Use of beta-blocking agents with group therapy in a smoking withdrawal clinic

Effectiveness of drugs acting on adrenergic receptors in the treatment for tobacco or alcohol use disorders: systematic review and meta-analysis

AIM

To assess the efficacy of drugs directly acting on alpha- and beta-adrenergic receptors in the treatment of patients suffering from tobacco or alcohol use disorder.

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, studies were identified through PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials and clinicaltrial.gov. We selected only randomized controlled trials with adult patients with tobacco or alcohol use disorders according to DSM-5 criteria. Interventions included any molecule having a direct pharmacological action on alpha- or beta-adrenergic receptors (agonist or antagonist). Comparators were placebo or other validated pharmacotherapies. The duration of the intervention was a minimum of 1 month, with 3 months of follow-up. Measurements included smoking cessation for tobacco; for alcohol, we selected abstinence, alcohol consumption (drinks per day or week) and heavy drinking days (HDD). Ten studies with tobacco and six with alcohol use disorder were included in the qualitative synthesis and fifteen studies in the quantitative analysis.

RESULTS

We found that clonidine, an alpha-2 agonist, significantly increased smoking abstinence [relative risk = 1.39 with a 95% confidence interval (CI) = 1.04, 1.84]. Beta-blockers had no significant effect on smoking abstinence. The alpha-1 antagonists prazosin and doxazosin decreased alcohol consumption [SMD = -0.32 (-0.56, -0.07)] but had no effect on abstinence or HDD.

CONCLUSIONS

The noradrenaline system may represent a promising mechanism to target in tobacco and alcohol use disorders.

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.

Anxiolytics for smoking cessation

BACKGROUND

There are two reasons to believe anxiolytics might help in smoking cessation. Anxiety may be a symptom of nicotine withdrawal. Second, smoking appears to be due, in part, to deficits in dopamine, serotonin and norepinephrine, all of which are increased by anxiolytics and antidepressants.

OBJECTIVES

The aim of this review is to assess the effectiveness of anxiolytic drugs in aiding long term smoking cessation. The drugs include buspirone; diazepam; doxepin; meprobamate; ondansetron; and the beta-blockers metoprolol, oxprenolol and propanolol.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register which includes trials indexed in Medline, Embase, SciSearch and PsycLit, and meetings abstracts.

SELECTION CRITERIA

We considered randomized trials comparing anxiolytic drugs to placebo or an alternative therapeutic control for smoking cessation. We excluded trials with less than 6 months follow-up.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of study population, the nature of the drug therapy, the outcome measures, method of randomisation, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months 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

There was one trial each of the anxiolytics diazepam, meprobamate, metoprolol and oxprenolol. There were two trials of the anxiolytic buspirone. None of the trials showed strong evidence of an effect for any of these drugs in helping smokers to quit. However, confidence intervals were wide, and an effect of anxiolytics cannot be ruled out on current evidence.

REVIEWER'S CONCLUSIONS

There is no consistent evidence that anxiolytics aid smoking cessation, but the available evidence does not rule out a possible effect.

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.