Cigarette smokers' concurrent use of smokeless tobacco: dual use patterns and nicotine exposure.

BACKGROUND: The concurrent use of cigarettes with other tobacco products, such as smokeless tobacco (SLT), is increasingly common. Extant work with cigarette smokers who also use SLT is based heavily on retrospective reports and between-group comparisons. The purpose of this study was to assess prospectively the patterns of dual users' product use and nicotine exposure on days when cigarettes were smoked exclusively (single use) versus concurrently with SLT (dual use). DESIGN: Forty-six dual cigarette-SLT users recorded their product use in real time via ecological momentary assessment for a 2-week longitudinal design. They responded to questions about situational factors (eg, location, mood) using this same diary, and collected saliva samples each night for later cotinine measurement. At the end of this 2-week period, users reported on their reasons for and beliefs about SLT use. RESULTS: Cotinine levels were significantly higher on dual versus single use days (mean±SEM=374.48±41.08 ng/mL vs 300.17±28.13 ng/mL, respectively; p<0.01), and the number of cigarettes logged was higher on dual versus single use days (11.13±0.98 vs 9.13±1.11, respectively; p<0.01). Product use was distinguished by situational factors, with the strongest predictor being location of use. Moreover, the most common reason for initiating (56.52%) and continuing (67.39%) SLT use was to circumvent indoor smoking restrictions. CONCLUSIONS: Results support the idea of product supplementation rather than replacement among this convenience sample of dual users. For smokers whose primary motivation for SLT use involves situations where they would otherwise be tobacco free, the potential benefits of clean indoor air laws may be diminished.

Assessing pharmacy-based naloxone access using an innovative purchase trial methodology.

OBJECTIVES: Massachusetts was among the first states to allow standing orders to facilitate pharmacy-based naloxone purchases and reduce opioid overdose deaths. We conducted a unique purchase trial to establish a valid measure of standing order naloxone in Massachusetts, using purchasers from 2 high priority populations to determine whether naloxone is less accessible to those who use illicit opioids than other potential purchasers. DESIGN: Purchase trial. SETTING AND PARTICIPANTS: The study used a stratified random sample of 200 chain and independent retail pharmacies across Massachusetts. Each pharmacy underwent 2 purchase attempts-1 by a person who used illicit opioids (PWUIO) and 1 by a potential bystander who did not use illicit opioids but had a relationship with someone at risk of opioid overdose. OUTCOME MEASURE: Successful or unsuccessful naloxone purchase attempt. RESULTS: Overall, 322 of 397 purchase attempts (81%) were successful, with no statistically significant difference between PWUIO and bystanders (P = 0.221). Most purchases (93%) resulted in the acquisition of single-step nasal naloxone (Narcan; median cost $133.38). Forty percent of the purchases included state-mandated verbal counseling, and PWUIO were significantly less likely to receive counseling than bystanders (30% vs. 51%, P < 0.001). Common reasons for failed purchase were not stocking naloxone (47%), price > $150 (25%), and requiring a prescription (15%). Chain pharmacies were significantly more likely to sell naloxone than independent pharmacies (86% vs. 53%, P < 0.001). CONCLUSION: We documented high levels of naloxone access for both PWUIO and bystanders, suggesting Massachusetts could serve as a model for states seeking to improve pharmacy-based naloxone access. Additional implementation efforts should focus on expanding availability at independent pharmacies and supporting pharmacies in proactively offering naloxone to PWUIO and other high-risk individuals.

Unilateral parietal brain injury increases risk-taking on a rat gambling task.

Traumatic brain injury (TBI) affects millions of individuals every year. Many of these injuries lead to lasting effects, particularly impairments in domains broadly classified as executive functions, such as impulse control and decision-making. While these impairments have been historically associated with frontal brain damage, other injuries such as concussion or parietal injury also contribute to similar dysfunction. However, it is unknown whether animal models of TBI would replicate these broad effects that are observed in human patients. In the current study, we delivered a unilateral parietal controlled cortical impact injury and assessed the performance of rats on a motoric task (rotarod) and a test of decision-making and impulsivity (rodent gambling task). TBI rats demonstrated significant motor impairments on the rotarod task; however, this did not extend to difficulties inhibiting motor actions (impulsivity). In addition, TBI caused chronic alterations to risk-based decision-making, extending out to 12 weeks post-injury. Specifically, rats with TBI preferred the riskiest, and most suboptimal option over all others. The current data suggest that models of unilateral TBI are sufficient for replicating some aspects of executive dysfunction (risky decision-making), while others are limited to frontal damage (impulsivity). These models may be used to develop therapeutics targeted at the chronic post-injury period when these symptoms often manifest in patients, a critically understudied area in preclinical TBI research.

Personality and impulsivity as predictors of tobacco use among emerging adults: A latent class analysis.

The tobacco industry markets their products toward emerging adults (18-29), with the goal of increasing use among this age group. To inform prevention efforts, researchers are investigating how specific demographic and psychological traits may predict tobacco initiation and continuation. Participants were 578 incoming university freshmen from the Appalachian region. Participants provided information on demographics, personality traits, impulsivity characteristics, lifetime use of cigarettes and electronic cigarettes (ECIGs), and current use of cigarettes, ECIGs, small cigars/cigarillos, large cigars, smokeless tobacco, and waterpipe. Latent class analysis identified tobacco-use classes and regressions identified psychological predictors of class membership. Participants were Nonusers, Experimenters, and Polytobacco Users. Lower agreeableness and conscientiousness as well as higher extraversion and neuroticism were associated with being Experimenters or Polytobacco Users. Lower impulsivity was associated with being Nonusers. Distinct types of emerging adults belong to each tobacco use class, suggesting that individual differences be incorporated in prevention efforts.

Differential effects of d-amphetamine and atomoxetine on risk-based decision making of Lewis and Fischer 344 rats.

Individuals with attention-deficit/hyperactivity disorder tend to make risker choices during probabilistic-discounting procedures. Thus, how common attention-deficit/hyperactivity disorder medications affect probabilistic discounting is of interest. In general, d-amphetamine increases risk-taking while atomoxetine has produced mixed effects in rats. Results from previous studies may result from genetic factors. Lewis and F344 rats have neurochemical differences that may be relevant to probabilistic discounting and how drugs affect such behavior. In this study, we evaluated dose-dependent effects of d-amphetamine and atomoxetine on probabilistic discounting of Lewis and F344. Male Lewis and F344 chose between one food pellet delivered 100% of the time and three food pellets delivered following decreasing probabilities of delivery (i.e. 100%, 66.7%, 33.3%, 16.5%, and 8.25%). Saline, d-amphetamine (0.1-1.8 mg/kg), and atomoxetine (0.1-7.8 mg/kg) were tested acutely. Lewis and F344 did not differ in choice at baseline. d-Amphetamine increased risky choice for both rat strains at low-to-moderate doses, although it did so at a lower dose (0.1 and 0.3 mg/kg) for F344 as compared to Lewis (0.3 mg/kg only). At high doses (1.0 and 1.8 mg/kg), d-amphetamine disrupted choice, increased frequencies of omitted trials, and reduced reinforcer sensitivity. Although atomoxetine increased frequencies of omitted trials at high doses (5.6 and 7.8 mg/kg), it had no effect on probabilistic discounting for either rat strain. Although Lewis and F344 differ in various types of impulsivity (i.e. motor, choice), with Lewis being the more impulsive of the two, the present results suggest that Lewis and F344 do not differ in risk-based decision-making. Effects of d-amphetamine on probabilistic discounting may be biology-dependent and differ from effects of atomoxetine.

Piloting a clinical laboratory method to evaluate the influence of potential modified risk tobacco products on smokers' quit-related motivation, choice, and behavior.

Research methods are needed that can predict whether the availability of potential modified risk tobacco products (MRTPs) may influence smokers' quit-related motivation, choice, and behavior. This pilot study assessed the primary outcomes of feasibility and adherence to address this need using an electronic cigarette (ECIG) as a model MRTP. Cigarette smokers were randomly assigned to use only their own brand of cigarettes (OB-only) or a second-generation ECIG (18 ng/ml nicotine) plus their OB cigarettes (ECIG+OB) ad libitum for four weeks. Participants logged products using a mobile device, collected used cigarette filters, and provided saliva samples every day for analysis of cotinine. They returned to the lab once per week to provide a breath sample and accept or decline a choice to quit all tobacco products (i.e., cigarettes and/or ECIGs). They also returned for a one-month follow-up visit. Of those participants randomized (n = 60), 56.7% completed the 4-week intervention and 40.0% completed the follow-up visit. The primary reason for withdrawal was poor adherence with mobile device use. Comparable numbers of participants in each group chose to make a quit attempt, although more OB-only participants chose to quit during the first two weeks and more ECIG+OB participants during the last two weeks. With protocol modifications to reduce participation burden, the current method might ultimately be used by regulators to predict how smokers' quit-related motivation, choice, and behavior are influenced by current and future MRTPs.

Contingency tracking during unsignaled delayed reinforcement: Effects of delay duration and d-amphetamine.

In two experiments, the role of the response-reinforcer relation in maintaining low-rate responding under unsignaled delay conditions was investigated. In both experiments pecking by pigeons on one response key, denoted the relevant key, was reinforced under an unsignaled delay-of-reinforcement procedure (defined as tandem variable-interval (VI) differential-reinforcement-of-other behavior [DRO] schedule). Responding on a second key, denoted the irrelevant key, had no programmed consequences. Between sessions, the location of the relevant key varied (after one, two, or three sessions) pseudorandomly. In Experiment 1, the delay (DRO) duration was manipulated parametrically. Overall, proportional relevant-key response rates (relevant-key response rates / [relevant-key response rates + irrelevant key response rates]) increased across 3-session sequences in which the relevant key remained in the same location and decreased as the DRO duration was changed systematically (2, 5, and 10 s). In Experiment 2, acute administration of d-amphetamine increased proportional relevant-key response rates during 1-day sequences for only the DRO 5-s duration, and results over 3-day sequences, once a discrimination had already been established, were inconsistent. Results support that the response-reinforcer relation is the primary determinant of responding, and such discriminations are relatively resistant to disruption or potentiation by behaviorally active doses of d-amphetamine.