Characterizing the relationship between increases in the cost of nicotine and decreases in nicotine content in adult male rats: implications for tobacco regulation

Abstract

BACKGROUND A large reduction in the nicotine content of cigarettes may benefit public health by reducing the rate and the prevalence of smoking. A behavioral economics framework suggests that a decrease in nicotine content may be considered an increase in the unit price of nicotine (unit price = reinforcer cost / reinforcer magnitude). Increasing the price of cigarettes (i.e., increasing reinforcer cost) would be considered an equivalent change in unit price to reducing nicotine content (i.e., reducing reinforcer magnitude). OBJECTIVES The goal of the present experiments was to characterize the relationship between increases in nicotine cost and decreases in nicotine dose. MATERIALS AND METHODS A rat self-administration model was used to assess this relationship across three experiments, with an emphasis on very low nicotine doses to model a potential nicotine reduction policy. Cost was manipulated via changes in the number of responses required to earn an infusion. RESULTS Results show that increases in the cost of nicotine and decreases in nicotine content were not equivalent manipulations. Nicotine consumption was more sensitive to nicotine dose than to nicotine cost. Nicotine consumption was also not equivalent across a variety of cost and dose combinations forming a single unit price. CONCLUSIONS Results of the present studies suggest that nicotine reduction is likely to have a large impact on nicotine exposure from cigarettes.

Rats choose high doses of nicotine in order to compensate for changes in its price and availability

“…Hence, nicotine preference should shift to the highest dose because it represents the best value (lowest unit price), just as it did in the present study (see also Smith et al . ().…”

Status and future directions of preclinical behavioral pharmacology in tobacco regulatory science.

“…The use of behavioral economic methods to assess the abuse liability of drugs and the effectiveness of interventions and public policies was originally proposed by Hursh (Hursh, 1984, 1991) over 25 years ago. However, although clinical researchers often use this approach to study tobacco abuse liability (Bickel, Marsch, & Carroll, 2000; DeGrandpre, Bickel, Higgins, & Hughes, 1994; Johnson & Bickel, 2003; Shahan, Bickel, Madden, & Badger, 1999; Tidey, Cassidy, Miller, & Smith, 2016), preclinical research has only recently begun to use this paradigm to address tobacco regulatory issues (Grebenstein, Burroughs, Roiko et al, 2015, 2013; Smith, Rupprecht, Sved, & Donny, 2016b). Extending behavioral economics to tobacco addiction research in nonhumans is important because it provides a common conceptual and methodological framework to facilitate translation between preclinical studies, clinical trials, epidemiological studies, and public policy concerned with tobacco regulation.…”