Varenicline versus placebo for waterpipe smoking cessation: a double-blind randomized controlled trial

Interventions for waterpipe smoking cessation

BACKGROUND

While cigarette smoking has declined globally, waterpipe smoking is rising, especially among youth. The impact of this rise is amplified by mounting evidence of its addictive and harmful nature. Waterpipe smoking is influenced by multiple factors, including appealing flavors, marketing, use in social settings, and misperceptions that waterpipe is less harmful or addictive than cigarettes. People who use waterpipes are interested in quitting, but are often unsuccessful at doing so on their own. Therefore, developing and testing waterpipe cessation interventions to help people quit was identified as a priority for global tobacco control efforts.  OBJECTIVES: To evaluate the effectiveness of tobacco cessation interventions for people who smoke waterpipes.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Review Group Specialized Register from database inception to 29 July 2022, using variant terms and spellings ('waterpipe' or 'narghile' or 'arghile' or 'shisha' or 'goza' or 'narkeela' or 'hookah' or 'hubble bubble'). We searched for trials, published or unpublished, in any language.

SELECTION CRITERIA

We sought randomized controlled trials (RCTs), quasi-RCTs, or cluster-RCTs of any smoking cessation interventions for people who use waterpipes, of any age or gender. In order to be included, studies had to measure waterpipe abstinence at a three-month follow-up or longer.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was abstinence from waterpipe use at least three months after baseline. We also collected data on adverse events. Individual study effects and pooled effects were summarized as risk ratios (RR) and 95% confidence intervals (95% CI), using Mantel-Haenszel random-effects models to combine studies, where appropriate. We assessed statistical heterogeneity with the I2 statistic. We summarized secondary outcomes narratively. We used the five GRADE considerations (risk of bias, inconsistency of effect, imprecision, indirectness, and publication bias) to assess the certainty of the body of evidence for our primary outcome in four categories high, moderate, low, or very low.

MAIN RESULTS

This review included nine studies, involving 2841 participants. All studies were conducted in adults, and were carried out in Iran, Vietnam, Syria, Lebanon, Egypt, Pakistan, and the USA. Studies were conducted in several settings, including colleges/universities, community healthcare centers, tuberculosis hospitals, and cancer treatment centers, while two studies tested e-health interventions (online web-based educational intervention, text message intervention). Overall, we judged three studies to be at low risk of bias, and six studies at high risk of bias. We pooled data from five studies (1030 participants) that tested intensive face-to-face behavioral interventions compared with brief behavioral intervention (e.g. one behavioral counseling session), usual care (e.g. self-help materials), or no intervention. In our meta-analysis, we included people who used waterpipe exclusively, or with another form of tobacco. Overall, we found low-certainty evidence of a benefit of behavioral support for waterpipe abstinence (RR 3.19 95% CI 2.17 to 4.69; I2 = 41%; 5 studies, N = 1030). We downgraded the evidence because of imprecision and risk of bias. We pooled data from two studies (N = 662 participants) that tested varenicline combined with behavioral intervention compared with placebo combined with behavioral intervention. Although the point estimate favored varenicline, 95% CIs were imprecise, and incorporated the potential for no difference and lower quit rates in the varenicline groups, as well as a benefit as large as that found in cigarette smoking cessation (RR 1.24, 95% CI 0.69 to 2.24; I2 = 0%; 2 studies, N = 662; low-certainty evidence). We downgraded the evidence because of imprecision. We found no clear evidence of a difference in the number of participants experiencing adverse events (RR 0.98, 95% CI 0.67 to 1.44; I2 = 31%; 2 studies, N = 662). The studies did not report serious adverse events.   One study tested the efficacy of seven weeks of bupropion therapy combined with behavioral intervention. There was no clear evidence of benefit for waterpipe cessation when compared with behavioral support alone (RR 0.77, 95% CI 0.42 to 1.41; 1 study, N = 121; very low-certainty evidence), or with self-help (RR 1.94, 95% CI 0.94 to 4.00; 1 study, N = 86; very low-certainty evidence).  Two studies tested e-health interventions. One study reported higher waterpipe quit rates among participants randomized to either a tailored mobile phone or untailored mobile phone intervention compared with those randomized to no intervention (RR 1.48, 95% CI 1.07 to 2.05; 2 studies, N = 319; very low-certainty evidence). Another study reported higher waterpipe abstinence rates following an intensive online educational intervention compared with a brief online educational intervention (RR 1.86, 95% CI 1.08 to 3.21; 1 study, N = 70; very low-certainty evidence).  AUTHORS' CONCLUSIONS: We found low-certainty evidence that behavioral waterpipe cessation interventions can increase waterpipe quit rates among waterpipe smokers. We found insufficient evidence to assess whether varenicline or bupropion increased waterpipe abstinence; available evidence is compatible with effect sizes similar to those seen for cigarette smoking cessation.  Given e-health interventions' potential reach and effectiveness for waterpipe cessation, trials with large samples and long follow-up periods are needed. Future studies should use biochemical validation of abstinence to prevent the risk of detection bias. Finally, there has been limited attention given to high-risk groups for waterpipe smoking, such as youth, young adults, pregnant women, and dual or poly tobacco users. These groups would benefit from targeted studies.

Effects of varenicline on the serum levels of olanzapine in male patients with Schizophrenia: a randomized controlled trial

Background

Smoking in patients with Schizophrenia is more common than in the general population. Varenicline, a partial agonist at α4β2 nicotinic acetylcholine receptors, is an effective smoking cessation pharmacotherapy in patients with Schizophrenia. However, its effects on the serum levels of antipsychotics in Schizophrenia are understudied. This study investigated the impact of smoking cessation with varenicline on the serum concentration of olanzapine in patients with Schizophrenia.

Methods

Adult smokers with Schizophrenia were enrolled in a 12-week course of varenicline and placebo for smoking cessation. The serum concentration of olanzapine was measured at baseline and weeks 1, 2, 4, 8, and 12. Data were analyzed with the generalized additive mixed model.

Results

During the 12-week study, the results indicated that olanzapine concentrations increased nonlinearly in the varenicline and placebo groups. Threshold effect analysis suggested that the olanzapine concentrations increased over time until the turning point (week 4). However, there was no significant difference between the two treatment groups.

Conclusion

Varenicline showed safety and efficacy in smoking cessation in people with Schizophrenia.

Varenicline Treatment for Waterpipe Smoking Cessation

BACKGROUND

Waterpipe smoking is increasing worldwide with no proven interventions for cessation. We compared abstinence rates with 12-week varenicline therapy versus placebo among habitual waterpipe smokers willing to quit.

METHODS

This double-blind placebo-controlled single-center trial, randomized waterpipe smokers from Lebanon who did not smoke other tobacco products to receive varenicline or placebo for 12 weeks. All participants also received three structured 30-minute individual behavioral intervention sessions. The primary outcome was repeated point prevalence abstinence assessed by self-report and verified by exhaled carbon monoxide three times during 12 weeks and analyzed with the intention to treat. End of treatment urine cotinine, weight, blood pressure, anxiety, depression, withdrawal, and adverse symptoms were also assessed.

RESULTS

In total, 152 waterpipe smokers (mean age 38 years [SD = 13], 39% females) willing to quit, who smoked waterpipe exclusively (average 2.3 per day [SD = 1.6] for 16.8 years [SD = 10.8]) were randomized. Seventy-nine participants (52%) with any missing abstinence assessment were considered to have relapsed. Repeat point prevalence abstinence rate was numerically higher among the varenicline group compared to placebo, but the difference did not reach statistical significance when assessed by self-report (16.9 vs. 13.6%, respectively, p = .6) and when further verified by exhaled carbon monoxide (14.1% vs. 9.9%, respectively, p = .4). Abstinence rates were similar in both groups when further verified by urine cotinine at end of treatment. No serious adverse events were reported, adverse symptoms and other outcomes were similar in the varenicline and placebo arms.

CONCLUSIONS

Varenicline for 12 weeks was not more effective than placebo to achieve abstinence among daily waterpipe smokers.

IMPLICATIONS

Varenicline in combination with a behavioral intervention did not significantly enhance the quit rate among exclusive waterpipe smokers compared to behavioral intervention plus placebo. We experienced difficulty enrolling exclusive waterpipe smokers willing to quit and observed high dropout rates among participants demonstrating the difficulties of waterpipe smoking cessation.

What factors are associated with waterpipe smoking cessation? A secondary data analysis

INTRODUCTION

Waterpipe smoking is gaining popularity and becoming a major global public health concern. An understanding of factors that predict waterpipe smoking cessation is necessary for targeting tobacco control efforts.

METHODS

This is a secondary data analysis of a randomised controlled-trial comparing the efficacy of varenicline against placebo in helping waterpipe smokers to quit. A total of 510 adult daily waterpipe smokers were recruited to the trial in 2016. Logistic regression models were applied to assess factors (i.e., demographic, environmental, behavioural, and physiological) associated with primary outcome (waterpipe smoking cessation) and secondary outcomes (waterpipe cessation alongside abstinence from cigarette and short-term and long-term waterpipe smoking cessation). Cessation was defined as 7-day point prevalence abstinence from smoking reported at 5,12, and/or 25 weeks follow ups.

RESULTS

Over a period of six months, 189 (39.2%) participants abstained from waterpipe smoking for at least one week. Being male (adjusted odds ratio (aOR):2.99 (95%CI:1.47-6.08)), dual smoker (waterpipe and cigarettes) (aOR:2.98 (95%CI:1.87-4.74)), more withdrawal symptoms measured by the Mood and Physical Symptoms Scale (aOR:1.08 (95%CI:1.02-1.13)), less nicotine dependency measured by Lebanon Waterpipe Dependency Scale (aOR:0.90 (95%CI:0.85-0.96)), having history of quit attempt (aOR:2.14 (95%CI:1.16-3.96)), smoking restriction in the house (aOR:2.69 (95%CI:1.01-7.14)), and not sharing waterpipe with others (aOR:2.72 (95%CI:1.31-5.66)) predicted waterpipe smoking cessation.

CONCLUSIONS

In addition to nicotine dependency, social factors such as home restrictions on smoking, and not sharing waterpipe were identified as predictors of waterpipe smoking cessation. To help waterpipe smokers quit, social environment may be just as or even more important than well-known physical and psychological factors.

IMPLICATIONS

A range of factors, predominantly social factors play a significant role in facilitating or deterring waterpipe smokers from quitting smoking. Our findings suggest that interventions that focus on social as well as physical/psychological factors may encourage waterpipe smokers in achieving abstinence.

Smoking cessation medicines and e-cigarettes: a systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

Cigarette smoking is one of the leading causes of early death. Varenicline [Champix (UK), Pfizer Europe MA EEIG, Brussels, Belgium; or Chantix (USA), Pfizer Inc., Mission, KS, USA], bupropion (Zyban; GlaxoSmithKline, Brentford, UK) and nicotine replacement therapy are licensed aids for quitting smoking in the UK. Although not licensed, e-cigarettes may also be used in English smoking cessation services. Concerns have been raised about the safety of these medicines and e-cigarettes.

OBJECTIVES

To determine the clinical effectiveness, safety and cost-effectiveness of smoking cessation medicines and e-cigarettes.

DESIGN

Systematic reviews, network meta-analyses and cost-effectiveness analysis informed by the network meta-analysis results.

SETTING

Primary care practices, hospitals, clinics, universities, workplaces, nursing or residential homes.

PARTICIPANTS

Smokers aged ≥ 18 years of all ethnicities using UK-licensed smoking cessation therapies and/or e-cigarettes.

INTERVENTIONS

Varenicline, bupropion and nicotine replacement therapy as monotherapies and in combination treatments at standard, low or high dose, combination nicotine replacement therapy and e-cigarette monotherapies.

MAIN OUTCOME MEASURES

Effectiveness - continuous or sustained abstinence. Safety - serious adverse events, major adverse cardiovascular events and major adverse neuropsychiatric events.

DATA SOURCES

Ten databases, reference lists of relevant research articles and previous reviews. Searches were performed from inception until 16 March 2017 and updated on 19 February 2019.

REVIEW METHODS

Three reviewers screened the search results. Data were extracted and risk of bias was assessed by one reviewer and checked by the other reviewers. Network meta-analyses were conducted for effectiveness and safety outcomes. Cost-effectiveness was evaluated using an amended version of the Benefits of Smoking Cessation on Outcomes model.

RESULTS

Most monotherapies and combination treatments were more effective than placebo at achieving sustained abstinence. Varenicline standard plus nicotine replacement therapy standard (odds ratio 5.75, 95% credible interval 2.27 to 14.90) was ranked first for sustained abstinence, followed by e-cigarette low (odds ratio 3.22, 95% credible interval 0.97 to 12.60), although these estimates have high uncertainty. We found effect modification for counselling and dependence, with a higher proportion of smokers who received counselling achieving sustained abstinence than those who did not receive counselling, and higher odds of sustained abstinence among participants with higher average dependence scores. We found that bupropion standard increased odds of serious adverse events compared with placebo (odds ratio 1.27, 95% credible interval 1.04 to 1.58). There were no differences between interventions in terms of major adverse cardiovascular events. There was evidence of increased odds of major adverse neuropsychiatric events for smokers randomised to varenicline standard compared with those randomised to bupropion standard (odds ratio 1.43, 95% credible interval 1.02 to 2.09). There was a high level of uncertainty about the most cost-effective intervention, although all were cost-effective compared with nicotine replacement therapy low at the £20,000 per quality-adjusted life-year threshold. E-cigarette low appeared to be most cost-effective in the base case, followed by varenicline standard plus nicotine replacement therapy standard. When the impact of major adverse neuropsychiatric events was excluded, varenicline standard plus nicotine replacement therapy standard was most cost-effective, followed by varenicline low plus nicotine replacement therapy standard. When limited to licensed interventions in the UK, nicotine replacement therapy standard was most cost-effective, followed by varenicline standard.

LIMITATIONS

Comparisons between active interventions were informed almost exclusively by indirect evidence. Findings were imprecise because of the small numbers of adverse events identified.

CONCLUSIONS

Combined therapies of medicines are among the most clinically effective, safe and cost-effective treatment options for smokers. Although the combined therapy of nicotine replacement therapy and varenicline at standard doses was the most effective treatment, this is currently unlicensed for use in the UK.

FUTURE WORK

Researchers should examine the use of these treatments alongside counselling and continue investigating the long-term effectiveness and safety of e-cigarettes for smoking cessation compared with active interventions such as nicotine replacement therapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041302.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 59. See the NIHR Journals Library website for further project information.

Waterpipe smoking: a review of pulmonary and health effects

Waterpipe smoking is an old form of tobacco smoking, originating in Persia and the Middle East. The popularity of the waterpipe is increasing worldwide, particularly among young adults, and there are widespread misconceptions regarding its negative health effects. The inhaled smoke of the waterpipe contain several toxic and hazardous materials including nicotine, tar, polyaromatic hydrocarbons and heavy metals, all of which are proven to be related to lung diseases and cancer. Regular waterpipe smoking is associated with respiratory symptoms, a decrease in pulmonary function and increased risk for lung disease such as COPD. Additional negative health effects include increased risk for arterial stiffness, ischaemic heart disease and several cancer types including lung cancer. This review summarises the negative health effects of waterpipe smoking, with emphasis on cardiorespiratory complications. Increased awareness and knowledge amongst healthcare professionals will hopefully help identify waterpipe smokers and promote patient education. Applying World Health Organization (WHO) regulations will provide a synergistic effect in reducing waterpipe use and associated disease.

Cessation classification likelihood increases with higher expired-air carbon monoxide cutoffs: a meta-analysis

BACKGROUND

Expired-air carbon monoxide (CO) is commonly used to biochemically verify smoking status. The CO cutoff and CO monitor brand may affect the probability of classifying smokers as abstinent, thus influencing conclusions about the efficacy of cessation trials. No systematic reviews have tested this hypothesis. Therefore, we performed a meta-analysis examining whether the likelihood of smoking cessation classification varied due to CO cutoff and monitor brand.

METHODS

Eligible studies (k = 122) longitudinally assessed CO-verified cessation in adult smokers in randomized trials. Primary meta-regressions separately assessed differences in quit classification likelihood due to continuous and categorical CO cutoffs (Low, 3-4 parts per million [ppm]; [SRNT] Recommended, 5-6 ppm; Moderate, 7-8 ppm; and High, 9-10 ppm); exploratory analyses compared likelihood outcomes between monitor brands: Bedfont and Vitalograph.

RESULTS

The likelihood of quit classification increased 18% with each 1 ppm increase above the lowest cutoff (3 ppm). Odds of classification as quit significantly increased between each cutoff category and High: 261% increase from Low; 162% increase from Recommended; and 150% increase from Moderate. There were no differences in cessation classification between monitor brands.

CONCLUSIONS

As expected, higher CO cutoffs were associated with greater likelihood of cessation classification. The lack of CO monitor brand differences may have been due to model-level variance not able to be followed up in the present dataset. Researchers are advised to report outcomes using a range of cutoffs-including the recommended range (5-6 ppm)-and the CO monitor brand/model used. Using higher CO cutoffs significantly increases likelihood of quit classification, possibly artificially elevating treatment strategies.

Comparative efficacy and safety of pharmacological interventions for smoking cessation in healthy adults: A network meta-analysis

Smoking is the leading cause of morbidity and mortality in different non-communicable diseases, and cessation leads to immense health benefits. The present network meta-analysis has been conducted to evaluate and compare the effects of available pharmacological interventions for smoking cessation in adults. A standard meta-analysis protocol was developed and after performing a comprehensive literature search on MEDLINE/PubMed, Cochrane databases, and International Clinical Trials Registry Platform, reviewers extracted data from 97 randomized controlled trials. PRISMA guidelines were followed in data extraction, analysis and reporting of findings. Random effects Bayesian network meta-analysis was done to pool the effects across the interventions. Network graph was built, and for closed triangles in the network graph, node splitting analysis was performed. The primary outcome measure was self-reported biochemically verified smoking abstinence at six months. The number of participants achieving continuous abstinence was reported. Data for the number of participants reporting at least one adverse event was also extracted, if available. Combination of nicotine receptor agonist and nicotine replacement therapy had a significant odd of 4.4 (95%CrI:2.2-8.7), bupropion and nicotine receptor agonist 4.0 (95%CrI:2.1-7.7), bupropion and nicotine replacement therapy 3.8 (95%CrI:2.3-6.2), combination nicotine replacement therapy has an odd of 2.6 (95%CrI:1.8-3.8), and nicotine receptor agonist had a significant odd of 2.7 (95%CrI:2.3-3.2) when compared to placebo (moderate quality of evidence) for continuous abstinence at 6 months. When compared with behavioural therapy, the odds ratio of interventions was not statistically significant. Combination of nicotine receptor agonist and nicotine replacement therapy has the highest probability of being the best treatment for abstinence from smoking.