Objectives: To determine whether use of an oral nicotine inhaler can result in long term reduction in smoking and whether concomitant use of nicotine replacement and smoking is safe.
Design: Double blind, randomised, placebo controlled trial. Four month trial with a two year follow up.
Setting: Two university hospital pulmonary clinics in Switzerland.
Participants: 400 healthy volunteers, recruited through newspaper advertisements, willing to reduce their smoking but unable or unwilling to stop smoking immediately.
Intervention: Active or placebo inhaler as needed for up to 18 months, with participants encouraged to limit their smoking as much as possible.
Main outcome measures: Number of cigarettes smoked per day from week six to end point. Decrease verified by a measurement of exhaled carbon monoxide at each time point compared with measurement at baseline.
Results: At four months sustained reduction of smoking was achieved in 52 (26%) participants in the active group and 18 (9%) in the placebo group (P<0.001; Fisher's test). Corresponding figures after two years were 19 (9.5%) and 6 (3.0%) (P=0.012).
Conclusion: Nicotine inhalers effectively and safely achieved sustained reduction in smoking over 24 months. Reduction with or without nicotine substitution may be a feasible first step towards smoking cessation in people not able or not willing to stop abruptly.