Varenicline versus bupropion SR or placebo for smoking cessation: A pooled analysis
ABSTRACT To evaluate varenicline's efficacy for smoking cessation versus bupropion SR and placebo and to explore whether factors typically predictive of abstinence influence varenicline's efficacy versus placebo, as measured by the week 9-12 continuous abstinence rate (CAR9-12).
Smokers in 2 randomized, placebo-controlled trials received varenicline 1 mg BID (n=696), bupropion SR 150 mg BID (n=671), or placebo (n=685) for 12 weeks. Nontreatment followup lasted 40 weeks.
CAR(9-12) was greater for varenicline (44.0%) versus bupropion SR (29.7%; P<0.0001) and placebo (17.7%; P<0.0001). CAR(9-12) for varenicline versus placebo was not affected by age, gender, or nicotine dependence level.
Varenicline was more efficacious than bupropion SR or placebo. Varenicline's efficacy versus placebo was not influenced by factors predictive of abstinence.
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ABSTRACT: Tobacco smoking is one of the most preventable causes of morbidity and mortality, but current smoking cessation treatments have relatively poor long term efficacy. Anti-nicotine vaccines offer a novel mechanism of action whereby anti-nicotine antibodies (Ab) in circulation prevent nicotine from entering the brain, thus avoiding the reward mechanisms that underpin nicotine addiction. Since antibody responses are typically long lasting, such vaccines could potentially lead to better long-term smoking cessation outcomes. Clinical trials of anti-nicotine vaccines to date have not succeeded, although there was evidence that very high anti-nicotine Ab titers could lead to improved smoking cessation outcomes, suggesting that achieving higher titers in more subjects might result in better efficacy overall. In this study, we evaluated CpG (TLR9 agonist) and aluminum hydroxide (Al(OH)3) adjuvants with a model anti-nicotine antigen comprising trans-3'aminomethylnicotine (3'AmNic) conjugated to diphtheria toxoid (DT). Anti-nicotine Ab titers were significantly higher in both mice and non-human primates (NHP) when 3'AmNic-DT was administered with CpG/Al(OH)3 than with Al(OH)3 alone, and affinity was enhanced in mice. CpG also improved functional responses, as measured by nicotine brain levels in mice after intravenous administration of radiolabeled nicotine (30% versus 3% without CpG), or by nicotine binding capacity of NHP antisera (15-fold higher with CpG). Further improvement should focus on maximizing Ab function, which takes into account both titer and avidity, and this may require improved conjugate design in addition to adjuvants.International immunopharmacology 04/2013; 16(1). DOI:10.1016/j.intimp.2013.03.021 · 2.71 Impact Factor
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ABSTRACT: Existing trials of varenicline have typically excluded smokers with concurrent medical and psychiatric illnesses and no data exist comparing effectiveness of varenicline with combination pharmacotherapy. This study evaluated abstinence and psychiatric outcomes of various tobacco dependence medications, including varenicline. Retrospective cohort of 723 smokers, most with significant medical and psychiatric comorbidity, was evaluated at the UMDNJ-Tobacco Dependence Clinic from 2006 to 2008. Demographics, measures of tobacco dependence and co-morbidities, and a validated instrument measuring psychological distress (Kessler-6) were obtained. Primary outcome was 7-day point abstinence at 6 months after target quit date. Cessation medications used included combination pharmacotherapy (39%), single nicotine replacement therapy (NRT) or bupropion (29%), and varenicline (23%), with 9% using no medications. Overall, 23% of patients were abstinent at 6 months. In an adjusted regression model, smokers using varenicline or combination medications were more likely abstinent at 6 months than those using no medications (adjusted odds ratio=2.99; 95% confidence interval=1.20-7.47 and 2.80; 1.15-6.82, respectively), but not statistically higher than those using single medications (AOR=1.70). Age, gender, education, marital status, cigarettes per day, time to first cigarette, night smoking, and menthol smoking were not significantly related to abstinence. Varenicline or combination medications did not significantly increase serious psychological distress over the treatment period compared to other medication options. Both varenicline and combination pharmacotherapy were effective and did not increase psychological distress for up to 6 months in smokers with co-morbidities treated at a specialty clinic.Drug and alcohol dependence 10/2010; 114(1):77-81. DOI:10.1016/j.drugalcdep.2010.06.022 · 3.28 Impact Factor
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ABSTRACT: Varenicline, a partial agonist of alpha(4)beta(2) nicotinic acetylcholine receptors, is the most recently approved drug for smoking cessation. This paper reviews the outcomes of Phase 2 and Phase 3 clinical trials that assess the efficacy of varenicline in comparison to placebo and other smoking cessation pharmacotherapies, ie, sustained-release bupropion (bupropion SR) and nicotine transdermal patch. Varenicline has higher abstinence rates than placebo and the alternative active treatments at the end of standard regimen treatment periods. Significantly higher abstinence rates were also found with varenicline in comparison to both placebo and bupropion SR at the end of a 40-week non-treatment follow-up period. Varenicline typically tripled the abstinence rates compared with placebo. In addition, varenicline reduced craving and withdrawal symptoms as well as some of the positive experiences associated with smoking to a greater extent than placebo, bupropion SR, and nicotine replacement therapy (NRT). These findings are consistent with the proposed agonist/antagonist effects of varenicline. Preliminary studies assessing individual variables such as smoking dependency level and smoking reinforcement types provide justification to examine further the effects of varenicline according to these individual factors. Outcomes from such research could improve our understanding of varenicline's mechanism of action and could ultimately help clinicians to develop individualized smoking cessation programs. Also, given varenicline's ability to reduce the reward from smoking, it might be helpful to use it before cessation to motivate or prepare smokers for a quit attempt.Neuropsychiatric Disease and Treatment 05/2008; 4(2):353-63. · 2.15 Impact Factor