Adjustment of DOses of NIcotine in Smoking Cessation (ADONIS)

Smokers currently smoking at least 10 cigarettes per day with smoking related diseases are included. They are randomized either to receive standard nicotine replacement therapy (24 h nicotine patch 21, 14, 7 mg/day for one month each, respectively), control arm, or nicotine dose adjustment according their saliva cotinine: dose adaptation arm. In the control arm, at the discretion of the investigators, buccal forms of nicotine replacement therapies are allowed. In both arms, saliva cotinine determinations are performed every 2 weeks for 2 months. In the control arm saliva cotinine results are not communicated to the investigators. In the dose adaptation arm investigators receive saliva cotinine results and should adapt the nicotine doses (mg of nicotine/day) according to baseline (when smoking) saliva cotinine to obtain 100 % substitution. Smokers are assessed at weekly visits after the predetermined quit day for 3 months. Follow up at 6 months. Main outcome measure: sustained abstinence (self reported no smoking and expired air carbon monoxide concentration equal or less than 8 ppm during the last (3rd) month of the treatment phase.