Acute electronic cigarette use: nicotine delivery and subjective effects in regular users

Rationale Electronic cigarettes are becoming increasingly popular among smokers worldwide. Commonly reported reasons for use include the following: to quit smoking, to avoid relapse, to reduce urge to smoke, or as a perceived lower-risk alternative to smoking. Few studies, however, have explored whether electronic cigarettes (e-cigarettes) deliver measurable levels of nicotine to the blood. Objective This study aims to explore in experienced users the effect of using an 18-mg/ml nicotine first-generation e-cigarette on blood nicotine, tobacco withdrawal symptoms, and urge to smoke. Methods Fourteen regular e-cigarette users (three females), who are abstinent from smoking and e-cigarette use for 12 h, each completed a 2.5 h testing session. Blood was sampled, and questionnaires were completed (tobacco-related withdrawal symptoms, urge to smoke, positive and negative subjective effects) at four stages: baseline, 10 puffs, 60 min of ad lib use and a 60-min rest period. Results Complete sets of blood were obtained from seven participants. Plasma nicotine concentration rose significantly from a mean of 0.74 ng/ml at baseline to 6.77 ng/ml 10 min after 10 puffs, reaching a mean maximum of 13.91 ng/ml by the end of the ad lib puffing period. Tobacco-related withdrawal symptoms and urge to smoke were significantly reduced; direct positive effects were strongly endorsed, and there was very low reporting of adverse effects. Conclusions These findings demonstrate reliable blood nicotine delivery after the acute use of this brand/model of e-cigarette in a sample of regular users. Future studies might usefully quantify nicotine delivery in relation to inhalation technique and the relationship with successful smoking cessation/harm reduction.

Self-titration by experienced e-cigarette users: blood nicotine delivery and subjective effects

Rationale Self-titration is well documented in the tobacco literature. The extent to which ecigarette users (vapers) self-titrate is unknown. Objective This study explored the effects of high and low nicotine strength liquid on puffing topography, nicotine delivery and subjective effects in experienced vapers. Methods Eleven experienced male vapers completed 60 minutes of ad libitum vaping under low (6 mg/mL) and high (24 mg/mL) nicotine liquid conditions in two separate sessions. Measurements included: puffing topography (puff number, puff duration, volume of liquid consumed); and changes in: plasma nicotine levels, craving, withdrawal symptoms, selfreported hit, satisfaction and adverse effects. Results Liquid consumption and puff number were higher, and puff duration longer, in the low nicotine strength condition (all ps < 0.01). The mean difference in nicotine boost from baseline in the low condition was 8.59 (7.52) ng/mL, 16.99 (11.72) ng/mL and 22.03 (16.19) ng/mL at 10, 30 and 60 minutes respectively. Corresponding values for the high condition were 33.77 (34.88) ng/mL, 35.48 (28.31) ng/mL and 43.57 (34.78) ng/mL (ps < 0.05). There were no statistically significant differences between conditions in self-reported craving, withdrawal symptoms, satisfaction, hit or adverse effects. Conclusions Vapers engaged in compensatory puffing with lower nicotine strength liquid, doubling their consumption. Whilst compensatory puffing was sufficient to reduce craving and withdrawal discomfort, self-titration was incomplete with significantly higher plasma nicotine levels in the high condition.

The placebo and nocebo effects on peak minute power during incremental arm crank ergometry

This investigation aimed to explore the effects of inert sugar-free drinks described as either ‘performance enhancing’ (placebo) or ‘fatigue inducing’ (nocebo) on peak minute power (PMP;W) during incremental arm crank ergometry (ACE). Twelve healthy, non-specifically trained individuals volunteered to take part. A single-blind randomised controlled trial with repeated measures was used to assess for differences in PMP;W, oxygen uptake, heart rate (HR), minute ventilation, respiratory exchange ratio (RER) and subjective reports of local ratings of perceived exertion (LRPE) and central ratings of perceived exertion (CRPE), between three separate, but identical ACE tests. Participants were required to drink either 500 ml of a ‘sports performance’ drink (placebo), a ‘fatigue-inducing’ drink (nocebo) or water prior to exercise. The placebo caused a significant increase in PMP;W, and a significant decrease in LRPE compared to the nocebo (p=0.01; p=0.001) and water trials (p=0.01). No significant differences in PMP;W between the nocebo and water were found. However, the nocebo drink did cause a significant increase in LRPE (p=0.01). These results suggest that the time has come to broaden our understanding of the placebo and nocebo effects and their potential to impact sports performance.

The placebo and nocebo effects on peak minute power during incremental arm crank ergometry

This investigation aimed to explore the effects of inert sugar-free drinks described as either ‘performance enhancing’ (placebo) or ‘fatigue inducing’ (nocebo) on peak minute power (PMP;W) during incremental arm crank ergometry (ACE). Twelve healthy, non-specifically trained individuals volunteered to take part. A single-blind randomised controlled trial with repeated measures was used to assess for differences in PMP;W, oxygen uptake, heart rate (HR), minute ventilation, respiratory exchange ratio (RER) and subjective reports of local ratings of perceived exertion (LRPE) and central ratings of perceived exertion (CRPE), between three separate, but identical ACE tests. Participants were required to drink either 500 ml of a ‘sports performance’ drink (placebo), a ‘fatigue-inducing’ drink (nocebo) or water prior to exercise. The placebo caused a significant increase in PMP;W, and a significant decrease in LRPE compared to the nocebo (p=0.01; p=0.001) and water trials (p=0.01). No significant differences in PMP;W between the nocebo and water were found. However, the nocebo drink did cause a significant increase in LRPE (p=0.01). These results suggest that the time has come to broaden our understanding of the placebo and nocebo effects and their potential to impact sports performance.

Assessing and Reporting the Adverse Effects of Antipsychotic Medication: A Systematic Review of Clinical Studies, and Prospective, Retrospective, and Cross-Sectional Research

Objective: Adverse effects (AEs) of antipsychotic medication have important implications for patients and prescribers in terms of wellbeing, treatment adherence and quality of life. This review summarises strategies for collecting and reporting AE data across a representative literature sample to ascertain their rigour and comprehensiveness. Methods: A PsycINFO search, following PRISMA Statement guidelines, was conducted in English-language journals (1980–July 2014) using the following search string: (antipsychotic* OR neuroleptic*) AND (subjective effect OR subjective experience OR subjective response OR subjective mental alterations OR subjective tolerability OR subjective wellbeing OR patient perspective OR self-rated effects OR adverse effects OR side-effects). Of 7,825 articles, 384 were retained that reported quantified results for AEs of typical or atypical antipsychotics amongst transdiagnostic adult, adolescent, and child populations. Information extracted included: types of AEs reported; how AEs were assessed; assessment duration; assessment of the global impact of antipsychotic consumption on wellbeing; and conflict of interest due to industry sponsorship. Results: Neurological, metabolic, and sedation-related cognitive effects were reported most systematically relative to affective, anticholinergic, autonomic, cutaneous, hormonal, miscellaneous, and non-sedative cognitive effects. The impact of AEs on patient wellbeing was poorly assessed. Cross-sectional and prospective research designs yielded more comprehensive data about AE severity and prevalence than clinical or observational retrospective studies. 3 Conclusions: AE detection and classification can be improved through the use of standardised assessment instruments and consideration of subjective patient impact. Observational research can supplement information from clinical trials to improve the ecological validity of AE data.

Investigating the effects of caffeine on executive functions using traditional Stroop and a new ecologically-valid virtual reality task, the Jansari assessment of Executive Functions (JEF©)

Objective: Caffeine has been shown to have effects on certain areas of cognition, but in executive functioning the research is limited and also inconsistent. One reason could be the need for a more sensitive measure to detect the effects of caffeine on executive function. This study used a new non-immersive virtual reality assessment of executive functions known as JEF© (the Jansari Assessment of Executive Function) alongside the ‘classic’ Stroop Colour- Word task to assess the effects of a normal dose of caffeinated coffee on executive function. Method: Using a double-blind, counterbalanced within participants procedure 43 participants were administered either a caffeinated or decaffeinated coffee and completed the ‘JEF©’ and Stroop tasks, as well as a subjective mood scale and blood pressure pre- and post condition on two separate occasions a week apart. JEF© yields measures for eight separate aspects of executive functions, in addition to a total average score. Results: Findings indicate that performance was significantly improved on the planning, creative thinking, event-, time- and action-based prospective memory, as well as total JEF© score following caffeinated coffee relative to the decaffeinated coffee. The caffeinated beverage significantly decreased reaction times on the Stroop task, but there was no effect on Stroop interference. Conclusion: The results provide further support for the effects of a caffeinated beverage on cognitive functioning. In particular, it has demonstrated the ability of JEF© to detect the effects of caffeine across a number of executive functioning constructs, which weren’t shown in the Stroop task, suggesting executive functioning improvements as a result of a ‘typical’ dose of caffeine may only be detected by the use of more real-world, ecologically valid tasks.