Nicotine replacement therapy versus control for smoking cessation

Abstract

Background Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence. Objectives To determine the e ectiveness and safety of nicotine replacement therapy (NRT), including gum, transdermal patch, intranasal spray and inhaled and oral preparations, for achieving long-term smoking cessation, compared to placebo or 'no NRT' interventions. Search methods We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search is July 2017. Selection criteria Randomized trials in people motivated to quit which compared NRT to placebo or to no treatment. We excluded trials that did not report cessation rates, and those with follow-up of less than six months. We recorded adverse events from included and excluded studies that compared NRT with placebo. Studies comparing di erent types, durations, and doses of NRT, and studies comparing NRT to other pharmacotherapies, are covered in separate reviews. Data collection and analysis Screening, data extraction and 'Risk of bias' assessment followed standard Cochrane methods. The main outcome measure was abstinence from smoking a er at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-e ect model. Main results We identified 136 studies; 133 with 64,640 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The majority of studies were conducted in adults and had similar numbers of men and women. People enrolled in the studies typically smoked at least 15 cigarettes a day at the start of the studies. We judged the evidence to be of high quality; we judged most studies to be at high or unclear risk of bias but restricting the analysis to only those studies at low risk of bias did not significantly alter the result. The RR of abstinence for any form of NRT relative to control was 1.55 (95% confidence interval (CI) 1.49 to 1.61). The pooled RRs for each type were 1.

Nicotine dependence (trait) and acute nicotinic stimulation (state) modulate attention but not cognitive control: converging fMRI evidence from Go-Nogo and Flanker tasks

“…The latter serves as a partial agonist at these receptors, acting as a weak agonist in the absence of nicotine, and as a partial antagonist in the presence of nicotine 17 . While the in vitro receptor binding mechanisms of these drugs and their efficacy at a clinical level is established [18][19][20] , it is less clear how their systemslevel neurobiological mechanisms affect the cognitive and affective deficits seen in the human NWS.…”

The efficacy of smoking cessation interventions in low‐ and middle‐income countries: a systematic review and meta‐analysis

“…We identified five RCTs of NRT (patches, gum), which is one of the most widely studied pharmacotherapies for smoking cessation [12,13]. We identified five RCTs of NRT (patches, gum), which is one of the most widely studied pharmacotherapies for smoking cessation [12,13].…”

“…There are still relatively few RCTs of smoking cessation in LMICs compared to high-income countries. We identified five RCTs of NRT (patches, gum), which is one of the most widely studied pharmacotherapies for smoking cessation [12,13]. A recent systematic review of 136 trials of NRT compared to placebo with a follow-up duration of at least 6 months [13] found an effect size of 1.55 (95% CI = 1.49-1.61), similar to the present analysis (OR = 1.76, 95% CI = 1.30-2.37), suggesting that NRT may have similar efficacy irrespective of the country.…”

“…We identified five RCTs of NRT (patches, gum), which is one of the most widely studied pharmacotherapies for smoking cessation [12,13]. A recent systematic review of 136 trials of NRT compared to placebo with a follow-up duration of at least 6 months [13] found an effect size of 1.55 (95% CI = 1.49-1.61), similar to the present analysis (OR = 1.76, 95% CI = 1.30-2.37), suggesting that NRT may have similar efficacy irrespective of the country. The low cost and high availability of NRT in LMICs make NRT an ideal pharmacotherapy for smoking cessation compared to other smoking cessation medications [48].…”

“…Our inability to predict the efficacy of these interventions in the diverse cultural, clinical and economic settings of LMICs has prompted local research in these regions [9,11]. While studies of LMICs populations were included in recent systematic reviews [12,13], they constitute only a small fraction of included studies. The rising prevalence of smoking in LMICs and the unique challenges of implementing smoking cessation in these regions mandate a specific focus on the efficacy of interventions for smoking cessation in LMICs in order to guide smoking cessation treatment efforts in these regions.…”