Reduction of nicotine and ethanol intake in alcohol-preferring (UChB) female rats by the α4β2 nicotinic acetylcholine receptor partial agonists 5-bromocytisine and cytisine

Cytisine compared to combination nicotine replacement therapy to reduce cigarette consumption in relapsed smokers: protocol for a pilot randomized controlled trial

BACKGROUND

Cigarette smoking is a leading cause of death and disease, including those related to the cardiovascular system. Cytisine is a plant-based medication, which works in a similar mechanism to varenicline. It is safe, efficacious, and cost-effective for smoking cessation. While there are effective therapies such as nicotine replacement therapy, bupropion, varenicline, and cytisine for smoking cessation, relapse remains common. It is unclear how best to support these individuals. This study aims to assess the feasibility of randomizing patients who relapse to combination NRT or cytisine after admission to a cardiac hospital.

STUDY DESIGN

Randomized, two-group parallel feasibility trial.

METHODS

This trial will recruit relapsed smokers from the University of Ottawa Heart Institute. Participants will be randomized 1:1 to receive cytisine or combination NRT, alongside counseling and follow-up support. Feasibility outcomes include recruitment rates and treatment completion. Secondary outcomes include smoking cessation rates and adverse events. A total of 60 participants will be recruited using stratified randomization by sex to ensure gender balance. Data will be analyzed descriptively, focusing on feasibility and efficacy measures to inform future trials.

DISCUSSION

The primary aim of this study is to evaluate the feasibility of recruiting patients who were recently admitted to the hospital and have relapsed to smoking within 180 days post-discharge. This will inform future studies aimed at recruiting patients who have relapsed to understand how best to support them to quit smoking. This study will also compare the acceptability, efficacy, and safety of cytisine compared to combination NRT, as demonstrated in previous studies in other populations. Notably, cytisine's shorter regimen and natural composition broaden its appeal, potentially supporting a wider spectrum of people who smoke. The study's robust design, infrastructure, and expertise enhance its feasibility. Future research avenues, especially among cardiac patients and relapsed individuals, promise further insights, potentially transforming cessation strategies worldwide.

TRIAL REGISTRATION

Registered at Clinicaltrials.gov (CT04286295) on 14 March 2022. https://clinicaltrials.gov/study/NCT04286295?locStr=Canada&country=Canada&intr=Cytisine&rank=3 .

Adolescent alcohol drinking interaction with the gut microbiome: implications for adult alcohol use disorder

Reciprocal communication between the gut microbiota and the brain, commonly referred to as the "gut-brain-axis" is crucial in maintaining overall physiological homeostasis. Gut microbiota development and brain maturation (neuronal connectivity and plasticity) appear to be synchronized and to follow the same timeline during childhood (immature), adolescence (expansion) and adulthood (completion). It is important to note that the mesolimbic reward circuitry develops early on, whereas the maturation of the inhibitory frontal cortical neurons is delayed. This imbalance can lead to increased acquirement of reward-seeking and risk-taking behaviors during adolescence, and consequently eventuate in heightened risk for substance abuse. Thus, there is high initiation of alcohol drinking in early adolescence that significantly increases the risk of alcohol use disorder (AUD) in adulthood. The underlying causes for heightened AUD risk are not well understood. It is suggested that alcohol-associated gut microbiota impairment during adolescence plays a key role in AUD neurodevelopment in adulthood. Furthermore, alcohol-induced dysregulation of microglia, either directly or indirectly through interaction with gut microbiota, may be a critical neuroinflammatory pathway leading to neurodevelopmental impairments and AUD. In this review article, we highlight the influence of adolescent alcohol drinking on gut microbiota, gut-brain axis and microglia, and eventual manifestation of AUD. Furthermore, novel therapeutic interventions via gut microbiota manipulations are discussed briefly.