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171 result(s) for "McEwan, Michael"
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A randomised study to assess the nicotine pharmacokinetics of an oral nicotine pouch and two nicotine replacement therapy products
Nicotine replacement therapies (NRTs) are intended for short-term use to help cigarette smokers to quit. Some smokers find NRTs ineffective or seek a more satisfactory source of nicotine. Tobacco-free oral nicotine pouch (NP) products have emerged as a potential reduced risk product compared with cigarettes and other tobacco products. In a randomised crossover clinical study, thirty-four healthy adult smokers were enrolled and their nicotine C max and AUC 0-T determined for three 4 mg nicotine products (NP, gum, lozenge) under fasting conditions. The NP, lozenge and gum mean C max values were 8.5, 8.3 and 4.4 ng/mL, AUC 0-T values were 30.6, 31.5 and 14.3 ng*h/mL, respectively. The NP showed similar nicotine bioavailability to the lozenge ( p  = 0.6526 (C max ), p  = 1.0000 (AUC 0-T )), and superior bioavailability to the gum ( p   < 0.0001 for C max and AUC 0-T ). Compared with the lozenge, the NP demonstrated greater product satisfaction with a higher number of positive responses to subjective satisfaction questions. All products were judged to be well-tolerated; the incidence of minor adverse events was lower for the NP (18.2%) than the lozenge (33.3%) or gum (18.8%). In summary, NPs may provide smokers with a more satisfying alternative nicotine source as compared to the reference NRTs. Study Registry/Registered Trial No: ISRCTN/ISRCTN65708311.
Changes in Biomarkers of Exposure on Switching From a Conventional Cigarette to the glo Tobacco Heating Product: A Randomized, Controlled Ambulatory Study
Abstract Introduction Tobacco heating products (THPs) generate lower machine yields of toxicants compared to those found in conventional cigarette smoke. During use, these products are likely to expose users to lower levels of particulate matter and harmful and potentially harmful compounds compared with smoking cigarettes. Aims and Methods This randomized, controlled study is investigating whether biomarkers of exposure (BoE) to smoke toxicants are reduced when smokers switch from smoking cigarettes to using the glo THP in a naturalistic, ambulatory setting. Control groups include smokers who are abstaining from cigarette smoking and never-smokers. At a baseline study visit, 24-hour urine samples and spot blood samples were taken for BoE analysis, and exhaled carbon monoxide was also measured. N-(2-cyanoethyl) valine (CEVal) was used as a marker of compliance in subjects asked to refrain from combustible cigarette smoking. Subjects are being followed up at periodic intervals for 360 days; this article presents data following a planned interim analysis at day 90. Results In continuing smokers, BoE remained stable between baseline (day 1) and day 90. In both per-protocol and CEVal-compliant analysis populations, reductions in BoE were observed in subjects switching to using glo or undergoing smoking cessation. These reductions were statistically significant for a number of BoE when switching to glo was compared with continued smoking. Furthermore, in both populations, reductions observed in subjects switching to using glo were comparable to those seen with smoking cessation and were also to levels similar to those seen in never-smokers. Conclusion glo is a reduced-exposure tobacco product. Implications This clinical study builds on a previous 5-day confinement study and demonstrates that when smokers switched from smoking combustible cigarettes to using the glo THP in a naturalistic, ambulatory setting, their exposure to tobacco smoke toxicants was significantly decreased. For most BoE examined, this was to the same extent as that seen when a control group of smokers ceased cigarette smoking, or even to levels seen in never-smoker controls. This indicates that glo is a reduced-exposure product with the potential to be a reduced-risk tobacco product, when used by smokers whose cigarette consumption is displaced completely. Clinical trial registration ISRCTN81075760.
A randomised controlled single-centre open-label pharmacokinetic study to examine various approaches of nicotine delivery using electronic cigarettes
Smokers who switch completely to e-cigarettes may reduce their relative risk of tobacco-related disease. Effective nicotine delivery from e-cigarettes is important in consumer acceptance. We assessed whether protonated nicotine and e-cigarette devices delivering greater aerosol mass increase nicotine delivery and product liking. A randomised controlled non-blinded eight-arm crossover study was used to assess plasma nicotine pharmacokinetics and product liking for two e-cigarettes (Vype ePen3 and Vype ePen) with various nicotine e-liquid formulations and a conventional cigarette among 24 healthy dual-users of cigarettes and e-cigarettes. Product use and puff count were also assessed. Results show that nicotine bioavailability was greater for Vype ePen3 with greater aerosol mass delivery than for Vype ePen (C max , p  = 0.0073; AUC 0–120 min , p  = 0.0102). Protonated nicotine (18 mg/mL, medium protonation) e-liquid yielded higher nicotine bioavailability than unprotonated nicotine (18 mg/mL) e-liquid (C max , p  = 0.0001; AUC 0–120 min , p  = 0.0026). There was no significant difference in T max between e-liquids. Nicotine bioavailability did not differ between nicotine benzoate formulation (30 mg/mL nicotine, high protonation) and combustible cigarettes (C max , p  = 0.79; AUC 0–120 min , p  = 0.13). Vype ePen3 with protonated nicotine delivers nicotine more efficiently with the potential to increase product liking relative to earlier devices using unprotonated e-liquid.
Assessing the impact of protonating acid combinations in e-cigarette liquids: a randomised, crossover study on nicotine pharmacokinetics
The addition of protonating acids to e-cigarette liquid formulations (e-liquids) enhances nicotine bioavailability in e-cigarette use. However, little is known about the impact of different combinations of protonating acid on nicotine pharmacokinetics. The objectives of this study were to compare pharmacokinetics of nicotine absorption following use of a closed-system e-cigarette, containing e-liquids with two different nicotine levels and with different ratios of three common protonating acids—lactic, benzoic and levulinic. In a randomised, controlled, crossover study, nicotine pharmacokinetics and product liking were assessed for prototype e-liquids used in a Vuse e-cigarette containing either 3.5% or 5% nicotine and varying ratios of lactic, benzoic and/or levulinic acid. During an 8-day confinement period, 32 healthy adult current cigarette smokers/e-cigarette dual users used a single study e-liquid each day during 10-min fixed and ad libitum use periods after overnight nicotine abstinence. For most comparisons, C max and AUC 0–60 following both fixed and ad libitum puffing were significantly higher for e-liquids containing 5% nicotine compared with 3.5% nicotine. However, C max and AUC 0–60 were not statistically different for 5% nicotine e-liquids containing varying ratios of lactic, levulinic and benzoic acid when compared to an e-liquid containing lactic acid only. Mean scores for product liking were similar for all e-liquid formulations assessed, regardless of nicotine concentration, acid content, and whether the product was used in a fixed or ad libitum puffing regimen. While e-liquid nicotine concentration significantly affected users’ nicotine uptake, the different combinations of benzoic, levulinic and lactic acid in the e-liquids assessed had limited impact on nicotine pharmacokinetics and product liking scores.
An abuse liability assessment of the glo tobacco heating product in comparison to combustible cigarettes and nicotine replacement therapy
Tobacco heating products (THPs) have reduced emissions of toxicants compared with cigarette smoke, and as they expose user to lower levels than smoking, have for a role to play in tobacco harm reduction. One key concern of Public Health is that new tobacco and nicotine products should not be more addictive than cigarettes. To assess their abuse liability, we determined nicotine pharmacokinetics and subjective effects of two THPs compared with conventional cigarettes and a nicotine replacement therapy (Nicotine inhaler). In a randomised, controlled, open-label, crossover study healthy adult smokers used a different study product in a 5 min ad libitum use session in each of four study periods. Product liking, overall intent to use again, urge for product and urge to smoke questionnaires were utilised to assess subjective effects. Nicotine uptake was greater for the cigarette (C max  = 22.7 ng/mL) than for either THP (8.6 and 10.5 ng/mL) and the NRT (2.3 ng/mL). Median T max was significantly longer for the NRT (15.03 min) than for the tobacco products (4.05–6.03 min). Product liking and overall intent to use again was highest for the cigarette, and higher for the THPs than the NRT. Urge to smoke was reduced more by the cigarette than by the other three products. Urge to use the THPs was greater than the NRT. These findings suggest that the abuse liability of the THPs lies between that of subjects usual brand cigarettes and the NRT.
A novel clinical method to measure skin staining reveals activation of skin damage pathways by cigarette smoke
Background Long‐term use of cigarettes can result in localised staining and aging of smokers’ skin. The use of tobacco heating products (THPs) and electronic cigarettes (ECs) has grown on a global scale; however, the long‐term effect of these products’ aerosols on consumers’ skin is unknown. This pilot clinical study aimed to determine whether THP or EC aerosol exposure results in skin staining or activation of biomarkers associated with oxidative stress. Materials and methods Eight areas were identified on the backs of 10 subjects. Two areas were used for air control, and two areas exposed to 32‐puffs of cigarette smoke (CS), THP or EC aerosols, which were delivered to the skin using a 3‐cm diameter exposure chamber and smoke engine. Skin colour was measured using a Chromameter. Squalene (SQ), SQ monohydroperoxide (SQOOH) and malondialdehyde (MDA) levels were measured in sebum samples by mass spectrometry and catalase colorimetry. Results CS exposure significantly increased skin staining, SQOOH and MDA levels and SQOOH/SQ ratio. THP and EC values were significantly lower than CS; EC values being comparable to air control. THP values were comparable to EC and air control at all endpoints, apart from skin staining. SQ and catalase levels did not change with exposure. Conclusions CS stained skin and activated pathways known to be associated with skin damage. THPs and ECs produced significantly lower values, suggesting they could offer hygiene and cosmetic benefits for consumers who switch exclusively from smoking cigarettes. Further studies are required to assess longer‐term effects of ECs and THPs on skin function.
Modelling the nicotine pharmacokinetic profile for e-cigarettes using real time monitoring of consumers’ physiological measurements and mouth level exposure
Pharmacokinetic (PK) studies can provide essential information on abuse liability of nicotine and tobacco products but are intrusive and must be conducted in a clinical environment. The objective of the study was to explore whether changes in plasma nicotine levels following use of an e-cigarette can be predicted from real time monitoring of physiological parameters and mouth level exposure (MLE) to nicotine before, during, and after e-cigarette vaping, using wearable devices. Such an approach would allow an -effective pre-screening process, reducing the number of clinical studies, reducing the number of products to be tested and the number of blood draws required in a clinical PK study Establishing such a prediction model might facilitate the longitudinal collection of data on product use and nicotine expression among consumers using nicotine products in their normal environments, thereby reducing the need for intrusive clinical studies while generating PK data related to product use in the real world. An exploratory machine learning model was developed to predict changes in plasma nicotine levels following the use of an e-cigarette; from real time monitoring of physiological parameters and MLE to nicotine before, during, and after e-cigarette vaping. This preliminary study identified key parameters, such as heart rate (HR), heart rate variability (HRV), and physiological stress (PS) that may act as predictors for an individual’s plasma nicotine response (PK curve). Relative to baseline measurements (per participant), HR showed a significant increase for nicotine containing e-liquids and was consistent across sessions (intra-participant). Imputing missing values and training the model on all data resulted in 57% improvement from the original’learning’ data and achieved a median validation R 2 of 0.70. The study is in its exploratory phase, with limitations including a small and non-diverse sample size and reliance on data from a single e-cigarette product. These findings necessitate further research for validation and to enhance the model's generalisability and applicability in real-world settings. This study serves as a foundational step towards developing non-intrusive PK models for nicotine product use.
Understanding the effectiveness and underlying mechanisms of lifestyle modification interventions in adults with learning disabilities: protocol for a mixed-methods systematic review
Background Adults with learning disabilities have an increased disposition to unhealthy lifestyle behaviours which often occur simultaneously. Existing studies focus on complex interventions targeting unhealthy diet, physical inactivity, sedentary behaviour, smoking, and alcohol use to reduce health risks experienced. It is essential to understand how well these interventions work, what works, for whom, in what context and why. This study aims to investigate the effectiveness and underlying mechanisms of lifestyle modification interventions for adults with learning disabilities. Methods This is a mixed-methods systematic review consisting of a network meta-analysis (NMA) and realist synthesis. Electronic databases (ASSIA, CINAHL, EMBASE, MEDLINE, and PsycINFO) will be searched from inception to 14 January 2021 with no language restriction. Additionally, trial registries, grey literature databases and references lists will be searched. Studies related to lifestyle modification interventions on the adult population (>18 years) with learning disabilities will be eligible for inclusion. Two independent researchers will screen studies, extract data and assess its quality and risk of bias using the Cochrane Collaboration’s Risk of Bias Assessment Tool (RoB Version 2) and ROBINS-I. The strength of the body of evidence will be assessed based on the GRADE approach. The NMA will incorporate results from RCTs and quasi-experimental studies to estimate the effectiveness of various lifestyle interventions. Where appropriate, a component NMA (CNMA) will be used to estimate effectiveness. The realist synthesis will complement and explain the findings of NMA and CNMA by including additional qualitative and mixed-methods studies. Studies will be included based on their relevance to the programme theory and the rigour of their methods, as determined by quality appraisal tools appropriate to the study design. Results from both syntheses will be incorporated into a logic model. Discussion The paucity of population-specific lifestyle interventions contributes to the challenges of behaviour change in adults with learning disabilities. This study will provide an evidence-base from which various stakeholders can develop effective interventions for adults with learning disabilities. The evidence will also help prioritise and inform research recommendations for future primary research so that people with learning disabilities live happier, healthier and longer lives. Trial registration PROSPERO CRD 42020223290
Plasma Nicotine Pharmacokinetics of Oral Nicotine Pouches Across Varying Flavours and Nicotine Content
In recent years several nicotine products have been introduced that aim to offer smokers an alternative to cigarettes. As well as having fewer toxicants than combustible cigarettes, such nicotine products must be able to deliver nicotine efficiently. The aim of this study was to determine and compare the pharmacokinetics of nicotine absorption from nine oral tobacco-free smokeless nicotine pouches with varying nicotine content and flavours.In a randomised, open-labelled, controlled, crossover clinical study, nicotine pharmacokinetics and product-liking were compared between nine nicotine pouches (Velo, BAT; 4- or 7-mg nicotine per pouch and in eight flavours). During a 10-day confinement period, 42 healthy adult participants, who were current smokers of combustible cigarettes, used a single study product once each day during a 45-min use period following overnight nicotine abstinence.Maximum plasma nicotine concentration and area under curve for nicotine concentration versus time 180 min after the start of study product use were significantly greater for the 7-mg than for the 4-mg Velo pouches (p < 0.0001). These values did not differ between flavours among the 7-mg Velo nicotine pouches after adjustment for multiple comparisons (both p > 0.003). The median time to maximum plasma nicotine concentrations and mean product-liking scores were similar regardless of nicotine content and flavour.Regardless of flavour, nicotine pouches with the same nicotine content and formulation produce similar pharmacokinetic parameters and can deliver nicotine efficiently. Nicotine pouches could be a satisfying alternative for smokers switching from conventional cigarettes. [Contrib. Tob. Nicotine Res. 32 (2023) 130–139]