Symptoms of nicotine toxicity in subjects achieving high cotinine levels during nicotine replacement therapy.

INTRODUCTION: Nicotine replacement therapy (NRT) aids smoking reduction and cessation. Although NRT is effective and safe, some smokers may achieve high nicotine levels. The purpose of this study was to determine the incidence and severity of nicotine-related adverse events in subjects with levels of cotinine, a metabolite of nicotine, that increased by >50% compared with baseline smoking in controlled clinical trials of NRT. METHODS: Data from participants in randomized, double-blind, controlled trials of various formulations of NRT (Nicorette®), including patch, gum, oral inhaler, sublingual tablet, nasal spray, mouth spray, and combinations, were extracted from a clinical database. Eligible studies were performed between 1989 and 2010. In addition to baseline, at least 1 subsequent plasma or salivary cotinine concentration was measured, and adverse events were recorded simultaneously. Of 28 eligible studies, 24 were smoking cessation studies and 4 were smoking reduction studies. RESULTS: Cotinine levels that increased by >50% above baseline were recorded during treatment in 746 of 7,120 subjects (10.5%). Nausea was reported in 16 subjects (0.2% of the total, upper 99% confidence limit [CL] 0.4%), vomiting in 2 subjects (0.0%, upper 99% CL 0.1%), palpitations in 5 subjects (0.1%, upper 99% CL 0.2%), dizziness in 11 subjects (0.2%; upper 99% CL 0.3%), and headache in 35 subjects (0.5%, upper 99% CL 0.7%). CONCLUSIONS: Typical symptoms indicating nicotine overdose together with high cotinine levels were rare during treatment with NRT. These findings support the safety of NRT for smoking cessation or reduction.

Nicotine Population Pharmacokinetics in Healthy Smokers After Intravenous, Oral, Buccal and Transdermal Administration.

BACKGROUND: In 4 decades, numerous nicotine replacement therapy products have been developed. Population pharmacokinetic models can support exposure-response modeling and inform nicotine replacement therapy product development, but only limited model-based cross-study population pharmacokinetic analyses for nicotine replacement therapy products have been published. OBJECTIVES: The aim of this retrospective analysis was to assess the population pharmacokinetics of nicotine across intravenous, oral, transdermal and oromucosal (mouth spray, chewing gum, lozenge and inhaler) routes and formulations in healthy smoking subjects. METHODS: Data on 930 unique subjects (46,016 observations) from 29 single- and repeated-dose studies with multiple formulations across intravenous, oral, transdermal and oromucosal routes of administration were included. Data from intravenous and extravascular routes of administration were modelled separately for run efficiency reasons. For developing extravascular models, clearance and disposition parameters and their inter-individual variabilities were fixed to the estimates for intravenously delivered nicotine. Detectable pre-dose nicotine concentrations were modelled as a hypothetical nicotine bolus into the central compartment at the start of wash-out. Modelling repeated-dose oral and buccal administrations required a time-dependent increase in clearance or decrease in bioavailability to describe the data adequately. RESULTS: Disposition of intravenous nicotine was best described by a three-compartment model with initial and terminal half-lives of 7 min and 4.5 h, respectively, and the absorption of single oral doses was best described with a first-order absorption rate constant of 1.55 h-1. The data of buccal formulations were modelled with parallel oromucosal absorption and gastrointestinal absorption of a part of the dose that is swallowed. For transdermal nicotine, parallel zero- and first-order release from the patch and a transit-compartment absorption model best described the data. Key pharmacokinetic parameters were reliably estimated, with typical values for clearance (67 L/h for a 70-kg subject), volume of distribution (4.3 L/kg), oral bioavailability (40%) and transdermal bioavailability (76%) within expected ranges. The estimated fraction of the dose swallowed for buccal formulations ranged from 55% (gum) to 69% (lozenge). CONCLUSIONS: Robust population pharmacokinetic models were developed for five nicotine replacement therapy product types and for intravenous and oral nicotine. These population pharmacokinetic models are used in exposure-response analyses and simulation-based nicotine replacement therapy product design.

A Time-to-Event Model Relating Integrated Craving to Risk of Smoking Relapse Across Different Nicotine Replacement Therapy Formulations.

Smoking increases the risk of cancer and other diseases, causing an estimated 7 million deaths per year. Nicotine replacement therapy (NRT) reduces craving for smoking, therefore, increasing an individual's probability to remain abstinent. In this work, we for the first time quantitatively described the relationship between craving and smoking abstinence, using retrospectively collected data from 19 studies, including 3 NRT formulations (inhaler, mouth spray, and patch) and a combination of inhaler and patch. Smokers motivated to quit were included in the NRT or placebo arms. Integrated craving (i.e., craving over a period of time) was assessed with 4-category, 5-category, or 100-mm visual analogue scale. The bounded integer model was used to assess latent craving from all scales. A time-to-event model linked predicted integrated craving to the hazard of smoking relapse. Available data included 9,323 adult subjects, observed for 3 weeks up to 2 years. At the study end, 9% (11% for NRT and 5% for placebo), on average, remained abstinent according to the protocol definition. A Gompertz-Makeham hazard best described the data, with a hazard of smoking relapse decreasing over time. Latent integrated craving was positively related to the hazard of smoking relapse, through a sigmoidal maximum effect function. For the same craving, being on NRT was found to reduce the hazard of relapse by an additional 30% compared with placebo. This work confirmed that low craving is associated with a high probability of remaining smoking abstinent and that NRT, in addition to reducing craving, increases the probability of remaining smoking abstinent.

Relating Nicotine Plasma Concentration to Momentary Craving Across Four Nicotine Replacement Therapy Formulations.

Tobacco use is a major health concern. To assist smoking cessation, nicotine replacement therapy (NRT) is used to reduce nicotine craving. We quantitatively described the relationship between nicotine pharmacokinetics (PKs) from NRTs and momentary craving, linking two different pharmacodynamic (PD) scales for measuring craving. The dataset comprised retrospective data from 17 clinical studies and included 1,077 adult smokers with 39,802 craving observations from four formulations: lozenge, gum, mouth spray, and patch. A PK/PD model was developed that linked individual predicted nicotine concentrations with the categorical and visual analogue PD scales through a joint bounded integer model. A maximum effect model, accounting for acute tolerance development, successfully related nicotine concentrations to momentary craving. Results showed that all formulations were similarly effective in reducing craving, albeit with a fourfold lower potency for the patch. Women were found to have a higher maximal effect of nicotine to reduce craving, compared with men.

Smoking cessation--but not smoking reduction--improves the annual decline in FEV1 in occupationally exposed workers.

INTRODUCTION: Individuals exposed both to cigarette smoke and respiratory pollutants at work incur a greater risk of development of airway hyperresponsiveness (AHR) and accelerated decline in forced expiratory volume in 1 s (FEV1) than that incurred by subjects undergoing each exposure separately. We examined whether smoking cessation or smoking reduction improves AHR and thereby slows down the decline in FEV1 in occupationally exposed workers. METHODS: We examined 165 workers (137 males and 28 females) participating in a smoking cessation programme. Nicotine tablets were used for smoking cessation or smoking reduction. Respiratory symptoms were assessed by questionnaire, FEV1 by spirometry and AHR by methacholine challenge test. At 1 year, subjects were classified into quitters, reducers, or continuing smokers. RESULTS: Sixty-seven subjects completed the study (32 quitters; 17 reducers; 18 continuing smokers). Respiratory symptoms improved markedly in quitters (P<0.001 for all comparisons) and less so in reducers (P values between 0.163 and 0.027). At 1 year, FEV1 had slightly but significantly improved in quitters (P=0.006 vs. smokers; P=0.038 vs. reducers) and markedly deteriorated in reducers and continuing smokers. Concurrent, 1-year change in AHR did not differ significantly among the groups. CONCLUSION: In occupationally exposed workers, stopping smoking markedly improved respiratory symptoms and, in males, slowed the annual decline in FEV1. Smoking reduction resulted in smaller improvements in symptoms but deterioration in FEV1. These findings were independent of AHR. While smoking cessation should remain the ultimate goal in workplace cessation programmes more studies are necessary to better ascertain the benefits of smoking reduction.

Smoking reduction treatment with 4-mg nicotine gum: a double-blind, randomized, placebo-controlled study.

BACKGROUND: Smoking reduction may provide a harm-reduction alternative treatment for smokers who are not ready to quit smoking. This study evaluated the efficacy of nicotine gum in helping smokers reduce or quit smoking. METHODS: This randomized, double-blind, placebo-controlled trial involved 364 smokers who were not ready to quit but were willing to reduce their smoking intensity. Participants received either 4-mg nicotine gum (n = 184) or placebo gum (n = 180) as desired for up to 12 months. The primary outcome was sustained smoking reduction, which was defined as a decrease in daily cigarette consumption of at least 50% compared with baseline. Secondary measures included point-prevalence abstinence, intention to quit, and cardiovascular risk markers. RESULTS: At 4 months, the sustained smoking reduction rate in the nicotine gum group was twice that of the placebo group (15.8% versus 6.7%, P = .008). Point-prevalence abstinence was 6.6% for the nicotine gum group and 2.2% for the placebo group (P = .07). At 13 months, there was a significant difference in the smoking reduction rate for the nicotine (8.2%) and placebo (2.8%) groups (P = .036). At month 13, the abstinence rates were 12% and 4.5% for the nicotine and placebo groups, respectively (P = .012). Concomitant use of nicotine gum and cigarette smoking was well tolerated. Carbon monoxide levels decreased significantly (P = .01). CONCLUSION: Nicotine gum may be an efficacious harm-reduction alternative for smokers who are not ready to quit and may promote smoking cessation, the ultimate goal in the treatment of tobacco dependence.

Developmental history of the Glover-Nilsson smoking behavioral questionnaire.

OBJECTIVE: To develop a simple, easily administered pencil-and-paper questionnaire to determine the degree to which behavioral patterns play a role in smoking dependence. METHODS: A modified Delphi technique was used to identify initial questions and to eliminate obvious duplications. Phase 2 utilized multiple statistical methods (principal components analysis, cluster analysis, stepwise multiple linear regression, cross tables, Mantel-Haenzel c2-test, and a Gamma test) to evaluate and reduce the number of questions from 18. RESULTS: These analyses yielded an 11-item questionnaire that can potentially assess behavioral dependence. CONCLUSION: It is hoped that the GN-SBQ will assist physicians, health care providers, and tobacco interventionists in identifying aspects of smoking addiction that are behavioral in nature. The need for future research is discussed.

Smoking reduction promotes smoking cessation: results from a double blind, randomized, placebo-controlled trial of nicotine gum with 2-year follow-up.

AIM: To test the effect of nicotine gum and placebo in smokers not motivated or not able to quit smoking with regard to smoking reduction and smoking cessation. DESIGN: This randomized study evaluated nicotine gum versus placebo for up to 1 year in 411 healthy smokers highly motivated to reduce cigarette use. Smoking reduction was defined as self-reported daily smoking less than 50% of baseline and any decrease (1 p.p.m. or more) in carbon monoxide. SETTING: Pulmonary department, Copenhagen, Denmark. FINDINGS: The overall success rate for sustained smoking reduction was significantly higher at all time-points for active versus placebo gum (6.3% versus 0.5% after 24 months). Nicotine gum achieved significantly higher point prevalence cessation rates than placebo at 12 and 24 months [11.2% versus 3.9% (odds ratio = 3.1; 95% CI, 1.4-7.2 and 9.3% versus 3.4% (odds ratio = 2.9; 95% CI, 1.2-7.1), respectively]. There was a linear relationship between decrease in number of daily cigarettes and decrease in plasma cotinine, exhaled carbon monoxide and plasma thiocyanate, with significantly greater reduction in the nicotine gum group after 4 and 12 months (maximum treatment duration) but not after 24 months. The decrease in toxin intake was smaller than the decline in daily cigarette consumption, suggesting that compensatory smoking occurred. CONCLUSIONS: Nicotine gum promoted cessation in this population of smokers unwilling to quit. Among reducers, the toxin intake correlated with reduced cigarette consumption although some compensatory smoking occurred.

Efficacy of the nicotine inhaler in smoking reduction: A double-blind, randomized trial.

Many smokers are not ready to quit but are interested in changing their smoking behavior, particularly if such a change is associated with a reduction in health risk. The present study evaluated the efficacy of the nicotine inhaler in reducing smoking. Exploratory studies assessed whether reduction in smoking was associated with reduction in markers of disease risk. A total of 429 healthy smokers (smoking at least 20 cigarettes/day) were randomly assigned to either nicotine-containing or placebo inhalers, which subjects were allowed to use ad libitum for up to 1 year. The nicotine inhaler was significantly superior to placebo in achieving reduction in daily cigarette consumption by at least 50% after 4 months, compared with baseline (18% vs. 8%, p = .004). Active treatment promoted smoking cessation: 8% of subjects in the nicotine group and 1% in the placebo group were abstinent at month 15. Throughout the study, smoking reduction, per se, independent of treatment group, was associated with a statistically significant decrease in exhaled carbon monoxide and serum cotinine and thiocyanate. Smoking reduction also improved established risk markers for cardiovascular disease over 4 months. The incidence of adverse events did not differ significantly between the active and placebo groups. The most common treatment-related adverse events were throat irritation and cough. In conclusion, the nicotine inhaler can help smokers who are unable or unwilling to quit to reduce daily cigarette consumption, which may be a health benefit on its own and may further promote quitting.

Effects of smoking cessation and reduction in asthmatics.

The present study examined the effect of smoking reduction and cessation on asthma regulation and biomarkers of exposure to cigarette smoke. In a prospective open design, we allocated 220 asthmatics among three groups: (a) Smoking reduction (reducers), with the aim of smoking fewer than seven cigarettes per day, (b) complete smoking cessation (abstainers), or (c) continuation of usual smoking (continuing smokers). Subjects used nicotine chewing gum or an oral nicotine inhaler to promote reduction and cessation. We monitored changes in the biomarkers carbon monoxide, cotinine, and thiocyanate, and in peak flow, medicine use, bronchial reactivity, and asthma symptoms. The analysis used the three outcome groups, regardless of original allocation to treatment groups. At 4 months, analysis of abstainers (n = 27), reducers (n = 33), and continuing smokers (n = 50) showed marked, statistically significant decreases in expired carbon monoxide of 17 ppm (abstainers) and 15 ppm (reducers); in plasma cotinine of 124 ng/ml (abstainers) and 122 ng/ml (reducers); and in plasma thiocyanate of 5.03 ng/ml (abstainers) and 3.74 ng/m (reducers). For abstainers, we observed improvements in the asthma-specific quality-of-life score, and reductions in self-reported day and night use of rescue beta2-agonists, in doses of inhaled corticosteroids, in daytime asthma symptoms, and in bronchial hyperreactivity. For reducers, smaller improvements occurred for night use of rescue beta2-agonists, doses of inhaled corticosteroids, and bronchial hyperreactivity. Smoking cessation resulted in a marked decrease in three biomarkers of cigarette smoke inhalation and improved asthma regulation, whereas smoking reduction had a less pronounced effect on biomarkers and only a small effect on asthma regulation.

Influence of long-term smoking reduction on health risk markers and quality of life.

We have recently published efficacy and safety data of a study using an oral nicotine inhaler in smoking reduction. The current analysis was undertaken to assess the secondary objectives of the trial: the influence of long-term smoking reduction on health risk markers. Four hundred healthy volunteers, unable or unwilling to stop smoking immediately, were enrolled in a double-blind, randomized, placebo-controlled trial in smoking reduction; 310 were evaluable up to 2 years. Participants were randomized to active or placebo inhalers as needed for up to 18 months, with subjects encouraged to reduce their smoking as much as possible; counseling took place over a 2-year period. For the current prospective cohort study, the number of daily cigarettes, carbon monoxide (CO), cotinine, cardiovascular risk factors, pulmonary function tests, and quality of life were compared between successful reducers (n = 25) and unsuccessful reducers (control group, n = 285). Success was defined as a reduction of daily cigarettes of at least 50% from week 6 to 2 years, verified by a decrease in exhaled CO at all visits compared with baseline. At 2 years, successful reducers showed a significantly greater decrease in cotinine levels (60% vs. 1%, p < 0.001), cholesterol/high-density lipoprotein (HDL) ratios (-2.42 vs. -1.67, p = 0.025), hemoglobin concentrations (-5.67 vs. -1.34 g/l, p = 0.023), pulse rate (-3.7 vs. +1.0 bpm, p = 0.043), and significantly improved general health score (9.40 vs. 2.34, p = 0.049); whereas no difference was found in forced expiratory volume during 1 s (FEV1) and forced vital capacity (FVC) compared with controls. The benefits of long-term smoking reduction of at least 50% of daily cigarettes were not offset by compensatory smoking, and the marked decrease in markers of smoke exposure had a positive influence on several cardiovascular risk markers and quality of life assessments.