Authors' objectives:

The aim of this review was to assess the clinical effectiveness, cost-effectiveness and adverse effects of bupropion SR (Zyban (R)) and nicotine replacement therapy (NRT) for smoking cessation. The effects of therapy in assisting long-term reduction in the amount smoked by smokers who are unwilling or unable to quit were not assessed.

Authors' results and conclusions: Assessment of clinical effectiveness: The effectiveness of NRT as an aid to smoking cessation has been thoroughly investigated. The evidence indicates unequivocally that NRT as an aid to smoking cessation is more effective than placebo. The majority of the data come from studies investigating the use of NRT gum and NRT patches. Despite this, there are no data to indicate that other forms of NRT are less efficacious. There are no data to indicate sub-group differences in the response to NRT. There is clear evidence that bupropion SR is more effective than placebo. There is evidence from single subgroup populations that bupropion SR is as effective in smokers with chronic obstructive pulmonary disease, cardiovascular disease, and those who have failed in the past to achieve abstinence with bupropion SR, as in the general smoking population. Evidence to support the superiority of bupropion SR over NRT for smoking cessation is relatively weak, with one double-blind study indicating that the NRT patch is less effective than bupropion SR and another unblinded study finding no difference between NRT gum and bupropion SR. Further double-blind RCTs are required. Assessment of adverse events and safety: Overall, the incidence of adverse events with NRT is very low. The main concern relates to potential adverse cardiovascular effects (i.e. the same harmful effects that are the driving force behind needing to treat smoking as a chronic illness). There is strong evidence that the effects of nicotine acquired through NRT are no different from those of smoking-derived nicotine. Evidence suggests that the main problem with NRT is that its use can delay the reversal of the adverse effects of smoking normally associated with smoking cessation. There is evidence to suggest that the abuse potential of NRT is low. There is only very limited overlap of adverse symptoms associated with the different types of NRT. Thus, the qualitative differences of the adverse effects associated with the different types of NRT will determine their effectiveness in different individuals. None of the common adverse events of bupropion (rash and pruritus, irritability, insomnia, dry mouth, headache, tremor, urticaria) reported in this review are newly identified. The adverse events resulting in withdrawal from treatment with bupropion SR are the same as those for the IR formulation (skin disorders (mainly rash), insomnia, tremor, headache, dry mouth, anxiety), with the exception of motor disturbances, psychological problems, drowsiness, weight loss, headache/nasal congestion, thinking difficulties, dizziness and tachycardia/palpitations. Such differences might be due to differences in dose and duration of treatment, and differences in response between depressed and non-depressed patients. Significantly, the side-effect profile of bupropion SR does appear to be better than that of the IR formulation. This review identified seizure as the most significant and important potential adverse effect of bupropion SR, as had already been recognised. The crude incidence of seizure is lower with the SR than with the IR formulation; however, the evidence demonstrates that even in populations screened to exclude those at risk, seizures can occur. Significantly, no RCT of bupropion SR in smoking cessation has reported any seizures. This may be related to stricter screening in the clinical-trial setting than occurs in clinical practice.

Authors' recommendations: - Both NRT and bupropion SR are effective interventions to assist smoking cessation. - The relative effectiveness of bupropion SR and NRT still needs further research. - Information on how to maximise effectiveness in practice is still lacking, but motivational support is probably involved. - The most significant differences between NRT and bupropion SR relate to the adverse events and safety profiles of these interventions. - Overall, the safety profile of NRT is more favourable, particularly given the small but real risk of seizure with bupropion SR. - Irrespective of the methods used or the assumptions involved, the results of existing economic evaluations and the model developed in this review consistently suggest that smoking-cessation interventions, including the use of NRT and/or bupropion SR, re relatively cost-effective in terms of the cost per life-year saved. The worst-case scenarios still provide estimates of cost-effectiveness better than many other medical interventions.

Authors' methods: Systematic review and economic evaluation

Project Status: Completed

URL for project: http://www.hta.ac.uk/1239

Year Published: 2002

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: England, United Kingdom

Organisation Name: NIHR Health Technology Assessment programme

Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK

Contact Name: journals.library@nihr.ac.uk

Contact Email: journals.library@nihr.ac.uk

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