Author ORCID Identifier

0000-0001-7794-1253

Defense Date

2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Healthcare Policy & Research

First Advisor

Andrew Barnes

Second Advisor

Thomas Eissenberg

Third Advisor

Caroline Cobb

Fourth Advisor

Robert Perera

Abstract

Heated Tobacco Products (HTPs) purport to expose people that use cigarettes to fewer of the harmful or potentially harmful constituents of tobacco while still delivering reinforcing amounts of nicotine (Auer, Concha-Lozano et al., 2017). An exemplar of the HTP class, IQOS, and its three varieties of “HeatSticks” have been authorized by the Food and Drug Administration (FDA) as “Modified Risk Tobacco Products” (MRTP). However, as the FDA is planning to ban menthol as a characterizing flavor in cigarettes, questions remain regarding whether characterizing flavors should be permitted in HTPs (FDA, 2022e). New evidence regarding HTP abuse liability (i.e., the likelihood that a tobacco product will produce and maintain dependence and long-term use) is needed now to inform regulatory action (Carter, Stitzer et al., 2009). This study aimed to measure the abuse liability of IQOS as a function of its available flavors (menthol and regular/tobacco) among adults that smoke menthol cigarettes across five dimensions: nicotine delivery, puff topography, self-reported effects (sometimes referred to as “subjective effects”), behavioral economic demand, and naturalistic use. Thirty adults that smoke menthol cigarettes completed a two-week, parallel group pilot clinical trial. During week 1, participants used their own brand (OB) menthol cigarettes in clinical laboratory sessions (Mon, Fri; two hours each day) and at home (Tues-Thurs). During week 2, participants were randomized to receive IQOS 2.4 with either Fresh Menthol (IQOS-M) HeatSticks or Tobacco/Regular (IQOS-T) HeatSticks to use in clinical laboratory sessions (Mon, Fri; two hours each day) and at home as a substitute for OB menthol cigarettes (Tues-Thurs). During each of the four clinical laboratory sessions, participants completed a 10-puff directed use bout with that week’s designated product. Each clinical laboratory visit involved measurement of the session product’s plasma nicotine delivery, puff topography, and self-reported effects as well as completion of a behavioral economic task known as the Experimental Tobacco Marketplace (ETM). Electronic daily-diary ecological momentary assessments (EMA) measured participant’s tobacco consumption while at home during the two-week study period. IQOS served as a stronger substitute for OB menthol cigarettes in the ETM task when Fresh Menthol HeatSticks were available for purchase compared to a “restricted market” that did not offer Fresh Menthol HeatSticks (p < 0.05). When participants were given IQOS products to use at home during week 2, the median participant in IQOS-M group reduced their daily cigarette consumption by 80% (relative to consumption during week 1) and the median participant in the IQOS-T by 37% (p < 0.05). Clinical laboratory results following acute self-administration procedures suggested that IQOS-M may suppress cravings for cigarettes (p < 0.10) as well as urges to smoke (p < 0.05) to a greater extent than IQOS-T among adults that use menthol cigarettes. Participants also reported enjoying the taste and overall flavor sensation associated with using IQOS-M more than IQOS-T (each p < 0.05). Differences in puff topography parameters and nicotine delivery across participants that used IQOS-M and participants that used IQOS-T in the clinical laboratory were relatively minor and not statistically significant (each p > 0.05). OB menthol cigarettes delivered more nicotine and were rated more favorably by participants with respect to flavor enjoyment, positive reinforcement, and negative reinforcement than either flavor of IQOS (each p < 0.05). Results of this investigation suggest that IQOS-M may have greater abuse liability and be a more compelling substitute for cigarettes than IQOS-T among people that use menthol cigarettes. The enhanced abuse liability of IQOS-M (relative to IQOS-T) among people that use menthol cigarettes might be the result of menthol-associated positive reinforcement or menthol’s possible role as a conditioned-stimulus of smoking behavior (Ahijevych & Garrett, 2010). Importantly though, OB menthol cigarettes appeared to have greater abuse liability than IQOS-M and IQOS-T, raising questions about whether IQOS could substitute for menthol cigarettes completely. This study contributes new evidence to the HTP literature that menthol flavor may increase HTP abuse liability but be insufficient to support complete substitution for people that smoke menthol cigarettes when both products are available. Tobacco regulatory policies that restrict access to menthol-flavored HTPs may reduce substitution with HTPs following a menthol cigarette ban but might promote attempts at complete smoking cessation in the post-ban period.

Comments

Please direct all questions to Augustus (Gus) White at whiteam25@vcu.edu.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

3-28-2024

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