Aim: To investigate the efficacy of maintenance treatment with bupropion and/or nicotine gum for reducing smoking relapse.
Design, setting and participants: A 48-week study was conducted at a university-based smoking cessation clinic between February 2001 and October 2005. A total of 588 smokers received bupropion and nicotine patch in 8 weeks of open-label treatment (OLT); 289 abstainers during the last 4 weeks of OLT were randomized in double-blind placebo-controlled fashion to one of four arms for 16 weeks of maintenance treatment (MT) followed by 24 weeks of non-treatment follow-up (NTFU).
Intervention: Bupropion (300 mg/day) and 2 mg nicotine gum, used alone or combined, and comparable placebo pill and placebo gum. Behavioral counseling at all visits.
Outcome: Time to relapse (TTR) from randomization. Relapse is defined as the first 7 consecutive days of smoking. Abstinence verified by carbon monoxide <or= 8 parts per million.
Findings: TTR was longer with extended active treatments compared to placebo (median days to relapse: bupropion + placebo = 136, nicotine + placebo = 98, bupropion + nicotine = 90, double placebo = 71). Hazard ratios (HR) for relapse were statistically significant for bupropion + placebo versus double placebo during MT (HR = 0.59, 95% CI = 0.37-0.92) and to the end of NTFU (HR = 0.66, 95% CI = 0.42-0.96). However, bupropion's advantage dissipated upon stopping the drug. Gum use was low, preventing a valid assessment; but analysis restricted to gum users suggested a weak effect of extended nicotine gum.
Conclusion: Maintenance treatment with bupropion exerted a modest benefit for preventing smoking relapse; the optimum duration of bupropion treatment was unclear. Further research is needed to ascertain the merits of extended use of nicotine gum, other nicotine replacement agents and other treatments known to aid smokers for preventing relapse once abstinence is achieved.