Aims To assess the influence of unsuccessful past quit attempts using pharmacological treatment on smoking cessation when using a new nicotine lozenge.
Design A double-blind, randomized, placebo-controlled trial.
Setting Fifteen sites in the United Kingdom and the United States.
Participants A total of 1818 smokers seeking smoking cessation treatment; 1145 had had previous pharmacological treatment with nicotine polacrilex lozenge.
Intervention Lozenge, 2 mg or 4 mg (or matched placebo); a higher dose was assigned to smokers who smoked their first cigarette of the day within 30 minutes, a sign of dependence. Smokers received minimal instruction and counseling.
Measurement Outcome was 28-day, CO-verified continuous abstinence at 6 weeks. Past use of medications was ascertained by self-report.
Findings Lozenge was efficacious among smokers with prior pharmacotherapy as well as among those without such history. The effect of lozenge (versus placebo) was significantly greater among those with previous treatment experience, because previous treatment was associated with significantly poorer outcome on placebo, and active lozenge treatment corrected this imbalance. Lozenge efficacy was similar whether smokers had previously tried patch or acute forms of nicotine replacement therapy (gum, inhaler and spray), and also similar for past use of Zyban (bupriopion).
Conclusions Smokers with a history of past failure of pharmacological treatment have lower success rates without pharmacological treatment, but equally good outcomes with active lozenge treatment. Smokers who previously tried pharmacological treatments but resumed smoking should be encouraged to try quitting again with the new nicotine lozenge.