Objective: To compare the combination of a nicotine inhaler and bupropion to either treatment alone for initiating smoking abstinence and relapse prevention.
Methods: Smokers were randomized to receive a nicotine inhaler, bupropion, or both for 3 months. At 3 months, smoking-abstinent study participants were randomized to their initial medications or placebo. Participants who were smoking at 3 months were randomized to an alternative treatment regimen or placebo. This study was conducted from July 2001 to January 2003.
Results: A total of 1700 smokers were randomized to treatment (phase 1) for 3 months. Among the 941 study participants eligible for randomization to the phase 2 trial, 837 continued in the study. For the phase 2 trial, 405 smoking-abstinent participants were randomized to relapse prevention for 9 additional months, and 432 smokers were randomized to re-treatment for an additional 3 months. At the end of the initial 3 months of treatment (phase 1), 82 (14%) of 566, 145 (26%) of 567, and 194 (34%) of 567 study participants receiving a nicotine inhaler, bupropion, or both, respectively, were abstinent from smoking. Of the 405 smoking-abstinent participants at the end of 3 months, the bupropion group had more smokers than the placebo group (mean No. of smokers, 1.5 vs 1.1; P < .001), and the nicotine inhaler group had higher smoking abstinence rates at 12 months than the placebo group. Those receiving combination therapy had reduced rates of relapse to smoking for the first 3 months of relapse prevention, but this difference disappeared after the initial 3 months. Of the 432 study participants who were smoking at the end of 3 months and who received an alternative treatment regimen, the 223 smokers initially assigned to a nicotine inhaler were more likely to stop smoking at 6 months if they were re-treated with bupropion instead of placebo (8 [7%] of 111 vs 0 [0%] of 112; P = .003), and the 209 smokers initially treated with bupropion and re-treated with a nicotine inhaler did not have significantly higher smoking abstinence rates (6 [6%] of 104 vs 3 [3%] of 105; P = -.50).
Conclusion: Combined therapy with a nicotine inhaler and bupropion increased smoking abstinence rates. Continuation of the initial combination therapy does not appear to prevent relapse to smoking. Timing of re-treatment and alternative approaches to relapse prevention should be further examined.