Nicotine elimination and tolerance in non-dependent cigarette smokers

Abstract

Although most smokers are nicotine-dependent, recent studies suggest that some very light smokers ("chippers", who smoke fewer than five cigarettes per day) may smoke for decades without developing dependence. It was considered that slowed nicotine elimination and/or reduced nicotine tolerance might underlie chippers' ability to maintain smoking at such low levels. To evaluate this hypothesis, we studied the elimination kinetics and pharmacodynamics of nicotine in chippers and matched regular smokers. Plasma nicotine levels and cardiovascular responses were observed for several hours after subjects were administered uniform doses of tobacco smoke. Chippers did show less chronic nicotine tolerance, but only on some response measures. Their rates of nicotine elimination equaled those of regular smokers. This finding, when coupled with other data about chippers' smoking patterns and nicotine absorption, establish that chippers cannot maintain substantial plasma nicotine levels between cigarettes, and thus suggest that attempts to maintain minimal trough levels of nicotine do not underlie chippers' smoking.

How should we define light or intermittent smoking? Does it matter?

“…Public health will need to consider, in light of these factors, whether a categorization of LITS is warranted. et al (1996) , Gilpin et al (1997) , Wellman et al (2006) Average ≤ 5 Shiffman (1989) , Shiffman et al ( 1990Shiffman et al ( , 1992, , 1 -5…”

“…Very light smoking is defi ned fairly consistently as daily smoking of fewer than 5 CPD ( Shiffman et al, 1992 ), 1 -4 CPD ( Rosengren et al, 1992 ), or fewer than 6 CPD ( Hajek, West, & Wilson, 1995 ;Shiffman, 1989 ).…”

“…The defi nition of chipper has included relatively consistent consumption levels of fewer than 5 CPD, no more than 5 CPD, and 1 -5 CPD, but most defi nitions include additional qualifi ers (e.g., on 2 or more [or 4 or more] days per week, more than weekly, never more than 10 CPD, duration at the level specifi ed for at least 2 years, or never exceeding this consumption for more than a few months; Brauer, Hatsukami, Hanson, & Shiffman, 1996 ;Gilpin, Cavin, & Pierce, 1997 ;Presson, Chassin, & Sherman, 2002 ;Sayette, Martin, Werz, Shiffman, & Perrott, 2001 ;Shiffman, 1989 ;Shiffman, Fischer, Zettler-Segal, & Benowitz, 1990 ;Shiffman et al, 1992 ;Wellman, DiFranza, & Wood, 2006 ).…”

Craving-Induced EEG Reactivity in Smokers: Effects of Mood Induction, Nicotine Dependence and Gender

“…A secondary objective of this research was to begin to explore individual differences in mood-moderated craving. As severity of nicotine dependence has been shown to moderate cue-induced brain activity [10] , the study will include comparisons between regular and light smokers ('chippers'), the latter smokers smoking fewer than five cigarettes per day on average [56,57] . Cravings are elicited by smoking cues in chippers [58] , but appear to be less intense than those observed in regular smokers, and are not affected by smoking abstinence [59] .…”

Genetic susceptibility to substance dependence

“…16 The difference between chippers and regular smokers does not appear to be due to different rates of elimination of nicotine, as regular smokers and chippers inhale the same amount of cigarette smoke, absorb equal amounts of nicotine, and eliminate nicotine at equal rates. 14,17,18 The difference is also not attributable to the age at which individuals began smoking, because there was no difference in the age at which chippers and regular smokers started to smoke. 13,17 Finally, it has been hypothesized that chippers might find the initial effects of smoking highly aversive and therefore do not progress to become regular smokers.…”