Approximately one in five smokers who use nicotine replacement methods remains abstinent at one year. Although this is double the rate in smokers who do not use such aids, much remains to be learned about the optimal dosage and route of nicotine replacement therapy. Blondal and colleagues evaluated the short- and long-term abstinence rates in patients who used nicotine sprays in combination with patches in a placebo-controlled, double-blind trial.

In this Icelandic study, 237 smokers between 21 and 69 years of age were recruited through advertisements. To be included, they had to have a history of daily smoking for at least three years. Cardiac disease, alcohol abuse, pregnancy or lactation were grounds for exclusion. All participants attended an initial instructional meeting and four group meetings within the first three weeks of their quit dates.

Participants were randomly assigned by groups to receive either nicotine patch plus nicotine nasal spay or nicotine patch plus placebo spray. The patches provided 15 mg of nicotine for three months, followed by 10 mg for one month, then 5 mg for one month. The nicotine spray delivered 0.5 mg per dose and was packaged so that patients were unable to tell which therapy they had received.

Patients were assessed six weeks after stopping smoking and again at three, six, 12 and 72 months. Patients were finally checked after six years, and carbon monoxide levels were used to verify reported abstinence.

After six weeks, 51 percent of patients in the combined-therapy group had quit smoking, compared with 35 percent in the patch-only group. After six months, these figures were 31 and 16 percent, and after one year, 27 percent and 11 percent. After six years, one in six patients treated with combination therapy was abstinent, compared with one in 12 of those using only the patch.

The authors conclude that both short- and long-term abstinence rates are significantly improved by the use of combination therapy with a nicotine patch and spray compared with use of the patch alone. After the first year, few participants reported that they were still using the spray, indicating that the optimal time of spray use may not exceed one year.