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JAMA Feb 2022More deaths in the US are attributed to cigarette smoking each year than to any other preventable cause. Approximately 34 million people and an estimated 14% of adults... (Review)
Review
IMPORTANCE
More deaths in the US are attributed to cigarette smoking each year than to any other preventable cause. Approximately 34 million people and an estimated 14% of adults in the US smoke cigarettes. If they stopped smoking, they could reduce their risk of tobacco-related morbidity and mortality and potentially gain up to 10 years of life.
OBSERVATIONS
Tobacco smoking is a chronic disorder maintained by physical nicotine dependence and learned behaviors. Approximately 70% of people who smoke cigarettes want to quit smoking. However, individuals who attempt to quit smoking make an average of approximately 6 quit attempts before achieving long-term abstinence. Both behavioral counseling and pharmacotherapy while using nicotine replacement therapy (NRT) products, varenicline, or bupropion are effective treatments when used individually, but they are most effective when combined. In a meta-analysis including 19 488 people who smoked cigarettes, the combination of medication and behavioral counseling was associated with a quit rate of 15.2% over 6 months compared with a quit rate of 8.6% with brief advice or usual care. The EAGLES trial, a randomized double-blind clinical trial of 8144 people who smoked, directly compared the efficacy and safety of varenicline, bupropion, nicotine patch, and placebo and found a significantly higher 6-month quit rate for varenicline (21.8%) than for bupropion (16.2%) and the nicotine patch (15.7%). Each therapy was more effective than placebo (9.4%). Combining a nicotine patch with other NRT products is more effective than use of a single NRT product. Combining drugs with different mechanisms of action, such as varenicline and NRT, has increased quit rates in some studies compared with use of a single product. Brief or intensive behavioral support can be delivered effectively in person or by telephone, text messages, or the internet. The combination of a clinician's brief advice to quit and assistance to obtain tobacco cessation treatment is effective when routinely administered to tobacco users in virtually all health care settings.
CONCLUSIONS AND RELEVANCE
Approximately 34 million people in the US smoke cigarettes and could potentially gain up to a decade of life expectancy by stopping smoking. First-line therapy should include both pharmacotherapy and behavioral support, with varenicline or combination NRT as preferred initial interventions.
Topics: Behavior Therapy; Bupropion; Drug Therapy, Combination; Electronic Nicotine Delivery Systems; Humans; Smoking Cessation; Smoking Cessation Agents; Tobacco Smoking; Tobacco Use Cessation Devices; Varenicline
PubMed: 35133411
DOI: 10.1001/jama.2022.0395 -
BMC Medicine Jul 2023Vaping cessation is virtually unexplored. The efficacy and safety of varenicline for vaping cessation has not been studied and rigorous research is required to advance... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Vaping cessation is virtually unexplored. The efficacy and safety of varenicline for vaping cessation has not been studied and rigorous research is required to advance best practice and outcomes for people who use electronic cigarettes (EC) and want to quit. The objective is to evaluate the efficacy and safety of varenicline (1 mg BID, administered for 12 weeks, with follow-up to week 24) combined with vaping cessation counseling in exclusive daily EC users intending to quit vaping.
METHODS
Design: Double-blind, randomized, parallel-group, placebo-controlled trial.
SETTING
The study took place at a University-run smoking cessation center.
PARTICIPANTS
People who exclusively use ECs daily and intend to quit vaping.
INTERVENTION
A total of 140 subjects were randomized to either varenicline (1 mg, administered twice daily for 12 weeks) plus counseling or placebo treatment (administered twice daily, for 12 weeks) plus counseling. The trial consisted of a 12-week treatment phase followed by a 12-week follow-up, nontreatment phase.
MAIN OUTCOMES AND MEASURES
The primary efficacy endpoint of the study was biochemically validated continuous abstinence rate (CAR) at weeks 4 to 12. Secondary efficacy end points were CAR at weeks 4 to 24 and 7-day point prevalence of vaping abstinence at weeks 12 and 24.
RESULTS
CAR was significantly higher for varenicline vs placebo at each interval: weeks 4-12, 40.0% and 20.0%, respectively (OR = 2.67, 95% CI = [1.25-5.68], P = 0.011); weeks 4-24, 34.3% for varenicline with counseling and 17.2% for placebo with counseling (OR = 2.52, 95% CI = [1.14-5.58], P = 0.0224). The 7-day point prevalence of vaping abstinence was also higher for the varenicline than placebo at each time point. Serious adverse events were infrequent in both groups and not treatment-related.
CONCLUSIONS
The findings of the present RCT indicate that inclusion of varenicline in a vaping cessation program for people who use electronic cigarettes and intending to quit may result in prolonged abstinence. These positive findings establish a benchmark of intervention effectiveness, may support the use of varenicline combined with counseling in vaping cessation programs, and may also help guiding future recommendations by health authorities and healthcare providers.
TRIAL REGISTRATION
The study has been registered in EUDRACT with Trial registration ID: 2016-000339-42.
Topics: Humans; Varenicline; Nicotinic Agonists; Vaping; Electronic Nicotine Delivery Systems; Benzazepines; Quinoxalines; Double-Blind Method; Counseling; Treatment Outcome
PubMed: 37403047
DOI: 10.1186/s12916-023-02919-2 -
JAMA Jul 2021Cytisine is more effective than placebo and nicotine replacement therapy for smoking cessation. However, cytisine has not been tested against the most effective smoking... (Comparative Study)
Comparative Study Randomized Controlled Trial
IMPORTANCE
Cytisine is more effective than placebo and nicotine replacement therapy for smoking cessation. However, cytisine has not been tested against the most effective smoking cessation medication, varenicline, which is associated with adverse events known to lead to discontinuation of therapy.
OBJECTIVE
To examine whether standard cytisine treatment (25 days) was at least as effective as standard varenicline treatment (84 days) for smoking cessation.
DESIGN, SETTING, AND PARTICIPANTS
This noninferiority, open-label randomized clinical trial with allocation concealment and blinded outcome assessment was undertaken in Australia from November 2017 through May 2019; follow-up was completed in January 2020. A total of 1452 Australian adult daily smokers willing to make a quit attempt were included. Data collection was conducted primarily by computer-assisted telephone interview, but there was an in-person visit to validate the primary outcome.
INTERVENTIONS
Treatments were provided in accordance with the manufacturers' recommended dosage: cytisine (n = 725), 1.5-mg capsules taken 6 times daily initially then gradually reduced over the 25-day course; varenicline (n = 727), 0.5-mg tablets titrated to 1 mg twice daily for 84 days (12 weeks). All participants were offered referral to standard telephone behavioral support.
MAIN OUTCOMES AND MEASURES
The primary outcome was 6-month continuous abstinence verified using a carbon monoxide breath test at 7-month follow-up. The noninferiority margin was set at 5% and the 1-sided significance threshold was set at .025.
RESULTS
Among 1452 participants who were randomized (mean [SD] age, 42.9 [12.7] years; 742 [51.1%] women), 1108 (76.3%) completed the trial. Verified 6-month continuous abstinence rates were 11.7% for the cytisine group and 13.3% for the varenicline group (risk difference, -1.62% [1-sided 97.5% CI, -5.02% to ∞]; P = .03 for noninferiority). Self-reported adverse events occurred less frequently in the cytisine group (997 events among 482 participants) compared with the varenicline group (1206 events among 510 participants) and the incident rate ratio was 0.88 (95% CI, 0.81 to 0.95; P = .002).
CONCLUSIONS AND RELEVANCE
Among daily smokers willing to quit, cytisine treatment for 25 days, compared with varenicline treatment for 84 days, failed to demonstrate noninferiority regarding smoking cessation.
TRIAL REGISTRATION
anzctr.org.au Identifier: ACTRN12616001654448.
Topics: Adult; Alkaloids; Azocines; Dreams; Female; Humans; Male; Middle Aged; Nausea; Quinolizines; Smoking Cessation; Smoking Cessation Agents; Treatment Outcome; Varenicline
PubMed: 34228066
DOI: 10.1001/jama.2021.7621 -
High Blood Pressure & Cardiovascular... Oct 2020Tobacco use is one of the major public health concerns and it is the most preventable cause of morbidity and mortality worldwide. Smoking cessation reduces subsequent... (Review)
Review
Tobacco use is one of the major public health concerns and it is the most preventable cause of morbidity and mortality worldwide. Smoking cessation reduces subsequent cardiovascular events and mortality. Smoking is a real chronic disorder characterized by the development of an addiction status mainly due to nicotine. This condition makes the smokers generally unable to quit smoking without help. Different strategies are available to treat smoking dependence that include both non-pharmacological (behavioral counselling) and pharmacological therapies. Currently, it is well accepted that smoking cessation drugs are effective and safe in real-world settings. Nicotine replacement therapy (NRT), varenicline, bupropion and cytisine are the main pharmacological strategies available for smoking cessation. Their efficacy and safety have been proved even in patients with chronic cardiovascular disease. Each of these drugs has peculiar characteristics and the clinician should customize the smoking cessation strategy based on currently available scientific evidence and patient's preference, paying particular attention to those patients having specific cardiovascular and psychiatric comorbidities. The present document aims to summarize the current viable pharmacological strategies for smoking cessation, also discussing the controversial issue regarding the use of alternative tobacco products, in order to provide useful practical indications to all physicians, mainly to those involved in cardiovascular prevention.
Topics: Alkaloids; Azocines; Bupropion; Clinical Decision-Making; Electronic Nicotine Delivery Systems; Humans; Quinolizines; Recurrence; Risk Factors; Smoking; Smoking Cessation; Smoking Cessation Agents; Tobacco Use Cessation Devices; Tobacco Use Disorder; Treatment Outcome; Varenicline
PubMed: 32578165
DOI: 10.1007/s40292-020-00396-9 -
Clinical Pharmacology and Therapeutics Jan 2022To complement real-world evidence (RWE) guidelines, the 2019 Structured Preapproval and Postapproval Comparative study design framework to generate valid and transparent... (Review)
Review
To complement real-world evidence (RWE) guidelines, the 2019 Structured Preapproval and Postapproval Comparative study design framework to generate valid and transparent real-world Evidence (SPACE) framework elucidated a process for designing valid and transparent real-world studies. As an extension to SPACE, here, we provide a structured framework for conducting feasibility assessments-a step-by-step guide to identify decision grade, fit-for-purpose data, which complements the United States Food and Drug Administration (FDA)'s framework for a RWE program. The process was informed by our collective experience conducting systematic feasibility assessments of existing data sources for pharmacoepidemiology studies to support regulatory decisions. Used with the SPACE framework, the Structured Process to Identify Fit-For-Purpose Data (SPIFD) provides a systematic process for conducting feasibility assessments to determine if a data source is fit for decision making, helping ensure justification and transparency throughout study development, from articulation of a specific and meaningful research question to identification of fit-for-purpose data and study design.
Topics: Data Collection; Decision Making; Feasibility Studies; Humans; Research Design; Varenicline; COVID-19 Drug Treatment
PubMed: 34716990
DOI: 10.1002/cpt.2466 -
The Cochrane Database of Systematic... May 2023Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting... (Review)
Review
BACKGROUND
Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). This is an update of a Cochrane Review first published in 2007.
OBJECTIVES
To assess the effectiveness of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation.
SEARCH METHODS
We searched the Cochrane Tobacco Addiction Group's Specialised Register in April 2022 for trials, using relevant terms in the title or abstract, or as keywords. The register is compiled from searches of CENTRAL, MEDLINE, Embase, and PsycINFO. SELECTION CRITERIA: We included randomised controlled trials that compared the treatment drug with placebo, another smoking cessation drug, e-cigarettes, or no medication. We excluded trials that did not report a minimum follow-up period of six months from baseline.
DATA COLLECTION AND ANALYSIS
We followed standard Cochrane methods. Our main outcome was abstinence from smoking at longest follow-up using the most rigorous definition of abstinence, preferring biochemically validated rates where reported. We pooled risk ratios (RRs), using the Mantel-Haenszel fixed-effect model. We also reported the number of people reporting serious adverse events (SAEs).
MAIN RESULTS
We included 75 trials of 45,049 people; 45 were new for this update. We rated 22 at low risk of bias, 18 at high risk, and 35 at unclear risk. We found moderate-certainty evidence (limited by heterogeneity) that cytisine helps more people to quit smoking than placebo (RR 1.30, 95% confidence interval (CI) 1.15 to 1.47; I = 83%; 4 studies, 4623 participants), and no evidence of a difference in the number reporting SAEs (RR 1.04, 95% CI 0.78 to 1.37; I = 0%; 3 studies, 3781 participants; low-certainty evidence). SAE evidence was limited by imprecision. We found no data on neuropsychiatric or cardiac SAEs. We found high-certainty evidence that varenicline helps more people to quit than placebo (RR 2.32, 95% CI 2.15 to 2.51; I = 60%, 41 studies, 17,395 participants), and moderate-certainty evidence that people taking varenicline are more likely to report SAEs than those not taking it (RR 1.23, 95% CI 1.01 to 1.48; I = 0%; 26 studies, 14,356 participants). While point estimates suggested increased risk of cardiac SAEs (RR 1.20, 95% CI 0.79 to 1.84; I = 0%; 18 studies, 7151 participants; low-certainty evidence), and decreased risk of neuropsychiatric SAEs (RR 0.89, 95% CI 0.61 to 1.29; I = 0%; 22 studies, 7846 participants; low-certainty evidence), in both cases evidence was limited by imprecision, and confidence intervals were compatible with both benefit and harm. Pooled results from studies that randomised people to receive cytisine or varenicline showed that more people in the varenicline arm quit smoking (RR 0.83, 95% CI 0.66 to 1.05; I = 0%; 2 studies, 2131 participants; moderate-certainty evidence) and reported SAEs (RR 0.67, 95% CI 0.44 to 1.03; I = 45%; 2 studies, 2017 participants; low-certainty evidence). However, the evidence was limited by imprecision, and confidence intervals incorporated the potential for benefit from either cytisine or varenicline. We found no data on neuropsychiatric or cardiac SAEs. We found high-certainty evidence that varenicline helps more people to quit than bupropion (RR 1.36, 95% CI 1.25 to 1.49; I = 0%; 9 studies, 7560 participants), and no clear evidence of difference in rates of SAEs (RR 0.89, 95% CI 0.61 to 1.31; I = 0%; 5 studies, 5317 participants), neuropsychiatric SAEs (RR 1.05, 95% CI 0.16 to 7.04; I = 10%; 2 studies, 866 participants), or cardiac SAEs (RR 3.17, 95% CI 0.33 to 30.18; I = 0%; 2 studies, 866 participants). Evidence of harms was of low certainty, limited by imprecision. We found high-certainty evidence that varenicline helps more people to quit than a single form of nicotine replacement therapy (NRT) (RR 1.25, 95% CI 1.14 to 1.37; I = 28%; 11 studies, 7572 participants), and low-certainty evidence, limited by imprecision, of fewer reported SAEs (RR 0.70, 95% CI 0.50 to 0.99; I = 24%; 6 studies, 6535 participants). We found no data on neuropsychiatric or cardiac SAEs. We found no clear evidence of a difference in quit rates between varenicline and dual-form NRT (RR 1.02, 95% CI 0.87 to 1.20; I = 0%; 5 studies, 2344 participants; low-certainty evidence, downgraded because of imprecision). While pooled point estimates suggested increased risk of SAEs (RR 2.15, 95% CI 0.49 to 9.46; I = 0%; 4 studies, 1852 participants) and neuropsychiatric SAEs (RR 4.69, 95% CI 0.23 to 96.50; I not estimable as events only in 1 study; 2 studies, 764 participants), and reduced risk of cardiac SAEs (RR 0.32, 95% CI 0.01 to 7.88; I not estimable as events only in 1 study; 2 studies, 819 participants), in all three cases evidence was of low certainty and confidence intervals were very wide, encompassing both substantial harm and benefit.
AUTHORS' CONCLUSIONS
Cytisine and varenicline both help more people to quit smoking than placebo or no medication. Varenicline is more effective at helping people to quit smoking than bupropion, or a single form of NRT, and may be as or more effective than dual-form NRT. People taking varenicline are probably more likely to experience SAEs than those not taking it, and while there may be increased risk of cardiac SAEs and decreased risk of neuropsychiatric SAEs, evidence was compatible with both benefit and harm. Cytisine may lead to fewer people reporting SAEs than varenicline. Based on studies that directly compared cytisine and varenicline, there may be a benefit from varenicline for quitting smoking, however further evidence could strengthen this finding or demonstrate a benefit from cytisine. Future trials should test the effectiveness and safety of cytisine compared with varenicline and other pharmacotherapies, and should also test variations in dose and duration. There is limited benefit to be gained from more trials testing the effect of standard-dose varenicline compared with placebo for smoking cessation. Further trials on varenicline should test variations in dose and duration, and compare varenicline with e-cigarettes for smoking cessation.
Topics: Humans; Smoking Cessation; Nicotine; Varenicline; Bupropion; Electronic Nicotine Delivery Systems; Tobacco Use Cessation Devices; Nicotinic Agonists; Alkaloids
PubMed: 37142273
DOI: 10.1002/14651858.CD006103.pub8 -
Drug and Alcohol Dependence Oct 2023Cytisine is a smoking cessation medication. This systematic review incorporates recently published randomized controlled trials (RCTs) to provide an updated... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cytisine is a smoking cessation medication. This systematic review incorporates recently published randomized controlled trials (RCTs) to provide an updated evidence-based assessment of cytisine's efficacy and safety.
METHODS
We searched Cochrane Library, MEDLINE, and EMBASE, for RCTs comparing cytisine to other smoking cessation treatments in adults who smoke.
PRIMARY OUTCOME
6-month biochemically verified continuous abstinence. Other outcomes: abstinence at longest follow-up, adverse events, mortality, and health-related quality of life (HRQOL). We used Grading of Recommendations Assessment, Development and Evaluation (GRADE) to assess evidence certainty.
RESULTS
We included 14 RCTs involving 9953 adults. Cytisine was superior to placebo (risk ratio [RR] 2.25, 95% confidence interval [CI] 1.13-4.47; 5 RCTs, 4325 participants), but not varenicline (RR 1.13, 95% CI 0.65-1.95; 2 RCTs, 2131 participants) for the primary outcome. Cytisine was superior to placebo (RR 2.78, 95% CI 1.64-4.70; 8 RCTs, 5762 participants) and nicotine replacement therapy [NRT] (RR 1.39, 95% CI 1.12-1.73; 2 RCTs, 1511 participants), but not varenicline (RR 1.02, 95% CI 0.72-1.44; 4 RCTs, 2708 participants) for abstinence at longest follow-up. Cytisine increased mostly gastrointestinal adverse events compared to placebo (RR 1.15; 95% CI 1.06-1.25; 8 RCTs, 5520 participants) and NRT (RR 1.52, 95% CI 1.26-1.84; 1 RCT, 1310 participants) but less adverse events compared to varenicline (RR 0.67; 95% CI 0.48-0.95; 3 RCTs, 2484 participants).
CONCLUSION
Cytisine shows greater efficacy than placebo and NRT, but more adverse events. It is comparable to varenicline, with fewer adverse events. This can inform clinicians and guidelines on cytisine for smoking cessation.
Topics: Adult; Humans; Varenicline; Smoking Cessation; Nicotinic Agonists; Nicotine; Bupropion; Benzazepines; Alkaloids; Azocines; Quinolizines
PubMed: 37678096
DOI: 10.1016/j.drugalcdep.2023.110936 -
American Family Physician Nov 2022In the United States, 1 in 5 adults uses tobacco products. Cigarette smoking is the leading cause of preventable disease and death in the United States despite its known...
In the United States, 1 in 5 adults uses tobacco products. Cigarette smoking is the leading cause of preventable disease and death in the United States despite its known health effects. Although nearly one-half of people who smoke try to quit each year, only up to 1 in 20 who quit without support achieve abstinence for at least six months. All patients, including school-aged children and adolescents, should be asked if they smoke and offered evidence-based treatments for smoking cessation. Use of the 5 A's framework (ask, advise, assess, assist, arrange) can help clinicians promote smoking cessation. Clinical studies have demonstrated that combining pharmacotherapy with effective behavior strategies is significantly more effective than either approach alone. Pharmacotherapies approved by the U.S. Food and Drug Administration for smoking cessation include nicotine replacement therapy, bupropion, and varenicline. Extended use (greater than 12 weeks) of a controller therapy (varenicline, bupropion, or nicotine patch) is associated with significantly higher sustained quit rates and lower relapse rates than standard use (six to 12 weeks). e-Cigarettes are not approved by the U.S. Food and Drug Administration for smoking cessation, and evidence supporting their benefit is inconclusive. Lung cancer screening is recommended for adults 50 to 80 years of age who have a 20-pack-year smoking history and currently smoke or have quit within the past 15 years. Lung cancer screening should be combined with smoking cessation tools and treatment.
Topics: Adult; Adolescent; Child; Humans; Young Adult; Varenicline; Tobacco Use Cessation Devices; Smoking Cessation; Bupropion; Electronic Nicotine Delivery Systems; Early Detection of Cancer; Lung Neoplasms; Neoplasm Recurrence, Local
PubMed: 36379496
DOI: No ID Found -
Ophthalmology Apr 2022To evaluate the efficacy and safety of OC-01 (varenicline solution) nasal spray for treatment of patients with dry eye disease. (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
To evaluate the efficacy and safety of OC-01 (varenicline solution) nasal spray for treatment of patients with dry eye disease.
DESIGN
Randomized, multicenter, double-masked, vehicle-controlled, phase 3 study.
PARTICIPANTS
Adults 22 years of age or older with a diagnosis of dry eye disease, artificial tear use, Ocular Surface Disease Index score of 23 or more, and Schirmer test score (STS) of 10 mm or less. Eligibility was not restricted by eye dryness score (EDS).
METHODS
Patients (N = 758) were randomized in a 1:1:1 ratio to twice-daily treatment with 50-μl intranasal spray in each nostril of OC-01 0.03 mg (n = 260), OC-01 0.06 mg (n = 246), or vehicle (control; n = 252) for 4 weeks (ClinicalTrials.gov identifier, NCT04036292).
MAIN OUTCOME MEASURES
The primary efficacy end point was the percentage of patients achieving a 10-mm improvement or more in STS at week 4. Secondary end points included change from baseline to week 4 in STS and EDS in a controlled adverse environment (CAE) chamber and in the clinic. Treatment-emergent adverse events (TEAEs) were assessed.
RESULTS
A statistically significantly greater percentage of patients achieved the primary end point in both OC-01 treatment groups compared with the vehicle group (OC-01 0.03 mg, 47.3%; OC-01 0.06 mg, 49.2%; vehicle, 27.8%; P < 0.0001 for both doses). Change from baseline in STS at week 4 was statistically significantly greater for patients receiving OC-01 than vehicle (P < 0.0001 for both doses). Eye dryness score assessed at week 4 improved with OC-01 treatment compared with vehicle, although the difference was not significant for EDS measured in the CAE chamber and showed (nominal) significance in the clinic. Overall, 86.5% of patients (654/756) reported at least 1 TEAE during the treatment period; most were mild, nonocular (sneezing, cough, throat irritation, and instillation site irritation) and were reported by fewer patients in the vehicle group than in the OC-01 treatment groups (OC-01 0.03 mg, 97.3%; OC-01 0.06 mg, 99.2%; vehicle, 57%).
CONCLUSIONS
OC-01 nasal spray was well tolerated and showed a clinically meaningful effect on signs and symptoms of dry eye disease.
Topics: Adult; Double-Blind Method; Dry Eye Syndromes; Humans; Lubricant Eye Drops; Nasal Sprays; Ophthalmic Solutions; Tears; Treatment Outcome; Varenicline
PubMed: 34767866
DOI: 10.1016/j.ophtha.2021.11.004 -
The Cochrane Database of Systematic... Sep 2023Tobacco smoking is the leading preventable cause of death and disease worldwide. Stopping smoking can reduce this harm and many people would like to stop. There are a... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Tobacco smoking is the leading preventable cause of death and disease worldwide. Stopping smoking can reduce this harm and many people would like to stop. There are a number of medicines licenced to help people quit globally, and e-cigarettes are used for this purpose in many countries. Typically treatments work by reducing cravings to smoke, thus aiding initial abstinence and preventing relapse. More information on comparative effects of these treatments is needed to inform treatment decisions and policies.
OBJECTIVES
To investigate the comparative benefits, harms and tolerability of different smoking cessation pharmacotherapies and e-cigarettes, when used to help people stop smoking tobacco.
SEARCH METHODS
We identified studies from recent updates of Cochrane Reviews investigating our interventions of interest. We updated the searches for each review using the Cochrane Tobacco Addiction Group (TAG) specialised register to 29 April 2022.
SELECTION CRITERIA
We included randomised controlled trials (RCTs), cluster-RCTs and factorial RCTs, which measured smoking cessation at six months or longer, recruited adults who smoked combustible cigarettes at enrolment (excluding pregnant people) and randomised them to approved pharmacotherapies and technologies used for smoking cessation worldwide (varenicline, cytisine, nortriptyline, bupropion, nicotine replacement therapy (NRT) and e-cigarettes) versus no pharmacological intervention, placebo (control) or another approved pharmacotherapy. Studies providing co-interventions (e.g. behavioural support) were eligible if the co-intervention was provided equally to study arms.
DATA COLLECTION AND ANALYSIS
We followed standard Cochrane methods for screening, data extraction and risk of bias (RoB) assessment (using the RoB 1 tool). Primary outcome measures were smoking cessation at six months or longer, and the number of people reporting serious adverse events (SAEs). We also measured withdrawals due to treatment. We used Bayesian component network meta-analyses (cNMA) to examine intervention type, delivery mode, dose, duration, timing in relation to quit day and tapering of nicotine dose, using odds ratios (OR) and 95% credibility intervals (CrIs). We calculated an effect estimate for combination NRT using an additive model. We evaluated the influence of population and study characteristics, provision of behavioural support and control arm rates using meta-regression. We evaluated certainty using GRADE.
MAIN RESULTS
Of our 332 eligible RCTs, 319 (835 study arms, 157,179 participants) provided sufficient data to be included in our cNMA. Of these, we judged 51 to be at low risk of bias overall, 104 at high risk and 164 at unclear risk, and 118 reported pharmaceutical or e-cigarette/tobacco industry funding. Removing studies at high risk of bias did not change our interpretation of the results. Benefits We found high-certainty evidence that nicotine e-cigarettes (OR 2.37, 95% CrI 1.73 to 3.24; 16 RCTs, 3828 participants), varenicline (OR 2.33, 95% CrI 2.02 to 2.68; 67 RCTs, 16,430 participants) and cytisine (OR 2.21, 95% CrI 1.66 to 2.97; 7 RCTs, 3848 participants) were associated with higher quit rates than control. In absolute terms, this might lead to an additional eight (95% CrI 4 to 13), eight (95% CrI 6 to 10) and seven additional quitters per 100 (95% CrI 4 to 12), respectively. These interventions appeared to be more effective than the other interventions apart from combination NRT (patch and a fast-acting form of NRT), which had a lower point estimate (calculated additive effect) but overlapping 95% CrIs (OR 1.93, 95% CrI 1.61 to 2.34). There was also high-certainty evidence that nicotine patch alone (OR 1.37, 95% CrI 1.20 to 1.56; 105 RCTs, 37,319 participants), fast-acting NRT alone (OR 1.41, 95% CrI 1.29 to 1.55; 120 RCTs, 31,756 participants) and bupropion (OR 1.43, 95% CrI 1.26 to 1.62; 71 RCTs, 14,759 participants) were more effective than control, resulting in two (95% CrI 1 to 3), three (95% CrI 2 to 3) and three (95% CrI 2 to 4) additional quitters per 100 respectively. Nortriptyline is probably associated with higher quit rates than control (OR 1.35, 95% CrI 1.02 to 1.81; 10 RCTs, 1290 participants; moderate-certainty evidence), resulting in two (CrI 0 to 5) additional quitters per 100. Non-nicotine/placebo e-cigarettes (OR 1.16, 95% CrI 0.74 to 1.80; 8 RCTs, 1094 participants; low-certainty evidence), equating to one additional quitter (95% CrI -2 to 5), had point estimates favouring the intervention over control, but CrIs encompassed the potential for no difference and harm. There was low-certainty evidence that tapering the dose of NRT prior to stopping treatment may improve effectiveness; however, 95% CrIs also incorporated the null (OR 1.14, 95% CrI 1.00 to 1.29; 111 RCTs, 33,156 participants). This might lead to an additional one quitter per 100 (95% CrI 0 to 2). Harms There were insufficient data to include nortriptyline and non-nicotine EC in the final SAE model. Overall rates of SAEs for the remaining treatments were low (average 3%). Low-certainty evidence did not show a clear difference in the number of people reporting SAEs for nicotine e-cigarettes, varenicline, cytisine or NRT when compared to no pharmacotherapy/e-cigarettes or placebo. Bupropion may slightly increase rates of SAEs, although the CrI also incorporated no difference (moderate certainty). In absolute terms bupropion may cause one more person in 100 to experience an SAE (95% CrI 0 to 2).
AUTHORS' CONCLUSIONS
The most effective interventions were nicotine e-cigarettes, varenicline and cytisine (all high certainty), as well as combination NRT (additive effect, certainty not rated). There was also high-certainty evidence for the effectiveness of nicotine patch, fast-acting NRT and bupropion. Less certain evidence of benefit was present for nortriptyline (moderate certainty), non-nicotine e-cigarettes and tapering of nicotine dose (both low certainty). There was moderate-certainty evidence that bupropion may slightly increase the frequency of SAEs, although there was also the possibility of no increased risk. There was no clear evidence that any other tested interventions increased SAEs. Overall, SAE data were sparse with very low numbers of SAEs, and so further evidence may change our interpretation and certainty. Future studies should report SAEs to strengthen certainty in this outcome. More head-to-head comparisons of the most effective interventions are needed, as are tests of combinations of these. Future work should unify data from behavioural and pharmacological interventions to inform approaches to combined support for smoking cessation.
Topics: Adult; Female; Humans; Pregnancy; Bupropion; Electronic Nicotine Delivery Systems; Network Meta-Analysis; Nicotine; Nortriptyline; Smoking Cessation; Varenicline
PubMed: 37696529
DOI: 10.1002/14651858.CD015226.pub2