Oral nicotine solution for smoking cessation: a pilot tolerability study.

This study was conducted to determine the preliminary tolerability of an oral nicotine solution with minimal behavioral intervention for smoking cessation. Twenty-five healthy volunteers who smoked at least 10 cigarettes per day and were motivated to quit smoking were enrolled in an open-labeled trial with a 12-week treatment and a 6-month follow-up period. After reviewing self-help materials and setting a quit-smoking day, subjects were provided nicotine solution to mix with their beverages to control smoking urges, and returned for refills eight times over 12 weeks. Abstinence (point prevalence) was defined as self-report of 0 cigarettes smoked for the previous 7 days verified by exhaled carbon monoxide (CO) <10 ppm. The oral nicotine solution was well tolerated when mixed with an individual's chosen beverage. Subjects controlled the concentration of nicotine consumed, which ranged from 0.25 to 10 mg nicotine base per 170-354 ml of beverage. One week after the quit date the mean venous nicotine level was 13.4 ng/ml and mean serum cotinine level was 418.0 ng/ml in six non-smokers. Abstinence rates at 4 weeks, 3 months, and 6 months were 28.0%, 24.0%, and 20.0%, respectively. It was concluded that an oral nicotine solution was tolerable and provided nicotine replacement at levels that may prove useful for smoking cessation. Further research to clarify appropriate dosages and optimal beverages for mixture, and controlled trials to assess safety and efficacy, appear in order.