Reduced-nicotine cigarettes decreased tobacco dependence and the number of cigarettes smoked, with very little evidence of withdrawal or compensatory smoking, in a preliminary study reported online Oct. 1 in the New England Journal of Medicine.
Moreover, study participants who smoked very-low-nicotine cigarettes for the 6-week study were twice as likely to report that they attempted to quit 1 month later, compared with participants who smoked their usual brand or control cigarettes that had the usual nicotine content.
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Reduced-nicotine cigarettes differ from “light” cigarettes in that the latter don’t actually reduce the nicotine content of the tobacco but instead increase ventilation of the cigarette – a strategy that is often circumvented by smokers who cover the ventilation holes or increase the number of cigarettes they smoke, said Eric C. Donny, Ph.D., of the department of psychology, University of Pittsburgh, and his associates.
The U.S. Food and Drug Administration recently was granted the authority to reduce, but not eliminate, nicotine in cigarettes if such action were deemed likely to benefit public health. However, no large-scale clinical trials have yet been performed to assess the potential benefit to public health.
Dr. Donny and his associates, supported by the National Institute on Drug Abuse and the FDA Center for Tobacco Products, conducted a double-blind, randomized trial at 10 sites comparing cigarettes with five levels of nicotine content among 839 adult smokers who were not planning to quit in the near future.
The study participants were assigned to smoke their usual brand of cigarettes (118 study subjects); control cigarettes containing the usual 15.8 mg of nicotine/g of tobacco (119 subjects); or experimental reduced-nicotine cigarettes containing 5.2 mg/g of nicotine (122 subjects), 2.4 mg/g (119 subjects), 1.3 mg/g (119 subjects), or 0.4 mg/g (242 subjects).
All the cigarettes were provided free of charge, and the smokers were paid for participating in the study. The dropout rate was only 8% at week 6 and did not differ significantly among the study groups.
The primary outcome – the average number of cigarettes smoked per day during week 6 – was markedly higher with the usual-brand group (22.2) and the control-cigarette group (21.3) than it was with the three lowest-nicotine groups (16.5, 16.3, and 14.9, respectively). That represents a reduction of 23%-30% in the number of cigarettes smoked in the latter three groups.
Tobacco dependence, as measured by the Wisconsin Inventory of Smoking Dependence Motives and the Fagerstrom Test for Nicotine Dependence, also was markedly lower with reduced-nicotine cigarettes.
Withdrawal symptoms did not increase; and during a brief voluntary abstinence period, smokers in the three lowest-nicotine groups actually reported fewer cravings than did those in the higher-nicotine groups, the investigators said (N Engl J Med. 2015 Oct 1;373[14]:1340-9).
At follow-up 30 days after completing the study, 34.7% of the participants who had smoked cigarettes with 0.4 mg/g of nicotine reported attempting to quit smoking, compared with 17% of those who had smoked cigarettes with 15.8 mg/g. In addition, participants who had smoked cigarettes with 1.3 mg/g or 0.4 mg/g of nicotine were still smoking significantly fewer cigarettes per day, even though the study had ended.
“In summary, these data suggest that if nicotine content is adequately reduced, smokers may benefit by smoking fewer cigarettes and experiencing less nicotine dependence, with few negative consequences,” Dr. Donny and his associates wrote. “If confirmed in longer-term studies, these findings suggest that, when combined with other tobacco-control policies (e.g., taxation and expanded access to treatment), limiting the nicotine content of cigarettes ... could improve public health.”
The study authors added that a longer clinical trial is now underway to further assess reduced-nicotine cigarettes.
NIDA and the FDA Center for Tobacco Products supported the study. Dr. Donny reported having no relevant financial disclosures. Two of his associates reported ties to Pfizer, and two reported serving as expert witnesses regarding addiction litigation against tobacco companies.