs, including nicotine and alcohol. Combination of treatments could provide greater treatment efficacy. These studies were conducted to evaluate combination therapies utilizing nicotine replacement therapy in conjunction with either a dopamine D₁ receptor antagonist SCH-23390 or a serotonin 5-HT_2C receptor agonist, lorcaserin. Female Sprague-Dawley rats were given access to self-administer nicotine via IV infusions. Osmotic pumps were implanted to reproduce the kinetic of chronic nicotine patch therapy. SCH-23390 (0.02 mg/kg) or lorcaserin (0.6 mg/kg) were administered prior to nicotine self-administration sessions. Reproducing earlier findings SCH-23390, lorcaserin and nicotine replacement therapy were effective at reducing IV nicotine self-administration. 5HT_2C agonist treatment had additive effects with chronic nicotine infusion for significantly lowering nicotine self-administration. This study demonstrates the feasibility of combination of chronic nicotine with therapies targeting non-nicotinic receptors as treatment options for tobacco addiction.

Amitifadine, a triple monoamine re-uptake inhibitor, reduces nicotine self-administration in female rats

A wider diversity of drug treatments to aid smoking cessation is needed to help tailor the most efficacious treatment for different types of smokers. This study was conducted to determine whether amitifadine, which inhibits re-uptake of dopamine, norepinephrine and serotonin, would decrease nicotine self-administration at doses that do not cause adverse side effects. Adult female Sprague-Dawley rats were trained to self-administer nicotine intravenous (IV) and were given acute doses of amitifadine in a repeated measures counterbalanced design. Effects of amitifadine on locomotor activity and food motivated responding were also evaluated. Chronic amitifadine effects were also examined. The 30 mg/kg amitifadine dose significantly reduced nicotine self-administration. The 5 and 10 mg/kg doses reduced nicotine self-administration during the first 15 min of the session when the greatest amount of nicotine was self-administered. The 30 mg/kg amitifadine dose, but not the lower doses caused a significant reduction in locomotor activity averaged over the one-hour session and reduced food motivated responding. The 10 mg/kg dose caused hypoactivity at the beginning of the session, but 5 mg/kg did not cause any hypoactivity. The effects of chronic amitifadine treatment (10 mg/kg) over the course of 15 sessions was also determined. Amitifadine caused a significant reduction in nicotine self-administration, which was not seen to diminish over two consecutive weeks of treatment and a week after enforced abstinence. Amitifadine significantly reduced nicotine self-administration. This prompts further research to determine if amitifadine might be an effective treatment for smoking cessation.

Pharmacological strategies for detoxification

Detoxification refers to the safe discontinuation from a substance of dependence and is distinct from relapse prevention. Detoxification usually takes between a few days and a few weeks to complete, depending on the substance being misused, the severity of dependence and the support available to the user. Psychosocial therapies alongside pharmacological treatments are essential to improve outcome. The dependencies considered in this overview are detoxification from opioids (with methadone, buprenorphine, α2-adrenoceptor agonists and adjunct medications), alcohol (with benzodiazepines, anti-glutamatergics and γ-aminobutyric acid (GABA)-ergic drugs), stimulants and cannabis (with no clear recommended pharmacological treatments), benzodiazepines (with dose tapering) and nicotine (with nicotine replacement therapy, antidepressants and partial agonists). Evidence is limited by a lack of controlled trials robust enough for review bodies, and more research is required into optimal treatment doses and regimes, alone and in combination.

[Tobacco use and illicit substance use disorders: what should we have to do?]

Tobacco use is a commonplace phenomenon in our society. Its use is responsible for more death and disease than any other noninfectious cause. More deaths are caused each year by tobacco use than by all deaths from HIV, illegal drug use, alcohol use, motor vehicle injuries, suicides, and murders combined. Tobacco remains responsible for greater morbidity than alcohol and all other drugs combined. Tobacco dependence is highly prevalent among drug-dependent patients. Substance abuse patients smoke more and are more vulnerable to the effects of smoking than general populations. Traditional substance abuse therapeutic programs too frequently focus only on treatment of alcohol or other drugs rather than including treatment for tobacco dependence. Currently, there are no official medical recommendations for the treatment of tobacco addiction in illicit polysubstance users.

METHODS

A comprehensive literature search from a range of electronic databases (PubMed, Embase, PsycInfo, Google Scholar) was conducted for the period from 1988 to September 2012, using the following keywords alone or in combination: tobacco, nicotine, cocaine, cannabis, amphetamines, opiates, substance abuse, substance dependence, addiction, treatment. There were no restrictions on the identification or inclusion of studies in terms of publication status, language and design type.

RESULTS

Our literature review will focus on epidemiological, neurobiological, clinical interactions between tobacco, alcohol and other illicit drugs. It will also focus on therapeutic programs in this dual addictive disorder. The aim of this literature review is to make proposals for the treatment of tobacco addiction in polysubstance users entering in specific therapeutic programs.

Availability of nicotine replacement therapy in substance use disorder treatment: longitudinal patterns of adoption, sustainability, and discontinuation

BACKGROUND

There is growing recognition regarding the clinical importance of integrating smoking cessation services, such as nicotine replacement therapy (NRT), within programs that treat substance use disorders (SUDs) since the majority of individuals receiving treatment also smoke. Previous research has not examined the organizational characteristics associated with NRT availability over time in SUD treatment programs.

METHOD

Using longitudinal data collected from administrators of 868 SUD treatment programs over a four-year period, the availability of NRT in the forms of the nicotine patch or nicotine gum was measured. Associations between organizational covariates and NRT adoption were estimated using multinomial logistic regression.

RESULTS

The rate of NRT availability significantly decreased over time from 38.0% of SUD programs at baseline to 33.8% at follow-up. The multinomial logistic regression model indicated programs that sustained adoption of NRT over time were more medically oriented, as measured by location in a hospital setting and access to physicians, and were less likely to offer outpatient services. Sustained and recent adopters of NRT were more likely to offer other smoking cessation interventions at follow- up than NRT discontinuers or NRT non-adopters.

CONCLUSIONS

These findings suggest that patients' access to NRT varies across different types of treatment organizations. Future research should continue to measure the availability of NRT and other smoking cessation interventions in SUD treatment since these services may help patients to quit smoking and reduce the likelihood of SUD relapse.

Nicotinic receptors and stages of nicotine dependence

Smoking is one of the leading causes of preventable death, where nicotine has been identified as the primary addictive constituent of tobacco. Consequently, there have been extensive investigations into the neuroadaptations that occur as nicotine dependence develops, where numerous neurological systems have been implicated. The focus of this review was on nicotinic acetylcholine receptor neuroadaptations that occur during the development of nicotine dependence. This focus was selected because (1) the nicotinic receptors are the primary binding sites for both nicotine and the most efficacious pharmacological smoking cessation treatments and (2) the receptors are located throughout the brain with considerable neuromodulatory ability. However, there was difficulty associated in outlining the role of nicotinic receptors in the development of nicotine dependence because it comprises a series of stages involving different neurological systems rather than a single state. To address this issue, the review adopts a novel approach and considers the role of nicotinic receptor subtypes at separate stages of the nicotine dependence cycle. This information was then used to examine the nicotinic receptor-related therapeutic mechanisms of three main pharmacological smoking cessation treatments.

Baclofen prevents drug-induced reinstatement of extinguished nicotine-seeking behaviour and nicotine place preference in rodents

The gamma-aminobutyric acid(GABA)-B receptor agonist baclofen is known to reduce drug intake in both animals and humans and to prevent reinstatement of cocaine-, opioid-, and alcohol-seeking in rats after a period of extinction, but its effect on nicotine reinstatement is unknown. This study investigated the effect of baclofen on nicotine-seeking reinstatement both using the extinction/reinstatement model of nicotine self-administration and conditioned place preference (CPP). Results showed that in rats previously trained to intravenously self-administer nicotine (30 microg/kg/inf) under a FR-1 schedule of reinforcement, acute nicotine (0.15 mg/kg) priming effectively reinstates nicotine-seeking behaviour following extinction. At doses used in this study (up to 2.5 mg/kg) baclofen alone did not affect locomotor activity and did not reinstate responding. However, baclofen dose-dependently attenuated drug-induced reinstatement of nicotine-seeking in rats. Moreover, baclofen (1.25 mg/kg) completely blocked nicotine-induced reinstatement of extinguished nicotine (0.3 mg/kg) CPP in mice. Altogether, our results showed that baclofen is able to antagonise reinstatement of nicotine-seeking and CPP triggered by nicotine primings, suggesting its potential clinical utility as an anti-relapse agent.

Smoking cessation pharmacotherapy

Cigarette smoking remains an important risk factor for premature cardiovascular disease and its many complications. There are clear benefits from treating tobacco dependence on the rate of clinical outcomes. In addition to behavioral therapies, various pharmacologic strategies have been developed to help achieve this goal. First-line therapies include nicotine replacement, bupropion and varenicline, a partial nicotine antagonist. Second-line treatments include clonidine and nortriptyline. Additional treatment strategies with less proven efficacy include monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, opioid receptor antagonists, bromocriptine, anti-anxiety drugs, nicotinic receptor antagonists (e.g. mecamylamine) and glucose tablets. Various approaches under investigation include inhibitors of the hepatic P450 enzyme (e.g. methoxsalen), cannabinoid-1 receptor antagonists (e.g. rimonabant), and nicotine vaccines.

Vaccines in development to prevent and treat atherosclerotic disease

Coronary heart disease (CHD) remains the leading cause of death in the United States. Immune mechanisms have been recently proposed to play an important role in the development of atherosclerotic plaques in CHD. Heat shock proteins and oxidized low-density lipoprotein are proinflammatory substances that have been shown to have an important role in the pathogenesis of atherosclerosis, and are now targets for clinical vaccine development. In addition, a vaccine has been developed to inhibit cholesteryl ester transfer protein. It is now recognized that many medications used to combat plaque development and rupture have significant anti-inflammatory effects and these effects are critical for drug efficacy. The influenza vaccine is associated with an atheroprotective effect. In addition, a nicotine vaccine, an antiangiotensin vaccine, and an anti-obesity vaccine may play a therapeutic role in modifying known risk factors for the development of atherosclerosis and its complications. This article reviews these vaccines as possible additions to the armamentarium of atheroprotective treatment modalities.

Resolution of oral lesions after tobacco cessation

BACKGROUND

Dentists and other health care professionals are familiar with the impact of tobacco on oral and general health. However, oral health care professionals do not often provide tobacco-cessation counseling to their patients, thus reflecting a significant disconnect between research and clinical practice. This report demonstrates the benefits of tobacco cessation in resolving oral lesions and improving overall periodontal and oral health.

METHODS

A 51-year-old white male presented to the University at Buffalo, School of Dental Medicine clinic requesting an oral and periodontal examination as part of a presurgical protocol prior to cardiac surgery. A review of the patient's history from a health questionnaire revealed that he was using smokeless tobacco every day. An oral examination revealed several white lesions (5 x 10 mm) on the maxillary right and left labial mucosa. The patient was provided with tobacco-cessation counseling as well as oral hygiene instructions and professional dental prophylaxis.

RESULTS

An oral examination 2 weeks after tobacco cessation revealed complete resolution of the oral lesions and overall improvement of periodontal and oral health.

CONCLUSION

Although the findings presented in this article are based only on a single case report, the improvement in the patient's oral health after cessation of tobacco use was dramatic and reinforces the belief that tobacco-cessation counseling should be a routine component of the standard of care for tobacco-using patients.

Spontaneous nicotine withdrawal potentiates the effects of stress in rats

Anxiety is a common symptom of nicotine withdrawal in humans, and may predict an inability to abstain from cigarette smoking. It is not clear if self-reports of anxiety during abstinence reflect increased baseline anxiety and/or increased responses to exogenous stressors. We hypothesized that nicotine withdrawal selectively exacerbates reactivity to aversive stimuli in rodents. Here, we investigated the effect of withdrawal from chronic nicotine administration (3.16 mg/kg per day base, delivered via subcutaneous osmotic minipumps) in the light-enhanced startle (LES) test in Wistar rats. In this procedure, baseline startle responding in the dark is compared to startle responding when the chamber is brightly lit. Bright illumination is aversive for rats and potentiates the startle response. Hence, this procedure allows comparisons of withdrawal effects on startle reactivity between relatively neutral and stressful contexts. We found that spontaneous nicotine withdrawal (24 h post-pump removal) did not influence baseline startle responding, but produced a selective increase in LES. Precipitated nicotine withdrawal through injections of one of two nicotinic acetylcholine receptor (nAChR) antagonists, dihydro-beta-erythroidine hydrobromide (DHbetaE: 0, 1.5, 3, or 6 mg/kg) or mecamylamine (0, 1, 2, or 4 mg/kg), did not influence baseline startle responding or LES. These results suggest that spontaneous nicotine withdrawal selectively potentiates responses to anxiogenic stimuli, but does not by itself produce a strong anxiogenic effect. These findings support the hypothesis that nicotine withdrawal exacerbates stress responding, and indicate LES may be a useful model to examine withdrawal effects on anxiety.

The use of bupropion SR in cigarette smoking cessation

Cigarette smoking remains the largest preventable cause of premature death in developed countries. Until recently nicotine replacement therapy (NRT) has been the only recognised form of treatment for smoking cessation. Bupropion, the first non-nicotine based drug for smoking cessation was licensed in the United States of America (US) in 1997 and in the United Kingdom (UK) in 2000 for smoking cessation in people aged 18 years and over. Bupropion exerts its effect primarily through the inhibition of dopamine reuptake into neuronal synaptic vesicles. It is also a weak noradrenalin reuptake inhibitor and has no effect on the serotonin system. Bupropion has proven efficacy for smoking cessation in a number of clinical trials, helping approximately one in five smokers to stop smoking. Up to a half of patients taking bupropion experience side effects, mainly insomnia and a dry mouth, which are closely linked to the nicotine withdrawal syndrome. Bupropion is rarely associated with seizures however care must be taken when co-prescribing with drugs that can lower seizure threshold. Also, bupropion is a potent enzyme inhibitor and can raise plasma levels of some drugs including antidepressants, antiarrhythmics and antipsychotics. Bupropion has been shown to be a safe and cost effective smoking cessation agent. Despite this, NRT remains the dominant pharmacotherapy to aid smoking cessation.

Update on the pharmacologic therapy for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease is a treatable disease characterized by progressive airflow limitation. Prevention of disease progression; improvement of symptoms, exercise tolerance, and health status; and decrease in exacerbations and mortality are the goals of management. Inhaled short-acting bronchodilators are recommended for symptoms in mild disease, whereas inhaled long-acting bronchodilators are recommended for maintenance therapy of daily symptoms. When symptoms are not controlled using one bronchodilator, combining bronchodilators may be more effective. Combining a long-acting beta-agonist with an inhaled corticosteroid is more effective than either agent alone. Several novel therapies are in different stages of development.

Smoking: a risk factor for progression of chronic kidney disease and for cardiovascular morbidity and mortality in renal patients--absence of evidence or evidence of absence?

Although it is beyond any doubt that smoking is the number one preventable cause of death in most countries, smoking as an independent progression factor in renal disease has been questioned against the background of evidence-based criteria. This is because information from large, randomized, prospective studies that investigate the effects of smoking on renal function in healthy individuals as well as in patients with primary or secondary renal disease are lacking. Since 2003, a substantial number of clinical and experimental data concerning the adverse renal effects of smoking have been published, including large, prospective, population-based, observational studies. These more recent data together with evidence from experimental studies clearly indicate that smoking is a relevant risk factor, conferring a substantial increase in risk for renal function deterioration. This review summarizes the present knowledge about the renal risks of smoking as well as the increased cardiovascular risk caused by smoking in patients with chronic kidney disease. The conclusion is that smoking is an important renal risk factor, and nephrologists have to invest more efforts to motivate patients to stop smoking.