CLINICAL OUTCOME OF SMOKING-CESSATION TRIAL OF NICOTINE CHEWING GUM EVALUATED BY ANALYSIS OF NICOTINE IN HAIR

The axial distribution of nicotine along the hair shafts was examined in 21 subjects enrolled in a placebo-controlled, double-blind trial of nicotine chewing gum (Nicorette) for validating their self-reported s moking behavior and their physicians' assessments. Hair samples obtain ed from the subjects once during the 3-month follow-up period (n = 10 for placebo and n = 11 for Nicorette ad libitum) were analyzed for the cm x cm distribution of nicotine along the hair shafts. Hair analysis results were compared with the monthly self-reports and with the plas ma concentrations of thiocyanate (SCN-) measured at 1-month intervals. A gradual decrease in nicotine content along the hair shafts generall y corresponded to the decrease in self-reported number of cigarettes s moked daily by the subjects who reported that they abstained from smok ing or decreased the number of daily cigarettes in placebo and nicotin e chewing gum groups. Because nicotine may dissociate slowly from hair follicle cells, nicotine in the hair did not mark a sudden decrease o r cessation of smoking and, therefore, hair analysis tended to underes timate the real decrease of smoking. However, physician assessment see med to depend solely on self-reporting because the time profile of cha nges in serum SCN- concentration did not correspond necessarily to the changes in the self-reported number of cigarettes used daily.