Effect of immediate vs. gradual reduction in nicotine content of cigarettes on biomarkers of smoke exposure

Findings from a new study indicate that, for smokers, immediate reduction of nicotine in cigarettes resulted in much larger reductions in biomarkers of smoke exposure across time, compared with a gradual reduction or a control group.

Findings from a new study indicate that, for smokers, immediate reduction of nicotine in cigarettes resulted in much larger reductions in biomarkers of smoke exposure across time, compared with a gradual reduction or a control group. The double-blind, randomized, parallel-design study was conducted at 10 sites around the United States and included 1,250 daily smokers with no plans to stop smoking within 30 days. The study included 2 weeks of baseline smoking and 20 weeks of intervention: immediate reduction to 0.4 mg of nicotine per gram of tobacco cigarettes, gradual reduction from 15.5 mg to 0.4 mg of nicotine per gram of tobacco cigarettes with 5 monthly dose changes, or maintenance on 15.5 mg of nicotine per gram of tobacco cigarettes. The primary outcomes were between-group differences in three co-primary biomarkers of smoke toxicant exposure: breath carbon monoxide, urine 3-hydroxypropylmercapturic acid, and urine phenanthrene tetraol over the course of the intervention. When compared with the gradual reduction groups, the immediate reduction group had significantly lower levels of exposure for all three measures. In addition, significantly lower levels of exposure were seen in the immediate reduction group compared with the control group. While "immediate reduction was associated with lower toxicant exposure across time, smoking fewer [cigarettes per day], greater reduction in dependence, and more cigarette-free days," according to the authors, they also note "the immediate reduction in nicotine caused greater withdrawal symptoms, greater use of nonstudy cigarettes, and higher drop-out rates."