In addition to the three monotherapies, we tested two combination therapies. Research has generally supported the efficacy of NRT combinations. The 2008 PHS Guideline identified long-term (> 14 weeks) nicotine patch paired with either nicotine gum or nicotine nasal spray as efficacious relative to placebo and relative to the nicotine patch alone.1 A recent Cochrane meta-analysis also found that nicotine patch plus “fast acting” NRT was more effective than monotherapy.2 Combination NRT could be superior to monotherapy for several reasons. For instance, the uses of two NRT’s might produce more adequate nicotine replacement (i.e., higher blood nicotine levels 15) than a single NRT, although high-dose nicotine patches have not been shown to produce higher abstinence rates than standard-dose patches on a consistent basis.1, 2 Or, it is possible that each type of agent works through a different mechanism, so that having two types produces additive effects. The patch, for instance, produces a steady-state supply of nicotine to prevent severe nicotine withdrawal, and ad libitum NRT’s (gum, lozenge) provide a means for coping with situational challenges and transient urges to smoke.15, 16
