Nicotine pharmacokinetics and subjective responses after using nicotine pouches with different nicotine levels compared to combustible cigarettes and moist smokeless tobacco in adult tobacco users

The Potential Impact of Oral Nicotine Pouches on Public Health: A Scoping Review

INTRODUCTION

Oral nicotine pouches (ONPs) are a new class of nicotine products. This scoping review summarizes evidence on ONPs and explores their potential public health impact.

AIMS AND METHODS

We conducted a structured literature search for empirical studies across three electronic databases through January 10, 2024. Outcomes included ONP product characteristics, use patterns, beliefs and perceptions, toxicity, and marketing and sales.

RESULTS

Sixty-two studies were included, 17 were industry-funded. Most studies were from the United States. While large variations across studies were observed in ONP youth prevalence estimates, nationally representative U.S. studies find current use at 1.5% and lifetime use below 2.5% through 2023. Between 35% and 42% of U.S. adolescents and young adults have heard of ONPs, and 9-21% of tobacco-naïve youth were susceptible to trying them. U.S. adult-use estimates varied widely (0.8%-3% current; 3%-16% lifetime use) and were limited to populations with a history of tobacco use. The chemical composition of ONPs suggests fewer harmful/potentially harmful compounds at lower levels than cigarettes and smokeless tobacco (SLT), except formaldehyde. Industry-funded studies find substantially less cytotoxicity compared to cigarettes and suggest that higher nicotine-strength ONPs can deliver nicotine at levels comparable to or higher than SLT or cigarettes, although with slower nicotine release than cigarettes. Evidence on the cytotoxicity of ONPs relative to SLT is mixed.

CONCLUSIONS

ONPs appear to be less toxic than cigarettes and deliver comparable nicotine, presenting an alternative for combustible product users, although key data are mainly available from industry-funded studies. Data from independent research is critically needed. Industry marketing of ONPs may encourage initiation in youth and situational and dual use in adults.

IMPLICATIONS

The review provides an initial assessment of the potential role of ONPs in harm reduction and aims to determine unintended consequences of their use (youth uptake and dual-use) and identify populations that disproportionately use the product. This information is essential for tobacco regulatory bodies in determining the net public health impact of nicotine pouches.

Small pouches, but high nicotine doses-nicotine delivery and acute effects after use of tobacco-free nicotine pouches

Tobacco-free nicotine pouches are new nicotine products for oral consumption. They can contain very high nicotine amounts that have not been addressed with clinical studies yet. Thus, nicotine delivery, effects on craving, and side effects were assessed using pouches with up to 30 mg nicotine. In this single-center, five-arm, crossover study, 15 regular cigarette smokers consumed tobacco-free nicotine pouches from different brands with 6, 20, and 30 mg for 20 min. Comparators were nicotine-free pouches and tobacco cigarettes. At baseline and predefined time points over a study period of 240 min, plasma nicotine concentrations, effects on cigarette craving, and side effects were assessed. Cardiovascular parameters including arterial stiffness were measured using a MobilOGraph. Consumption of 30 mg nicotine pouches has led to a higher nicotine uptake compared with the cigarette (Cmax: 29.4 vs 15.2 ng/mL; AUC: 45.7 vs 22.1 ng/mL × h). Nicotine uptake in the acute phase was rapid during use of the 30 mg pouch and cigarette. Extraction rate of nicotine differed between pouches. Use of all products has reduced acute cigarette craving, even the nicotine-free pouch. During consumption of the cigarette and the pouches with 20 and 30 mg, heart rate increased about 27, 12, and 25 bpm, respectively. Parameters for arterial stiffness were elevated and all pouches have induced mouth irritations. The pouches with 30 mg nicotine had overall the strongest side effects and may induce addiction. As craving was also reduced by products with less nicotine, it is questionable whether such high nicotine contents should be allowed on the market. A limit of nicotine content is warranted. The nicotine release rate varies across products and needs to be known to estimate the nicotine delivery.

Using pod based e-cigarettes and nicotine pouches to reduce harm for adults with low socioeconomic status who smoke: A pilot randomized controlled trial

INTRODUCTION

Alternative Nicotine Delivery Systems (ANDS) such as e-cigarettes (EC) and oral nicotine pouches (ONP) may facilitate the substitution of smoking for those unwilling to quit. This pilot study assesses the harm reduction potential of EC and ONP among smokers with low socioeconomic status (SES).

METHODS

Adults who smoked daily in the past 6 months, had a household income < 250% federal poverty level and had no intention of quitting smoking in the next 30 days were randomized 2:2:1 to 8 Weeks of 5% nicotine EC; 4mg ONP or assessment-only control (CC). The primary outcome was a within-group change in cigarettes per day (CPD) from Baseline to Week 8.

RESULTS

45 individuals were randomized (EC: N=18; ONP: N=18; CC: N=9). Analyses included 33 participants who completed the Week 8 visit. Mean age was 50.2 years (SD:10.7) and average CPD at baseline was 13.9 (SD: 10.1). For those randomized to EC, average CPD decreased from 14.7 (95%CI: 10.3; 19.1) at Baseline to 2.9 (95%CI: 0.09; 5.79) at Week 8 (p-value <0.001). For those randomized to ONP, average CPD decreased from 15.0 (95%CI: 5.02; 24.93) to 8.3 (95%CI: 1.34; 15.18) by Week 8 (p-value =0.01). In the EC and ONP groups, respectively, 4 (28.6%) and 1 (8.3%) participant fully switched from smoking to the ANDS product by Week 8.

CONCLUSIONS

Individuals with low SES who smoke had lower CPD after switching to EC or ONP. These findings show the potential of ANDS in helping smokers switch to less harmful devices.

IMPLICATIONS

This study provides novel evidence that e-cigarettes and nicotine pouches can be a harm reduction tool for individuals with lower SES who smoke and are not willing to quit smoking, contributing to reducing tobacco-related disparities in this population.

Evaluating the effects of nicotine concentration on the appeal and nicotine delivery of oral nicotine pouches among rural and Appalachian adults who smoke cigarettes: A randomized cross-over study

BACKGROUND AND AIMS

Oral nicotine pouches (ONPs) probably offer reduced harm compared with cigarettes, but independent data concerning their misuse liability are lacking. We compared nicotine delivery and craving relief from ONPs with different nicotine concentrations to cigarettes.

DESIGN

This was a single-blind, three-visit (≥ 48-hour washout), randomized-cross-over study. Participants were encouraged to complete all study visits in less than 1 month.

SETTING

The study took place in Rural/Appalachian Ohio.

PARTICIPANTS

Participants comprised 30 adults who smoke cigarettes. Participants (meanage  = 34.5) were 60% men and 90% White.

INTERVENTION

Participants who were ≥ 12-hour tobacco-abstinent used: (1) a 3-mg nicotine concentration ONP, (2) a 6-mg nicotine concentration ONP and (3) usual brand cigarette in separate visits. ONPs (wintergreen Zyn) were used for 30 minutes; cigarettes were puffed every 30 sec for 5 minutes.

MEASUREMENTS

Plasma nicotine and self-reported craving were assessed at t = 0, 5, 15, 30, 60 and 90 minutes. The primary outcome was plasma nicotine concentration at t = 30 minutes. A secondary outcome was craving relief at t = 5 minutes.

FINDINGS

At t = 30, mean [95% confidence interval (CI)] plasma nicotine was 9.5 ng/ml (95% CI = 7.1, 11.9 ng/ml) for the 3 mg nicotine ONP, 17.5 ng/ml (95% CI = 13.7, 21.3) for the 6 mg nicotine ONP and 11.4 ng/ml (95% CI = 9.2, 13.6 ng/ml) for the cigarette. Mean plasma nicotine at t = 30 minutes differed between the 3- and 6-mg nicotine ONPs (P = 0.001) and between the 6-mg nicotine ONP and cigarette (P = 0.002). Mean (95% CI) craving at t = 5 minutes was lower for the cigarette (mean = 1.00, 95% CI = 0.61, 1.39) than either the 3 mg (mean = 2.25, 95% CI = 1.68, 2.82; P < 0.0001) or 6 mg nicotine (mean = 2.19, 95% CI = 1.60, 2.79; P < 0.0001) ONP.

CONCLUSIONS

Among adult smokers, using 6-mg nicotine concentration oral nicotine pouches (ONPs) was associated with greater plasma nicotine delivery at 30 minutes than 3-mg ONPs or cigarettes, but neither ONP relieved craving symptoms at 5 minutes as strongly as a cigarette. Accelerating the speed of nicotine delivery in ONPs might increase their misuse liability relative to cigarettes.

Tobacco-Free Nicotine Pouches and Their Potential Contribution to Tobacco Harm Reduction: A Scoping Review

Tobacco harm reduction (THR) refers to strategies designed to reduce the health risks associated with tobacco smoking but may involve continued use of nicotine and/or tobacco. Next-generation products (NGPs) are a THR alternative as they do not burn tobacco or produce smoke and deliver nicotine and have fewer and substantially lower levels of harmful chemicals compared to cigarettes. Tobacco‑free nicotine pouches (TFNPs) are an emerging category of nicotine‑containing oral products that do not combust or contain tobacco leaf. Similar to Swedish snus, TFNPs are placed between a user's lip and gum, and nicotine is absorbed through the oral mucosa rather than being inhaled. The aim of this scoping review was to systematically collate and evaluate published scientific evidence (cut‑off of 31 May 2023) identified from bibliometric databases investigating the potential of TFNPs to contribute to THR. Overall, studies examining chemical constituents indicated that the use of TFNPs may result in lower exposure to toxicants than other tobacco or nicotine-containing products, both combustible and non‑combustible. This reduction in toxicant exposure has been demonstrated by multiple human biomarker studies and in vitro toxicological assessments to translate to harm reduction potential in smokers switching to TFNPs. However, further study is warranted. At present, there is some evidence from human behavioral research that TFNPs can support either transitioning away from smoking or reducing cigarette consumption. Furthermore, TFNP use appears very much limited to current users of traditional tobacco products, and youth uptake has been limited. In conclusion, the findings of this review indicate that TFNPs have the potential to support THR efforts and may help inform evidence‑based regulation.

A Randomized, Controlled Study to Assess Changes in Biomarkers of Exposures Among Adults Who Smoke That Switch to Oral Nicotine Pouch Products Relative to Continuing Smoking or Stopping All Tobacco Use

The purpose of this open-label, randomized, controlled, in-clinic, 5-parallel-group study was to assess biomarkers of exposure (BoE) to select harmful and potentially harmful constituents in adults who smoke (N = 144) switching to oral tobacco products (on!® mint nicotine pouches; test products) compared to continuing smoking cigarettes (CS) and completely quitting all tobacco products (NT). Changes in 20 BoE to select harmful and potentially harmful constituents, including 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), were evaluated. Adult smokers smoked their usual brand of cigarettes for 2 days (baseline assessments) and then were randomly assigned to ad libitum use of 2, 4, or 8 mg test products, CS, or NT for 7 days. Analysis of covariance was used to assess the Day 7 BoE levels between each group using test products, CS, and NT. The creatinine-adjusted total urinary NNAL and other 18 of 19 BoE levels (except nicotine equivalents [NEs]) were significantly lower (P < .05) on Day 7, among all test product groups compared to CS. Geometric least-square means were reduced for all biomarkers of exposure, except NEs, in test product groups by approximately 42%-96% compared to the CS group, and reductions were comparable to the NT group. The geometric least-square means for urinary NE between the test product and the CS groups, although not significantly different, the Day 7 mean change relative to the CS group were 49.9%, 65.8%, and 101% for the 2, 4, and 8 mg test product groups, respectively. The substantial reduction in harmful and potentially harmful constituent exposure suggests complete switching from cigarettes to test products may present a harm reduction opportunity for adults who smoke.

Harmful and potentially harmful constituents (HPHCs) in two novel nicotine pouch products in comparison with regular smokeless tobacco products and pharmaceutical nicotine replacement therapy products (NRTs)

BACKGROUND

Tobacco-free nicotine pouches is a novel category of oral nicotine-delivery products. Among current tobacco users such pouches may serve as a low-risk alternative to cigarettes or conventional, tobacco-based oral products e.g., snus and moist snuff. In the United States (U.S.), the market leading nicotine-pouch brand is ZYN®. However, no data on the chemical characteristics of ZYN have been published.

METHODS

We screened for 43 compounds potentially present in tobacco products in seven oral nicotine-delivery products: ZYN (dry and moist), snus (General^®), moist snuff (CRP2.1 and Grizzly Pouches Wintergreen), and two pharmaceutical, nicotine replacement therapy products (NRTs, Nicorette^® lozenge and Nicotinell^® gum). Thirty-six of the tested compounds are classified as harmful and potentially harmful constituents (HPHCs) by the Center for Tobacco Products at the U.S. Food and Drug Administration (FDA-CTP). Five additional compounds were included to cover the GOTHIATEK^® product standard for Swedish snus and the last two compounds were chosen to include the four primary tobacco specific nitrosamines (TSNAs).

RESULTS

The tested products contained nicotine at varying levels. The two ZYN products contained no nitrosamines or polycyclic aromatic hydrocarbons (PAHs) but low levels of ammonia, chromium, formaldehyde, and nickel. In the NRT products we quantified low levels of acetaldehyde, ammonia, cadmium, chromium, lead, nickel, uranium-235, and uranium-238. The largest number (27) and generally the highest levels of HPHCs were quantified in the moist snuff products. For example, they contained six out of seven tested PAHs, and seven out of ten nitrosamines (including NNN and NNK). A total of 19 compounds, none of which were PAHs, were quantified at low levels in the snus product. NNN and NNK levels were five to 12-fold lower in snus compared to the moist snuff products.

CONCLUSIONS

No nitrosamines or PAHs were quantified in the ZYN and NRT products. Overall, the number of quantified HPHCs were similar between ZYN and NRT products and found at low levels.

Emerging Oral Nicotine Products and Periodontal Diseases

Oral nicotine pouches are emerging as a new "modern oral" nicotine product. These prefilled pouches contain nicotine, flavorings, and filling agents that dissolve in the mouth. Nicotine can be derived from tobacco leaf or chemical synthesis. Traces of TSNAs and toxic chromium were detected in the pouch products. This raises the concern about general and periodontal health. This review aims to update the current oral nicotine products research relating to periodontal disease and its relevance in periodontal inflammation. Nicotine interacts with host cells and affects inflammatory responses to microbial challenges. It may directly or indirectly deteriorate periodontal tissues by activating nicotinic acetylcholine receptors, repressing PDL fibroblasts cells, increasing cellular ROS and cytokines/chemokines, growth factors, breaking microbiota balance, and dysregulating miRNAs expression. Studies show that appealing flavorings contained in nicotine pouches pose harm to periodontal innate immune responses and increase penetration of nitrosamines. In addition, flavored ONPs increase the risk of dual or poly-tobacco products among young adults, stacking up detrimental effects on the periodontium. Given the recent growth of users, further studies are needed to elucidate the impact of ONPs, even poly-tobacco use, on systemic and periodontal health. Moreover, policymakers should ensure to avoid generating a new wave of nicotine addiction among youths in the U.S.