EFFECTIVENESS OF A TRANSDERMAL NICOTINE SYSTEM IN SMOKING CESSATION STUDIES

Abstract

To investigate the effectiveness and tolerability of a transdermal nicotine system (TNS) as an aid towards easing smoking cessation, two double-blind placebo-controlled randomized field studies were performed. The TNS was available in sizes of 10, 20 and 30 cm2, delivering 7, 14 and 21 mg of nicotine per 24 h. A first study was undertaken in general medical practice by a group of 21 doctors (Practitioner Study). This study involved 199 nicotine-dependent cigarette smokers of whom 100 were allocated to the nicotine group and 99 to the placebo group. The second trial was performed in 112 yound people, 56 in each treatment group, at the Universities of Basle and Zurich (University Study). The placebo and the nicotine groups were comparable in both studies. Participants smoking more than 20 cigarettes a day were treated with the 30-cm2 system and the others with the 20-cm2 system. When abstinence, as verified by CO measurements, was achieved, the next smaller system was applied. In the Practitioner Study, the double-blind treatment phase lasted for 12 weeks with consultations every month and in the University Study the consultations during the 9-weeks'' treatment period took place every 3 weeks. Abstainers in both studies will be followed up until 12 months after treatment was begun. After 1, 2 and 3 months of treatment 41%, 36% and 36% of the participants in the nicotine group of the Practitioner Study were abstinent. The corresponding figures in the placebo group were 19.4%, 20.4% and 22.5%. The differences were statistically significant for all three months (p = 0.001; p = 0.018 and p = 0.043). Body weight did not increase in the TNS group, but did in the placebo group (+ 4.4 kg). The craving for cigarettes and withdrawal symptoms decreased more under nicotine substitution. Abstinence rates in the University Study were initially higher with 51.8% in the nicotine group and 28.6% in the placebo group after 3 weeks of treatment, but then declined to 42.9% after 6 weeks and 39.3% after 9 weeks in the nicotine group and to 25% and 19.6%, respectively, in the placebo group. The differences between the groups were statistically significant on all 3 occasions, with p = 0.012, p = 0.046 and p = 0.023. Distinct but reversible local erythema, in some cases accompanied with edematous swelling of the skin, was observed in 7% of the participants in the nicotine group of the Practitioner Study and in 9% of those of the University Study. Altogether there were 9 drop-outs because of skin reactions in the two studies.