Topiramate for smoking cessation: Systematic review and meta-analysis

A Double-Blind, Placebo-Controlled Study of Adjunctive Topiramate in Adolescents With Co-Occurring Bipolar and Cannabis Use Disorders

Objective

To evaluate the efficacy of adjunctive topiramate (TPM) for the treatment of cannabis use disorder in adolescents with bipolar I disorder.

Method

We conducted a 16-week, double-blind, randomized, placebo-controlled investigation of quetiapine plus TPM (median dose = 208 mg) vs quetiapine plus placebo in adolescents with bipolar I and cannabis use disorder. All subjects participated in a Motivational Interview and Compliance Enhancement Therapy. The primary outcome measure was change in weekly cannabis use over a 16-week treatment period using the Timeline Followback. The secondary outcome measure was the baseline-to-endpoint total score change in the Young Mania Rating Scale (YMRS).

Results

A total of 75 participants completed at least 1 post-baseline assessment (TPM = 38, placebo = 37). There was a significant time-by-treatment effect over the 16-week treatment period, with baseline-adjusted treatment differences in favor of the TPM group over time (p < .001). Although there was no difference in baseline-to-endpoint YMRS total score change between groups (p = .342), there was as significant decline in YMRS total score within both groups (p < .0001). There was a significant positive effect for alcohol use (p < .001) and nicotine use (p = .033) in the TPM group. More participants in the TPM group experienced appetite decrease (p = .032) and excitement (p = .025). Participants in the placebo group experienced greater weight gain (p = .010).

Conclusion

Treatment with TPM adjunctive to quetiapine and a Motivational Interview and Compliance Enhancement Therapy is associated with a greater decrease in cannabis use and less weight gain. TPM is a well-tolerated and efficacious treatment for cannabis use disorder in adolescents with bipolar I disorder.

Clinical trial registration information

Efficacy Study of Quetiapine Plus Topiramate for Reducing Cannabis Consumption and Bipolar Mania; https://clinicaltrials.gov/; NCT00393978.

Diversity & Inclusion Statement

We worked to ensure sex and gender balance in the recruitment of human participants. We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science.

Integrative Pharmacology in the Treatment of Substance Use Disorders

The detrimental physical, mental, and socioeconomic effects of substance use disorders (SUDs) have been apparent to the medical community for decades. However, it has become increasingly urgent in recent years to develop novel pharmacotherapies to treat SUDs. Currently, practitioners typically rely on monotherapy. Monotherapy has been shown to be superior to no treatment at all for most substance classes. However, many randomized controlled trials (RCTs) have revealed that monotherapy leads to poorer outcomes when compared with combination treatment in all specialties of medicine. The results of RCTs suggest that monotherapy frequently fails since multiple dysregulated pathways, enzymes, neurotransmitters, and receptors are involved in the pathophysiology of SUDs. As such, research is urgently needed to determine how various neurobiological mechanisms can be targeted by novel combination treatments to create increasingly specific yet exceedingly comprehensive approaches to SUD treatment. This article aims to review the neurobiology that integrates many pathophysiologic mechanisms and discuss integrative pharmacology developments that may ultimately improve clinical outcomes for patients with SUDs. Many neurobiological mechanisms are known to be involved in SUDs including dopaminergic, nicotinic, N-methyl-D-aspartate (NMDA), and kynurenic acid (KYNA) mechanisms. Emerging evidence indicates that KYNA, a tryptophan metabolite, modulates all these major pathophysiologic mechanisms. Therefore, achieving KYNA homeostasis by harmonizing integrative pathophysiology and pharmacology could prove to be a better therapeutic approach for SUDs. We propose KYNA-NMDA-α7nAChRcentric pathophysiology, the "conductor of the orchestra," as a novel approach to treat many SUDs concurrently. KYNA-NMDA-α7nAChR pathophysiology may be the "command center" of neuropsychiatry. To date, extant RCTs have shown equivocal findings across comparison conditions, possibly because investigators targeted single pathophysiologic mechanisms, hit wrong targets in underlying pathophysiologic mechanisms, and tested inadequate monotherapy treatment. We provide examples of potential combination treatments that simultaneously target multiple pathophysiologic mechanisms in addition to KYNA. Kynurenine pathway metabolism demonstrates the greatest potential as a target for neuropsychiatric diseases. The investigational medications with the most evidence include memantine, galantamine, and N-acetylcysteine. Future RCTs are warranted with novel combination treatments for SUDs. Multicenter RCTs with integrative pharmacology offer a promising, potentially fruitful avenue to develop novel therapeutics for the treatment of SUDs.

Tobacco and nicotine use

Tobacco smoking is a major determinant of preventable morbidity and mortality worldwide. More than a billion people smoke, and without major increases in cessation, at least half will die prematurely from tobacco-related complications. In addition, people who smoke have a significant reduction in their quality of life. Neurobiological findings have identified the mechanisms by which nicotine in tobacco affects the brain reward system and causes addiction. These brain changes contribute to the maintenance of nicotine or tobacco use despite knowledge of its negative consequences, a hallmark of addiction. Effective approaches to screen, prevent and treat tobacco use can be widely implemented to limit tobacco's effect on individuals and society. The effectiveness of psychosocial and pharmacological interventions in helping people quit smoking has been demonstrated. As the majority of people who smoke ultimately relapse, it is important to enhance the reach of available interventions and to continue to develop novel interventions. These efforts associated with innovative policy regulations (aimed at reducing nicotine content or eliminating tobacco products) have the potential to reduce the prevalence of tobacco and nicotine use and their enormous adverse impact on population health.

The effects of pharmacological interventions on smoking cessation in people with alcohol dependence: A systematic review and meta-analysis of nine randomized controlled trials

BACKGROUND

Pharmacotherapies are widely used for smoking cessation. However, their efficacy for people with alcohol dependence remains unclear.

OBJECTIVE

This study aimed to explore the effects of pharmacotherapies on smoking cessation for people with alcohol dependence.

METHODS

Five electronic databases were searched in January 2021 for randomized controlled trials (RCTs) reporting the use of pharmacotherapies to promote smoking cessation in people with alcohol dependence. The risk of bias was assessed using the Cochrane tool. RevMan version 5.3 was used to perform meta-analyses of the changes in smoking behaviour, and the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence.

RESULTS

The search identified nine RCTs involving 908 smokers with alcohol dependence; eight were published in the USA and one in Canada. The risk of bias was low in three studies and unclear in the remaining six. The meta-analysis results showed that, compared with the placebo group, Varenicline had a significant effect on short-term smoking cessation (three RCTs, odds ratio [OR] = 6.27, 95% confidence interval [CI]: [2.49, 15.78], P < .05, very low certainty). Naltrexone had no significant effect on smoking cessation in short-term or long-term observations (three RCTs, OR = 0.99, 95% CI: [0.54, 1.81], P = .97, moderate certainty), and Topiramate had no significant effects (two RCTs, OR = 1.56, 95% CI: [0.67, 3.46], P > .05, low certainty). Only one trial reported that Bupropion did not affect smoking cessation.

CONCLUSION

Varenicline may promote smoking cessation in people with alcohol dependence. However, Naltrexone, Topiramate and Bupropion have no clear effect on increasing smoking abstinence among drinkers. The small number of studies and the low certainty of evidence indicate that the results should be interpreted cautiously.