Usefulness of markers in managing tobacco withdrawal.

To evaluate the usefulness of tobacco markers in dependent smokers being treated with transdermal nicotine patches, a study was conducted at the Tobacco Withdrawal Consultation Centre at the Hôpital Laennec, Paris, France. 125 patients were included in the study and, in a first time, carbon monoxide in exhaled air, carboxyhaemoglobin, urinary nicotine and cotinine, Fagerström index, were measured and correlated to the amount of nicotine inhaled per day. The most significant value was observed for cotinine. In a second time, 25 patients were followed clinically and biologically with urinary continine monitoring (group FC) and 73 were followed up only clinically (group FC). The success rate of therapy 12 weeks after the end of treatment was 72% in group FB and 28% in group FC. The nicotine patch dose was positively correlated (p < 0.01) with successful outcome. The lower the urinary cotinine level at 4 weeks, the more likely was successful outcome (p < 0.05). If psychological factors remain important, urinary cotinine monitoring in the course of nicotine patch treatment thus favours successful withdrawal.