Clinical and pharmacokinetic properties of a transdermal nicotine patch

Transdermal Nicotine Patch Increases the Number and Function of Endothelial Progenitor Cells in Young Healthy Nonsmokers without Adverse Hemodynamic Effects

Transdermal nicotine patches (TNPs), administering nicotine into the bloodstream through skin, have been widely used as nicotine replacement therapy, and exposure to nicotine can be detected by measurement of plasma cotinine concentration. In animal studies, nicotine treatment could increase the number of endothelial progenitor cells (EPCs), but the effect of TNPs on circulating EPCs and their activity in humans remained unclear. This study aimed to explore the influence of TNPs on circulating EPCs with surface markers of CD34, CD133, and/or KDR, and colony-forming function plus migration activity of early EPCs derived from cultured peripheral blood mononuclear cells before and after TNP treatments in young healthy nonsmokers. In parallel, pulse wave analysis (PWA) was applied to evaluate the vascular effect of TNP treatments. Twenty-one participants (25.8 ± 3.6 years old, 10 males) used TNP (nicotine: 4.2 mg/day) for 7 consecutive days. During the treatment, the CD34+ EPCs progressively increased in number. In addition, the number of EPCs positive for CD34/KDR, CD133, and CD34/CD133 were also increased on day 7 of the treatment. Furthermore, the early EPC colony-forming function and migration activity were increased with the plasma cotinine level positively correlating with change in colony-forming unit number. PWA analyses on day 7, compared with pretreatment, did not show significant change except diastolic pressure time index, which was prolonged and implied potential vascular benefit. In conclusion, 7-day TNP treatments could be a practical strategy to enhance angiogenesis of circulating EPCs to alleviate tissue ischemia without any hemodynamic concern.

Oral side effects of locally delivered nicotine replacement therapy: A meta-analysis of randomized controlled trials

BACKGROUND

Nicotine replacement therapy is the first choice pharmacotherapy for smoking cessation. Oral side effects caused due to NRT lead to discontinuation of treatment. The objective of this meta-analysis was to look for the certainty of evidence on the number of patients that reported oral side effects due to the use of NRT.

METHOD

Eligible studies were selected and data extraction was carried out independently into a pre-tested data extraction form. Risk of bias was assessed using Cochrane Tool. The heterogeneity between the studies was assessed using Chi-square and I2 tests. Mean difference and Odds ratio at 95% confidence interval were the effect estimates. GRADE working group approach was used to assess the quality of evidence.

RESULTS

Twenty-eight studies were included with moderate to low risk of bias. The pooled estimates revealed a statistically significant number of patients developed mouth or throat irritation (2.54 [1.23, 5.25]), or oral soreness (2.22 [1.40, 3.55]) or gastric reflux or vomiting (1.97 [1.34, 2.90]) due to NRT.

CONCLUSION

It is important to understand that significant implications are caused due to NRT, on oral health. All patients on NRT must adhere to their regular dentist visits and must check their oral mucosa before initiating NRT.

Smoking cessation medicines and e-cigarettes: a systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

Cigarette smoking is one of the leading causes of early death. Varenicline [Champix (UK), Pfizer Europe MA EEIG, Brussels, Belgium; or Chantix (USA), Pfizer Inc., Mission, KS, USA], bupropion (Zyban; GlaxoSmithKline, Brentford, UK) and nicotine replacement therapy are licensed aids for quitting smoking in the UK. Although not licensed, e-cigarettes may also be used in English smoking cessation services. Concerns have been raised about the safety of these medicines and e-cigarettes.

OBJECTIVES

To determine the clinical effectiveness, safety and cost-effectiveness of smoking cessation medicines and e-cigarettes.

DESIGN

Systematic reviews, network meta-analyses and cost-effectiveness analysis informed by the network meta-analysis results.

SETTING

Primary care practices, hospitals, clinics, universities, workplaces, nursing or residential homes.

PARTICIPANTS

Smokers aged ≥ 18 years of all ethnicities using UK-licensed smoking cessation therapies and/or e-cigarettes.

INTERVENTIONS

Varenicline, bupropion and nicotine replacement therapy as monotherapies and in combination treatments at standard, low or high dose, combination nicotine replacement therapy and e-cigarette monotherapies.

MAIN OUTCOME MEASURES

Effectiveness - continuous or sustained abstinence. Safety - serious adverse events, major adverse cardiovascular events and major adverse neuropsychiatric events.

DATA SOURCES

Ten databases, reference lists of relevant research articles and previous reviews. Searches were performed from inception until 16 March 2017 and updated on 19 February 2019.

REVIEW METHODS

Three reviewers screened the search results. Data were extracted and risk of bias was assessed by one reviewer and checked by the other reviewers. Network meta-analyses were conducted for effectiveness and safety outcomes. Cost-effectiveness was evaluated using an amended version of the Benefits of Smoking Cessation on Outcomes model.

RESULTS

Most monotherapies and combination treatments were more effective than placebo at achieving sustained abstinence. Varenicline standard plus nicotine replacement therapy standard (odds ratio 5.75, 95% credible interval 2.27 to 14.90) was ranked first for sustained abstinence, followed by e-cigarette low (odds ratio 3.22, 95% credible interval 0.97 to 12.60), although these estimates have high uncertainty. We found effect modification for counselling and dependence, with a higher proportion of smokers who received counselling achieving sustained abstinence than those who did not receive counselling, and higher odds of sustained abstinence among participants with higher average dependence scores. We found that bupropion standard increased odds of serious adverse events compared with placebo (odds ratio 1.27, 95% credible interval 1.04 to 1.58). There were no differences between interventions in terms of major adverse cardiovascular events. There was evidence of increased odds of major adverse neuropsychiatric events for smokers randomised to varenicline standard compared with those randomised to bupropion standard (odds ratio 1.43, 95% credible interval 1.02 to 2.09). There was a high level of uncertainty about the most cost-effective intervention, although all were cost-effective compared with nicotine replacement therapy low at the £20,000 per quality-adjusted life-year threshold. E-cigarette low appeared to be most cost-effective in the base case, followed by varenicline standard plus nicotine replacement therapy standard. When the impact of major adverse neuropsychiatric events was excluded, varenicline standard plus nicotine replacement therapy standard was most cost-effective, followed by varenicline low plus nicotine replacement therapy standard. When limited to licensed interventions in the UK, nicotine replacement therapy standard was most cost-effective, followed by varenicline standard.

LIMITATIONS

Comparisons between active interventions were informed almost exclusively by indirect evidence. Findings were imprecise because of the small numbers of adverse events identified.

CONCLUSIONS

Combined therapies of medicines are among the most clinically effective, safe and cost-effective treatment options for smokers. Although the combined therapy of nicotine replacement therapy and varenicline at standard doses was the most effective treatment, this is currently unlicensed for use in the UK.

FUTURE WORK

Researchers should examine the use of these treatments alongside counselling and continue investigating the long-term effectiveness and safety of e-cigarettes for smoking cessation compared with active interventions such as nicotine replacement therapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041302.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 59. See the NIHR Journals Library website for further project information.

Cold-induced vasodilation in abstinent smokers with and without a 12-hour nicotine patch

This study was designed to identify the effects of a 12-h nicotine patch administration on cold induced vasodilation (CIVD) in healthy young chronic smokers following 16 h of abstinence from smoking. Two laser Doppler probes and temperature thermocouples were placed on the dorsal part of the distal phalanx of the middle and ring fingers of 7 smokers (>12 cigarettes/day). Following 16 h of abstinence from smoking, smokers were tested with and without administration of a 21 mg transdermal nicotine patch (NicoDerm^® ). Each participant's right hand was immersed in cold (~5°C) water for 40 min. Cutaneous vascular conductance (CVC) was calculated from non-invasive arterial finger blood pressure and skin blood flow and expressed as a percentage of peak CVC observed during hand skin heating to 44°C. For comparison purposes, the CIVD response of a non-smoking cohort without nicotine patch (n = 10) was also examined. Baseline CVC was similar in smokers and non-smokers (27.8 ± 12.6 CVC % peak). The initial vasoconstriction during cold-water immersion decreased skin blood flow to 4.0 ± 3.9 CVC % peak in both smokers and non-smokers. The onset of CIVD in smokers (4.5 ± 1.5 min) was delayed compared to non-smoker (3.3 ± 0.8 min, p < .05). The area under the CVC %peak-time curve during cold-water immersion averaged 1250 ± 388 CVC %peak · min in non-smokers which was larger (p < .05) than smokers with or without nicotine (789 ± 542 and 862 ± 517 CVC %peak · min, respectively). Chronic smoking impaired the CIVD response to cold-water immersion of the hand; however, the impaired CIVD response in 16 h of abstinence from smoking was not influenced by application of a 21 mg transdermal nicotine patch.

Nicotine replacement therapy versus control for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

OBJECTIVES

To determine the effectiveness and safety of nicotine replacement therapy (NRT), including gum, transdermal patch, intranasal spray and inhaled and oral preparations, for achieving long-term smoking cessation, compared to placebo or 'no NRT' interventions.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search is July 2017.

SELECTION CRITERIA

Randomized trials in people motivated to quit which compared NRT to placebo or to no treatment. We excluded trials that did not report cessation rates, and those with follow-up of less than six months, except for those in pregnancy (where less than six months, these were excluded from the main analysis). We recorded adverse events from included and excluded studies that compared NRT with placebo. Studies comparing different types, durations, and doses of NRT, and studies comparing NRT to other pharmacotherapies, are covered in separate reviews.

DATA COLLECTION AND ANALYSIS

Screening, data extraction and 'Risk of bias' assessment followed standard Cochrane methods. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 136 studies; 133 with 64,640 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The majority of studies were conducted in adults and had similar numbers of men and women. People enrolled in the studies typically smoked at least 15 cigarettes a day at the start of the studies. We judged the evidence to be of high quality; we judged most studies to be at high or unclear risk of bias but restricting the analysis to only those studies at low risk of bias did not significantly alter the result. The RR of abstinence for any form of NRT relative to control was 1.55 (95% confidence interval (CI) 1.49 to 1.61). The pooled RRs for each type were 1.49 (95% CI 1.40 to 1.60, 56 trials, 22,581 participants) for nicotine gum; 1.64 (95% CI 1.53 to 1.75, 51 trials, 25,754 participants) for nicotine patch; 1.52 (95% CI 1.32 to 1.74, 8 trials, 4439 participants) for oral tablets/lozenges; 1.90 (95% CI 1.36 to 2.67, 4 trials, 976 participants) for nicotine inhalator; and 2.02 (95% CI 1.49 to 2.73, 4 trials, 887 participants) for nicotine nasal spray. The effects were largely independent of the definition of abstinence, the intensity of additional support provided or the setting in which the NRT was offered. A subset of six trials conducted in pregnant women found a statistically significant benefit of NRT on abstinence close to the time of delivery (RR 1.32, 95% CI 1.04 to 1.69; 2129 participants); in the four trials that followed up participants post-partum the result was no longer statistically significant (RR 1.29, 95% CI 0.90 to 1.86; 1675 participants). Adverse events from using NRT were related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. Attempts to quantitatively synthesize the incidence of various adverse effects were hindered by extensive variation in reporting the nature, timing and duration of symptoms. The odds ratio (OR) of chest pains or palpitations for any form of NRT relative to control was 1.88 (95% CI 1.37 to 2.57, 15 included and excluded trials, 11,074 participants). However, chest pains and palpitations were rare in both groups and serious adverse events were extremely rare.

AUTHORS' CONCLUSIONS

There is high-quality evidence that all of the licensed forms of NRT (gum, transdermal patch, nasal spray, inhalator and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50% to 60%, regardless of setting, and further research is very unlikely to change our confidence in the estimate of the effect. The relative effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT. NRT often causes minor irritation of the site through which it is administered, and in rare cases can cause non-ischaemic chest pain and palpitations.

An efficient early phase 2 procedure to screen medications for efficacy in smoking cessation

RATIONALE

Initial screening of new medications for potential efficacy (i.e., Food and Drug Administration (FDA) early phase 2), such as in aiding smoking cessation, should be efficient in identifying which drugs do, or do not, warrant more extensive (and expensive) clinical testing.

OBJECTIVES

This focused review outlines our research on development, evaluation, and validation of an efficient crossover procedure for sensitivity in detecting medication efficacy for smoking cessation. First-line FDA-approved medications of nicotine patch, varenicline, and bupropion were tested as model drugs, in three separate placebo-controlled studies. We also tested specificity of our procedure in identifying a drug that lacks efficacy, using modafinil.

RESULTS

This crossover procedure showed sensitivity (increased days of abstinence) during week-long "practice" quit attempts with each of the active cessation medications (positive controls) versus placebo, but not with modafinil (negative control) versus placebo, as hypothesized. Sensitivity to medication efficacy signal was observed only in smokers high in intrinsic quit motivation (i.e., already preparing to quit soon) and not smokers low in intrinsic quit motivation, even if monetarily reinforced for abstinence (i.e., given extrinsic motivation).

CONCLUSIONS

A crossover procedure requiring less time and fewer subjects than formal trials may provide an efficient strategy for a go/no-go decision whether to advance to subsequent phase 2 randomized clinical trials with a novel drug. Future research is needed to replicate our results and evaluate this procedure with novel compounds, identify factors that may limit its utility, and evaluate its applicability to testing efficacy of compounds for treating other forms of addiction.

Nicotine replacement therapy for smoking cessation

BACKGROUND

The aim of nicotine replacement therapy (NRT) is to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

OBJECTIVES

The aims of this review were: To determine the effect of NRT compared to placebo in aiding smoking cessation, and to consider whether there is a difference in effect for the different forms of NRT (chewing gum, transdermal patches, oral and nasal sprays, inhalers and tablets/lozenges) in achieving abstinence from cigarettes. To determine whether the effect is influenced by the dosage, form and timing of use of NRT; the intensity of additional advice and support offered to the smoker; or the clinical setting in which the smoker is recruited and treated. To determine whether combinations of NRT are more likely to lead to successful quitting than one type alone. To determine whether NRT is more or less likely to lead to successful quitting compared to other pharmacotherapies.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search July 2012.

SELECTION CRITERIA

Randomized trials in which NRT was compared to placebo or to no treatment, or where different doses of NRT were compared. We excluded trials which did not report cessation rates, and those with follow-up of less than six months.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of participants, the dose, duration and form of nicotine therapy, the outcome measures, method of randomization, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 150 trials; 117 with over 50,000 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The risk ratio (RR) of abstinence for any form of NRT relative to control was 1.60 (95% confidence interval [CI] 1.53 to 1.68). The pooled RRs for each type were 1.49 (95% CI 1.40 to 1.60, 55 trials) for nicotine gum; 1.64 (95% CI 1.52 to 1.78, 43 trials) for nicotine patch; 1.95 (95% CI 1.61 to 2.36, 6 trials) for oral tablets/lozenges; 1.90 (95% CI 1.36 to 2.67, 4 trials) for nicotine inhaler; and 2.02 (95% CI 1.49 to 2.73, 4 trials) for nicotine nasal spray. One trial of oral spray had an RR of 2.48 (95% CI 1.24 to 4.94). The effects were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. The effect was similar in a small group of studies that aimed to assess use of NRT obtained without a prescription. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2 mg gum, but weaker evidence of a benefit from higher doses of patch. There was evidence that combining a nicotine patch with a rapid delivery form of NRT was more effective than a single type of NRT (RR 1.34, 95% CI 1.18 to 1.51, 9 trials). The RR for NRT used for a short period prior to the quit date was 1.18 (95% CI 0.98 to 1.40, 8 trials), just missing statistical significance, though the efficacy increased when we pooled only patch trials and when we removed one trial in which confounding was likely. Five studies directly compared NRT to a non-nicotine pharmacotherapy, bupropion; there was no evidence of a difference in efficacy (RR 1.01; 95% CI 0.87 to 1.18). A combination of NRT and bupropion was more effective than bupropion alone (RR 1.24; 95% CI 1.06 to 1.45, 4 trials). Adverse effects from using NRT are related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. There is no evidence that NRT increases the risk of heart attacks.

AUTHORS' CONCLUSIONS

All of the commercially available forms of NRT (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50 to 70%, regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT.

Nicotine replacement therapy for smoking cessation

BACKGROUND

The aim of nicotine replacement therapy (NRT) is temporarily to replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

OBJECTIVES

The aims of this review were:To determine the effect of NRT compared to placebo in aiding smoking cessation, and to consider whether there is a difference in effect for the different forms of NRT (chewing gum, transdermal patches, nasal spray, inhalers and tablets/lozenges) in achieving abstinence from cigarettes. To determine whether the effect is influenced by the dosage, form and timing of use of NRT; the intensity of additional advice and support offered to the smoker; or the clinical setting in which the smoker is recruited and treated. To determine whether combinations of NRT are more likely to lead to successful quitting than one type alone. To determine whether NRT is more or less likely to lead to successful quitting compared to other pharmacotherapies.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register for papers with 'nicotine' or 'NRT' in the title, abstract or keywords. Date of most recent search July 2007.

SELECTION CRITERIA

Randomized trials in which NRT was compared to placebo or to no treatment, or where different doses of NRT were compared. We excluded trials which did not report cessation rates, and those with follow up of less than six months.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of participants, the dose, duration and form of nicotine therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months of follow up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 132 trials; 111 with over 40,000 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The RR of abstinence for any form of NRT relative to control was 1.58 (95% confidence interval [CI]: 1.50 to 1.66). The pooled RR for each type were 1.43 (95% CI: 1.33 to 1.53, 53 trials) for nicotine gum; 1.66 (95% CI: 1.53 to 1.81, 41 trials) for nicotine patch; 1.90 (95% CI: 1.36 to 2.67, 4 trials) for nicotine inhaler; 2.00 (95% CI: 1.63 to 2.45, 6 trials) for oral tablets/lozenges; and 2.02 (95% CI: 1.49 to 3.73, 4 trials) for nicotine nasal spray. The effects were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. The effect was similar in a small group of studies that aimed to assess use of NRT obtained without a prescription. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2 mg gum, but weaker evidence of a benefit from higher doses of patch. There was evidence that combining a nicotine patch with a rapid delivery form of NRT was more effective than a single type of NRT. Only one study directly compared NRT to another pharmacotherapy. In this study quit rates with nicotine patch were lower than with the antidepressant bupropion.

AUTHORS' CONCLUSIONS

All of the commercially available forms of NRT (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50-70%, regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT.

Transdermal nicotine for smoking cessation in postmenopausal women

This study examined the efficacy of transdermal nicotine in postmenopausal smokers, and whether a history of depression or hormone replacement therapy (HRT) moderated smoking cessation outcomes. Postmenopausal smokers (N=152) received intensive smoking cessation counseling and were randomly assigned to use either a 21-mg nicotine patch for 3 months, with a 1-month taper, or a placebo patch. The primary outcome was biochemically validated 7-day point prevalence smoking abstinence during treatment (i.e., 1, 2, 6, and 12 weeks after the quit date) and 1 year after study medication was discontinued. Subjects who received transdermal nicotine were significantly more likely than placebo-treated subjects to remain abstinent from smoking during treatment, but not at the 1-year follow-up. The majority of subjects (>50%) in both groups accurately identified their treatment assignment. History of depression was associated with a decreased likelihood to abstain from smoking throughout the study. HRT did not moderate smoking outcomes. These data indicate that transdermal nicotine may provide short-term benefits for smoking cessation in postmenopausal women. However, efforts are needed to improve long-term abstinence rates and smoking outcomes among women with a history of depression.

The effects of nicotine on the metabolic and hormonal responses during acute cold exposure

OBJECTIVE

To examine the effects of nicotine on the metabolic and hormonal responses during acute cold exposure.

METHODS

Participants in this study included 6 men and 5 women between the ages of 19 and 25 years. Each subject performed 2 cold-air trials (CATs) consisting of a 30-minute baseline (BASE) period and a 120-minute exposure to 10 degree C air. One CAT was performed after a nicotine (NIC) dosing using a 21-mg transdermal patch, whereas the other CAT was performed after a placebo (PL) treatment. Blood samples for metabolic and hormonal measurements were obtained at the end of BASE and immediately after the cold exposure.

RESULTS

When examining the sexes separately, there was no difference in norepinephrine between PL and NIC (P = .066). There was also no difference in epinephrine between PL and NIC in either sex (P = .634). From BASE to 120 minutes of the CAT, there was a significant decrease in cortisol (P = .036), but this response was similar between the 2 treatments (P = .077). Glucose and glycerol concentrations were not different between the PL and NIC treatments. At BASE, nonesterified fatty acid (NEFA) concentration was lower during PL compared with NIC (P = .021); however, at 120 minutes of the CAT, NEFA was greater during PL compared with NIC (P = .035).

CONCLUSIONS

During 120 minutes of cold exposure, NIC resulted in alterations in the responses in NEFA, whereas the other blood measurements were not significantly different between the 2 groups.

Cutaneous Reactions to Transdermal Therapeutic Systems

Transdermal therapeutic systems have been increasingly used in the past two decades. However, cutaneous side effects are fairly common and may result in poor patient compliance. This review article summarizes the spectrum of reactions due to transdermal therapeutic systems and provides a current list of known allergens.

Smoking and sleep disorders

Cigarette smoking is the most important cause of preventable disease, disability, and premature death in the United States. In addition to adverse effects on respiratory, cardiovascular, cerebrovascular, and other systems, accumulating evidence indicates that cigarette smoking may also increase morbidity by adversely affecting sleep. This article focuses on the effects of cigarette smoking, nicotine, and pharmacologic agents used for smoking cessation on neuronal systems regulating sleep and clinically apparent sleep disorders.

Residential treatment for smokeless tobacco use: a case series

We developed and implemented a novel 8-day residential treatment program for smokeless tobacco (ST) use. A multidisciplinary team delivered behavioral treatment, nicotine patches were adjusted to achieve 100% replacement of baseline peak serum nicotine concentrations, and bupropion sustained-release was prescribed. Mean participant age (+/- SD) was 47.4 +/- 18.2 years. Mean nicotine patch dose at program end was 43.2 mg/day +/- 13.9 (range 14 to 66 mg/d). Median percent replacement by serum nicotine concentrations was 86.6% (IQR: 75-113.8%). At 1 year, the biochemically-confirmed (urine anabasine <2.0 ng/mL) self-reported 7-day point prevalence tobacco abstinence rate was 58% (14/24). A residential treatment program for ST users may be effective. More research is needed to replicate our findings and determine if comparable abstinence rates can be achieved with outpatient ST treatment programs using similar behavioral and pharmacotherapies.

Nicotine replacement therapy for smoking cessation

BACKGROUND

The aim of nicotine replacement therapy (NRT) is to replace nicotine from cigarettes. This reduces withdrawal symptoms associated with smoking cessation thus helping resist the urge to smoke cigarettes.

OBJECTIVES

The aims of this review were:to determine the effectiveness of the different forms of NRT (chewing gum, transdermal patches, nasal spray, inhalers and tablets) in achieving abstinence from cigarettes, or a sustained reduction in amount smoked; to determine whether the effect is influenced by the clinical setting in which the smoker is recruited and treated, the dosage and form of the NRT used, or the intensity of additional advice and support offered to the smoker; to determine whether combinations of NRT are more effective than one type alone; to determine its effectiveness compared to other pharmacotherapies.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register in March 2004.

SELECTION CRITERIA

Randomized trials in which NRT was compared to placebo or to no treatment, or where different doses of NRT were compared. We excluded trials which did not report cessation rates, and those with follow up of less than six months.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of participants, the dose, duration and form of nicotine therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months of follow up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. For each study we calculated summary odds ratios. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed effect model.

MAIN RESULTS

We identified 123 trials; 103 contributing to the primary comparison between NRT and a placebo or non-NRT control group. The odds ratio (OR) for abstinence with NRT compared to control was 1.77 (95% confidence intervals (CI): 1.66 to 1.88). The ORs for the different forms of NRT were 1.66 (95% CI: 1.52 to 1.81) for gum, 1.81 (95% CI: 1.63 to 2.02) for patches, 2.35 (95% CI: 1.63 to 3.38) for nasal spray, 2.14 (95% CI: 1.44 to 3.18) for inhaled nicotine and 2.05 (95% CI: 1.62 to 2.59) for nicotine sublingual tablet/lozenge. These odds were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2 mg gum (OR 2.20, 95% CI: 1.85 to 3.25). There was weak evidence that combinations of forms of NRT are more effective. Higher doses of nicotine patch may produce small increases in quit rates. Only one study directly compared NRT to another pharmacotherapy. In this study quit rates with bupropion were higher than with nicotine patch or placebo.

REVIEWERS' CONCLUSIONS

All of the commercially available forms of NRT (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) are effective as part of a strategy to promote smoking cessation. They increase the odds of quitting approximately 1.5 to 2 fold regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the smoker. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT.

The effects of transdermal nicotine on inspection time

RATIONALE

The acute administration of nicotine via a cigarette has been demonstrated to enhance inspection time (IT), a measure of rapid visual information processing, while the nicotinic antagonist mecamylamine impairs IT. However, as transdermal nicotine patches provide a slow delivery of nicotine, it is unclear if they produce similar effects to nicotine administered by more rapid methods.

OBJECTIVES

To examine the effects of transdermal nicotine on inspection time.

METHODS

Ten moderate smokers were administered nicotine (21 mg/day) or placebo via a transdermal patch in a randomized, double-blind, repeated measures design. Subjects were administered the IT task at baseline, then 1, 3, and 6 h subsequent to patch application.

RESULTS

The change in IT from baseline was significantly different in the nicotine condition, relative to placebo, at 3 h but not 1 or 6 h.

CONCLUSIONS

The findings suggest that nicotine administered via transdermal patches improves IT, but this improvement may be subject to tolerance. Data from previous studies on tolerance to the cognitive effects of nicotine have been inconclusive. However, the slow delivery of nicotine from patches may be more likely to produce such effects.

Satiety threshold: a quantitative model of maintained cocaine self-administration

The intervals between self-injections of cocaine by rats are defined by an equation that contains only three parameters: the dose of cocaine administered, the elimination half-life of cocaine, and an amount of cocaine in the body, which we have termed the cocaine satiety threshold. This latter parameter is defined as the maximal level of cocaine at which the probability of self-administration approximates one and above which the probability of self-administration is low. The mathematical model generated mean values for the satiety threshold and the functional elimination half-life of cocaine of approximately 1.7 mg/kg (i.v.) and 8.2 min, respectively. Therefore, the simple equations presented here permit the measurement of the pharmacokinetics and pharmacodynamics of cocaine using self-administration behavior as a bioassay. Our satiety model predicts that when cocaine levels are maintained above the satiety threshold, rats would not self-administer cocaine. The elimination rate of cocaine at the satiety threshold was calculated to be approximately 2 microg kg(-1) s(-1). Therefore, an infusion of cocaine at this rate should maintain cocaine levels fractionally above the satiety threshold. A continuous infusion of cocaine at this rate prevented cocaine self-administration for the duration of the infusion, thereby confirming the validity of the satiety model. These equations provide a quantitative description of cocaine self-administration and contain no subjective terms, implying that concepts such as "craving", drug "wanting" and "liking" and "reinforcement", used in psychologically oriented models, are not necessary for descriptions of this behavior in rats.

Nicotine therapy for ulcerative colitis: a review of rationale, mechanisms, pharmacology, and clinical results

Smoking is protective against developing ulcerative colitis. Nicotine may be the cause of this protective effect. Controlled trials have demonstrated efficacy of transdermal nicotine for active ulcerative colitis. Side effects observed with transdermal nicotine include contact dermatitis, nausea, and lightheadedness. Topical administration of nicotine to the colon reduces nicotine blood concentrations and side effects, and may be of clinical benefit.

Application of serum nicotine and plasma cotinine concentrations to assessment of nicotine replacement in light, moderate, and heavy smokers undergoing transdermal therapy

As part of a clinical trial investigating the level of nicotine replacement with different doses of transdermal therapy for smoking cessation, peak and trough serum nicotine and plasma cotinine concentrations were measured in 70 subjects while they were actively smoking (baseline) and daily for 6 consecutive inpatient days while they were receiving transdermal nicotine. Subjects were randomly assigned to a daily 24-hour patch delivering a transdermal nicotine dose of 0, 11, 22, or 44 mg and stratified by self-reported smoking rate as either light (10-15 cigarettes per day), moderate (16-30 cigarettes per day), or heavy (>30 cigarettes per day). Steady-state concentrations of nicotine and cotinine were attained in 1 and 3 days, respectively, at all doses and were independent of baseline smoking rate. Mean percentage replacement of nicotine was calculated by dividing steady-state peak nicotine or cotinine concentrations by their respective baseline concentrations. Significant underreplacement occurred in subjects receiving the 11 mg/day patch regardless of baseline smoking rate. Underreplacement also occurred in moderate and heavy smokers receiving 22 mg/day and in light smokers at this same dose. Complete replacement occurred only in subjects receiving the 44 mg/day patch. These results have several implications for transdermal nicotine therapy. First, with the higher nicotine and cotinine levels observed with heavier smoking, it is inherent that one size does not fit all, and there is a need to consider more individualization of dosage for nicotine patch therapy. Second, there is substantial underreplacement with the 22 mg/day dose in moderate to heavy smokers and in some light smokers. Third, even with twice the usual dose (i.e., 44 mg/day), there was no accumulation of either nicotine or cotinine. Plasma cotinine levels after achievement of steady state (i.e., after 3 days of patch therapy) can be collected at any time and used to calculate percent replacement using baseline levels.

Application of urine nicotine and cotinine excretion rates to assessment of nicotine replacement in light, moderate, and heavy smokers undergoing transdermal therapy

As part of a clinical trial investigating the level of nicotine replacement with different doses of transdermal therapy for smoking cessation, urine excretion rates of nicotine and cotinine were measured in 70 subjects while they were actively smoking (baseline) and for 6 consecutive inpatient days while they were receiving transdermal nicotine therapy. Subjects were stratified according to baseline smoking rate as light (10-15 cigarettes per day), moderate (16-30 cigarettes per day), or heavy (>30 cigarettes per day) smokers and randomly assigned to a daily 24-hour patch delivering a transdermal nicotine dose of 0, 11, 22, or 44 mg. Steady-state excretion rates of nicotine and cotinine were attained in 2 and 3 days, respectively, at all doses and were independent of smoking rate. Percentage replacement of nicotine was calculated by dividing steady-state nicotine or cotinine excretion rates by their respective baseline excretion rates. Significant underreplacement occurred with the 11-mg/day dose, particularly in moderate and heavy smokers (<50%). At a dose of 22 mg/day, nicotine replacement was still <100% in the majority of subjects. Only at a dose of 44 mg/day did mean replacement exceed 100% regardless of baseline smoking rate.

Autonomic effects of nicotine patch administration in habitual cigarette smokers: a double-blind, placebo-controlled study using spectral analysis of RR interval and systolic arterial pressure variabilities

Nicotine patch administration is often used to sustain tobacco abstinence in smoking-cessation programs. There is some concern regarding safety issues, as a consequence of the sympathomimetic action of nicotine. We used spectral analysis of RR interval and (noninvasive) systolic arterial pressure (SAP) beat-by-beat variabilities in a crossover double-blind design to assess the autonomic effects of cigarette smoking, of transdermal nicotine, and of placebo. The study group consisted of 27 heavy smokers (age 43 +/- 2 years). The RR interval and its variability were significantly reduced in the smoking group, as compared with nicotine or placebo groups. The LF component of RR interval variability (in normalized units, nu), and the LF/HF ratio showed greatest values during smoking, as compared with placebo. Values of LF(RR) and LF/HF during nicotine patch treatment were slightly, but not significantly, greater than observed with placebo. No differences were observed in SAP and its variability components. The index alpha (a frequency domain measure of baroreflex gain) was minimal in the smoking period. Habitual cigarette smoking is associated with signs of sympathetic predominance in the autonomic control of the sinoatrial (SA) node. Nicotine patches produce only minor disturbances of autonomic regulation. This corroborates their safe use in smoking-cessation strategies.

A meta-analysis to assess the incidence of adverse effects associated with the transdermal nicotine patch

To estimate the frequency of adverse effects associated with the use of the transdermal nicotine patch, we abstracted and analysed data from 47 reports of 35 clinical trials. The meta-analysis presented here represents a synthesis of data from 41 groups of nicotine patch recipients totalling 5501 patients, and 33 groups of placebo recipients totalling 3752 patients. Smoking abstinence was the primary outcome in 32 of the trials, and relief of colitis symptoms was the primary outcome in 2 of the trials; 1 study of contact sensitisation was included in the skin irritation analysis. The patch was clearly effective as an aid to smoking abstinence. Despite the large number of patients in the analysis, few adverse cardiovascular outcomes (myocardial infarction, stroke, tachycardia, arrhythmia, angina) were reported, and no excess of these outcomes was detected among patients assigned to nicotine-patch use. The incidences of several minor adverse effects were clearly elevated among the nicotine-patch groups, especially sleep disturbances, nausea or vomiting, localised skin irritation and respiratory symptoms, but the background rates and risk ratios varied considerably across studies. The incidence of nausea or vomiting appeared to be lowest when the patch dose was tapered. The results of this meta-analysis indicate that very large studies would be needed to assess the effect of the patch, if any, on serious, rare outcomes. These results also suggest that the rate of minor adverse effects might be lowered by modifying patch-use protocols.

Usage patterns of transdermal nicotine when purchased as a non-prescription medicine from pharmacies

OBJECTIVE

To assess nicotine patch use in smokers who purchased the product as a non-prescription medicine from pharmacies.

DESIGN

A questionnaire administered at the time of purchase.

SETTING

Community pharmacies throughout New Zealand.

SUBJECTS

A total of 805 male and female purchasers of nicotine patches aged 18 through 87 years.

MAIN OUTCOME MEASURES

Patterns of usage including self-reported smoking history, previous quit-smoking attempts, previous and current use of transdermal nicotine and other products, side effects, and concomitant smoking.

RESULTS

Most respondents (74%) had attempted to quit smoking previously, many of whom (53%) had used a non-prescription nicotine replacement product. Approximately 60% of purchasers were first-time users. For those continuing a course of treatment, there was no evidence of use for longer than the manufacturer's recommendation (12 weeks). Twenty-eight per cent of respondents reported continuing smoking while using transdermal nicotine, although the number of cigarettes smoked was much less than in the reported smoking history. Side effects were reported by 24% of patch users in the current course, but there was no evidence of significant safety problems.

CONCLUSIONS

This survey provides preliminary data on the non-prescription usage of transdermal nicotine when purchased through pharmacies.

Pharmacokinetics of nicotine tartrate after single-dose liquid enema, oral, and intravenous administration

Ulcerative colitis is predominantly a disease of nonsmokers, and transdermal nicotine is therapeutic but often results in adverse reactions. Colonic administration of nicotine tartrate as a liquid enema could decrease systemic nicotine absorption and adverse reactions. The purpose of the current study was to determine the bioavailability and pharmacokinetic parameters of nicotine after administration by hydrophilic liquid enema (acidic and basic), hydrophobic liquid enema (acidic and basic), and by oral and intravenous routes. Thirty healthy volunteers received 45 micrograms nicotine base/kg (as nicotine tartrate) in one of five formulations (each n = 6): hydrophilic acidic liquid enema, hydrophilic basic liquid enema, hydrophobic acidic liquid enema, hydrophobic basic liquid enema, and oral solution. All participants also received 15 micrograms nicotine base/kg (as nicotine tartrate) intravenously during a separate study period. Serum concentrations of nicotine were determined by gas chromatography with mass spectrometry. The mean (+/-SD) bioavailabilities of nicotine after administration in the liquid enema formulations (hydrophilic acidic 17 +/- 18%, hydrophilic basic 16 +/- 16%, hydrophobic acidic 25 +/- 17%, hydrophobic basic 15 +/- 12%) were similar to the bioavailability of nicotine after administration by oral solution (20 +/- 25%). The bioavailabilities of nicotine for all five nonintravenous formulations were significantly less than for intravenous nicotine (100%). Serum concentrations of nicotine did not predict adverse reactions. Nicotine tartrate administered as either a liquid enema or as an oral solution had low bioavailability and was well tolerated. The therapeutic potential of nicotine tartrate liquid enemas, which can potentially limit toxicity by local (colonic) delivery of high doses of nicotine should be investigated in patients with left-sided ulcerative colitis.

Biomembrane permeation of nicotine: mechanistic studies with porcine mucosae and skin

In the present study, the permeation and partitioning of nicotine as a function of pH was investigated with various regions of skin and absorptive mucosae that were freshly excised from domestic pigs. As an ionizable compound (pKa values of 3.04 and 7.84), nicotine in solutions of different pH values provides a model for determining the influence of the charge status of a molecule on permeation. The permeation of nicotine across porcine mucosae and skin followed zero-order kinetics. The rate of permeation was dependent on donor solution pH and increased exponentially as the pH increased. With an exception of the nasal mucosa, which showed similar permeabilities for all species of nicotine, the permeability of nicotine across various skin and mucosal specimens was significantly higher (p < 0.001) for the un-ionized species (NN) than for the ionized species (NNH+, NH+NH+). It was also seen that un-ionized nicotine molecules were more permeable through absorptive mucosae (nasal, buccal, sublingual, and gingival) than through skin (abdominal, dorsal, thigh, and ear pinna). Partition studies were performed and the results further confirmed that biomembrane permeation of nicotine follows the pH-partition theory.

Intestinal permeability in the ileal pouch

BACKGROUND

Villous atrophy, mucin changes ('colonic metaplasia'), and chronic inflammation occur to varying degrees in all patients with ileal pouchanal anastomosis whereas acute inflammation (pouchitis) affects a subgroup of patients with prior ulcerative colitis.

AIM

To measure epithelial barrier function looking for possible functional adaptation in ileal 'pouch' mucosa.

PATIENTS

Patients with an ileal pouch prior to ileostomy closure (n = 12), functioning pouch (n = 14), pouchitis (n = 8), and ulcerative colitis (n = 12) were assessed.

METHODS

51Cr-EDTA was administered into the 'pouch' or rectum and urinary recovery over 24 hours was taken as an indication of permeability (barrier function). Histological analysis of 'pouch' biopsy specimens was undertaken.

RESULTS

Mucosal permeability is decreased from median 9.4% (range 5.4% to 39.1%) to 1.4% (range 0.38% to 2.2%) after ileostomy closure (p < 0.002) with levels being negatively correlated with two histological parameters of colonic metaplasia-mucin changes (p = 0.03) and villous atrophy (p = 0.05). Pouchitis was associated with increased permeability 5.9% (1.9% to 19.5%) compared with healthy 'pouch' 1.4% (0.35 to 2.2%) (p < 0.006).

CONCLUSION

Despite the presence of chronic inflammation in the mature 'pouch' functional adaptation with reduced permeability occurs in conjunction with colonic metaplasia.

Pharmacology of nicotine and its therapeutic use in smoking cessation and neurodegenerative disorders

During the last decade, nicotine has been used increasingly as an aid to smoking cessation and has been found to be a safe and efficacious treatment for the symptoms of nicotine withdrawal. This period has also seen significant advances in our understanding of the mechanisms underlying the psychopharmacological responses to nicotine, including, particularly, those that have been implicated in nicotine addiction. This paper reviews this decade of progress in the specific context of the therapeutic application of nicotine to the treatment of smoking cessation. Other putative future applications, particularly in the treatment of neurodegenerative disorders, are also reviewed.

Nanomolar concentrations of nicotine increase the release of [3H]dopamine from rat striatal synaptosomes

Nicotine stimulates the release of several neurotransmitters from brain tissue by acting on presynaptic nicotinic acetylcholine receptors (nAChR). In this study, an in vitro superfusion system was used to measure the nicotine-evoked release of [3H]dopamine (DA) from rat striatal synaptosomes. A 2-min exposure to micromolar nicotine produces a rapid increase in [3H]DA release. With continued exposure the response declines, apparently due to conversion of the nAChRs to a high-affinity desensitized conformation. In contrast, prolonged exposure to nanomolar concentrations of nicotine, while not producing an immediate response, leads to a gradual cumulative enhancement in [3H]DA release. This effect is calcium-dependent and blocked by the nicotinic antagonist, dihydro-beta-erythroidine. It is suggested that the gradual DA release in response to low concentrations of nicotine occurs as a result of either open channel properties of the desensitized receptor or an equilibrium between the high-affinity desensitized and active states of the nAChRs.

The transdermal nicotine patch: results of a randomised placebo-controlled trial

OBJECTIVES

To evaluate the efficacy of the transdermal nicotine patch as an aid to smoking cessation when used as an adjunct to a cognitive-behavioural group intervention and to assess the effectiveness of the patch in ameliorating withdrawal symptoms.

DESIGN AND SETTING

Double-blind placebo-controlled randomised trial with six months' follow-up of those who returned to the hospital-based outpatients smoking cessation clinic.

SUBJECTS

Three hundred and thirteen smokers recruited from the local community. Mean age was 42 years, 48% were male, mean cigarette consumption was 29 per day and mean duration of smoking was 24 years.

INTERVENTION

Cognitive-behavioural intervention delivered in a group context, two hours once a week over five weeks, self-help manual, and 24-hour daily nicotine patch treatment for 10 weeks.

MAIN OUTCOME MEASURES

Point prevalence abstinence at three and six months, and sustained cessation from end of treatment to six months, with biochemical validation (expired carbon monoxide). We examined the effectiveness of the nicotine patch in ameliorating specific withdrawal symptoms by self-report of degree of severity.

RESULTS

The active nicotine patch resulted in significantly higher biochemically confirmed abstinence rates when compared with placebo at three months (48% v. 21%) and at six months (33% v. 14%). Six-months' continuous abstinence rates were also significantly higher among the active nicotine group (25%) compared with placebo (12%). The most common adverse events among active patch users were sleep disturbance and local skin irritation. The nicotine patch reduced the severity of some withdrawal symptoms. A low level of dependence was the strongest predictor of three and six months' abstinence.

CONCLUSIONS

The transdermal nicotine patch is effective when used as an adjunct to a group cognitive-behavioural intervention and it provides relief from withdrawal symptoms associated with nicotine dependence.

Transdermal nicotine: reduction of smoking with minimal abuse liability

Cigarette consumption as well as the physiologic, performance and subjective effects of the nicotine patch were evaluated in ten subjects who smoked ad libitum while residing on a residential research ward for 30 days. Nicotine transdermal systems ("patches") delivering a total of 0, 22 or 44 mg per 24 h were applied daily at a constant dose during each 7-day condition; the order of dosing conditions was varied according to a randomized, double-blind, crossover design. Nicotine patches significantly but modestly reduced spontaneous smoking and significantly increased venous plasma nicotine levels. Self ratings of patch liking, satisfaction with cigarettes and the ability to identify the patch condition did not change as a function of the nicotine dose, indicating minimal abuse liability. There were no consistent changes in the puffing pattern measures; however, in all patch conditions, subjects with extensive histories of illicit drug use smoked cigarettes faster than subjects with histories of occasional drug use. Small changes in resting heart rate, pulse and blood pressure occurred when the nicotine patch was worn. Thus large changes in venous plasma nicotine levels engender only modest changes in ad libitum cigarette consumption, measures of abuse liability and cardiovascular effects. These findings are consistent with the notion that the addictive and toxic effects of nicotine are partially determined by the rate of drug administration.

Two studies of the clinical effectiveness of the nicotine patch with different counseling treatments

OBJECTIVE

To assess the effectiveness of transdermal nicotine therapy for smoking cessation and suppression of withdrawal severity in conjunction with two different adjuvant counseling treatments.

DESIGN

Two independent randomized placebo-controlled double-blind trials.

SETTING

Smoking cessation clinic.

SUBJECTS

Eighty-eight (study 1) and 112 (study 2) adult volunteers motivated to quit smoking.

INTERVENTIONS

Eight weeks of 22-mg transdermal nicotine therapy with group counseling (study 1); 4 weeks of 22 mg followed by 2 weeks of 11-mg transdermal nicotine therapy with brief individual counseling (study 2).

MAIN OUTCOME MEASURES

Modified point prevalence (7 consecutive days of nonsmoking) at the end of patch treatment and 6 months after treatment initiation was assessed by self-report and biochemically confirmed; survival analyses were also conducted for both studies to compare treatment efficacy. Also, we examined the impact of the nicotine patch on specific withdrawal symptoms (anger, anxiety, awakening, difficulty concentrating, depression, hunger, impatience, and craving).

RESULTS

Transdermal nicotine treatment produced higher cessation rates at the end of treatment than did placebo with both adjuvant counseling interventions: 59 percent vs 40 percent (p < 0.05 in study 1) and 37 percent vs 20 percent (p < 0.05 in study 2), respectively. Smoking cessation efficacy was maintained 6 months after initiation of treatment: 34 percent vs 21 percent (p = 0.08 in study 1) and 18 percent vs 7 percent (p = 0.05 in study 2). Survival analyses also revealed significant group differences in efficacy in both studies. Nicotine patches also suppressed a variety of withdrawal symptoms, including craving in the first weeks after patients quit smoking.

CONCLUSION

Transdermal nicotine effectively augments smoking cessation rates with two different types of counseling treatment. Overall, the nicotine patch approximately doubles the sustained rate of smoking cessation. Additionally, the nicotine patch provides relief from some tobacco withdrawal symptoms.

Smoking cessation methods: recommendations for health professionals. Advisory Group of the European School of Oncology

Smoking is the leading preventable cause of death. Approximately 40% of Europeans now smoke. Many smokers want to stop but do not make the attempt, and of those who try, most are unsuccessful. Primary care health providers can help their patients to stop by using brief behavioural and pharmacological interventions. Specialised smoking cessation clinics can support selected patients referred by primary care providers. This report reviews intervention techniques for health care providers, which, in combination with effective legislative and educational interventions, can significantly reduce the prevalence of smoking.

Transdermal nicotine in smoking cessation. A meta-analysis

A systematic search of the literature was made to identify relevant reports of clinical trials of transdermal nicotine, followed by detailed statistical analysis of the results to calculate a pooled estimate of the rate of smoking cessation. Both a fixed effect and a random effects model were used to calculate pooled estimates. The pooled odds ratio (OR) for short-term smoking cessation in favour of the transdermal patches was OR = 3.10. Using a random effects model, the risk difference (RD) in favour of the transdermal patches was RD = 0.25. The corresponding values for long-term cessation were OR = 2.26 and RD = 0.11. Skin irritation was a common adverse effect with incidence rates ranging up to about 70%. Nicotine transdermal patches were effective in promoting smoking cessation both in the short-term, with assessments at 3 to 10 weeks, and in the long-term, with assessment at 24 to 52 weeks. Long-term abstinence rates in subjects treated with nicotine patches for a few weeks remained higher than in subjects treated with placebo patches. Adverse effects were usually minor and transient, although subjects with a sensitive skin may find the applications intolerable. Further studies are required to confirm the value of nicotine patches in promoting smoking cessation in the absence of professional medical support and in general medical practices in the community.

Nicotine effects on eicosanoid formation and hemostatic function: comparison of transdermal nicotine and cigarette smoking

OBJECTIVES

The purpose of this study was to examine the possible role of nicotine in enhancing coagulation and to assess the potential cardiovascular toxicity of transdermal nicotine therapy for smoking cessation.

BACKGROUND

Cigarette smoking increases the risks of acute coronary events. A likely contributing mechanism is activation of coagulation. The role of nicotine in enhancing coagulability has not been resolved.

METHODS

We compared in a crossover study the effects of cigarette smoking, transdermal nicotine and placebo transdermal nicotine, each for 5 days, in 12 healthy smokers.

RESULTS

Cigarette smoking increased the urinary excretion of 11-dehydro-thromboxane B2 (reflecting thromboxane A2 generation) and increased plasma concentration of the platelet alpha-granule constituents, platelet factor 4 and beta-thromboglobulin, compared with placebo treatment, indicating in vivo platelet activation. Cigarette smoking was also associated with higher levels of fibrinogen in plasma. Transdermal nicotine produced plasma levels of nicotine in the same range as those during smoking but had no effect on thromboxane A2 metabolite excretion, platelet alpha-granule release or plasma fibrinogen, compared with placebo. Excretion of 2,3-dinor-6-keto-PGF1 alpha (reflecting prostacyclin generation) was not significantly influenced by any treatment. These results suggest that nicotine as such is not responsible for the platelet activation or elevation of plasma fibrinogen seen in smokers. However, we cannot exclude the possibility that intermittent bolus-like dosing of nicotine from cigarettes could have different effects from those produced by continually released transdermal nicotine. Other findings were that cigarette smoking and transdermal nicotine treatment were both associated with a higher white blood cell count compared with the placebo patch condition, suggesting a direct effect of nicotine to increase circulating white cells. Factor VII coagulant activity (VIIc) was significantly lower during cigarette smoking, than during either nicotine or placebo patch conditions.

CONCLUSIONS

Transdermal nicotine has less effect on platelet activation and catecholamine release than does cigarette smoking, and its use in smoking cessation treatment of patients with coronary heart disease is likely to be safer than cigarette smoking.

Nicotine transdermal systems

OBJECTIVE

To review the role of transdermal nicotine as an aid to smoking cessation.

DATA SOURCES

A MEDLINE search was performed that included clinical studies published in English involving transdermal nicotine; references used in those articles were screened for additional published information.

STUDY SELECTION

Published clinical trials were reviewed with particular emphasis on controlled trials that evaluated safety and efficacy.

DATA SYNTHESIS

Transdermal nicotine therapy has been shown to be a safe and effective pharmacologic aid in a smoking cessation program when used in conjunction with a psychologic or behavior support system. Habitrol, Nicoderm, Nicotrol, and PROSTEP differ in some characteristics (i.e., delivery systems, total nicotine content and amount absorbed, rate of delivery, recommended duration of application); however, the clinical implication of these differences has not been determined.

CONCLUSIONS

Transdermal nicotine is effective for patients who are motivated to quit smoking and receive concomitant behavior support.

Chemical analyses as validators in smoking cessation programs

This review addresses the use of chemical analyses to validate the smoking status of a participant in a smoking cessation program. Pharmacokinetic and chemical validation literature leads to the conclusion that chemical analyses are most reliably used to confirm abstinence from smoking rather than as quantitative measures of nicotine intake or smoking activity. Analytical methodologies used in smoking validation studies are reviewed with their advantages and disadvantages. Close collaboration of behavioral scientists and analytical chemists is encouraged to validate the smoking status of participants in a smoking cessation program.

Targeting heavy smokers in general practice: randomised controlled trial of transdermal nicotine patches

OBJECTIVES

(a) To evaluate the efficacy of transdermal nicotine patches as an aid to stopping smoking when used as an adjunct to brief advice and support in a general practice setting; (b) to see whether an increase in nicotine patch dosage enhances the rate of initial cessation.

DESIGN

Randomised double blind placebo controlled parallel group study with one year of follow up.

SETTING

30 general practices in 15 English counties.

SUBJECTS

600 dependent heavy smokers (> or = 15 cigarettes daily) who were well motivated to give up.

INTERVENTIONS

Brief general practitioner advice, booklet, and 16 hours per day patch treatment for 18 weeks with brief support and follow up at one, three, six, 12, 26, and 52 weeks.

MAIN OUTCOME MEASURES

Self reported complete abstinence for up to one year with biochemical validation at all follow up points.

RESULTS

Nicotine patches reduced the severity of craving and adverse mood changes in the first weeks of withdrawal and doubled the rate of initial cessation at week 3 (nicotine group 36% of patients (144/400), placebo group 16.5% of patients (33/200)) and of continuous abstinence throughout one year (nicotine group 9.3% (37), placebo group 5.0% (10)). A dose increase at week 1 among patients experiencing difficulty in quitting increased the proportion who achieved abstinence at week 3. There were no adverse systemic effects attributable to nicotine, but the incidence of moderate or severe local irritation or itching at the patch site was 16.4% (63 patients), compared with 3.8% (seven) with placebo.

CONCLUSION

Transdermal nicotine patches used as an adjunct to brief advice and support in a general practice setting are an effective aid to long term cessation of smoking in highly dependent smokers.

Recycling with nicotine patches in smoking cessation

The aim was to evaluate if recycling of failures from a smoking cessation study may be of value. The study comprised 126 smokers (50%) of 252 failures, from a double-blind smoking cessation trial with nicotine patch, who accepted recycling after 1 year. Subjects were allocated nicotine patches delivering 15, 20 or 25 mg of nicotine (over 16 hours) according to their base-line saliva cotinine concentrations in an open trial. The treatment period was 12 weeks followed by tapering over 6 weeks. The percentage of quitters after 3, 12, 26, and 52 weeks was 44, 20, 7 and 6%, respectively. After 26 weeks, all subjects had relapsed in the group previously treated with active nicotine patch compared with 12% abstainers in the previous placebo subjects. The sustained abstinence rate without slips after one year was 2%. Recycling does not seem to be of long-term clinical relevance in our set-up for subjects initially treated with nicotine, but of some value in subjects quitting without nicotine therapy initially.

Medication delivery in the short-bowel syndrome

Technologic advances such as total parenteral nutrition have prolonged the lives of individuals with short-bowel syndrome who previously would not have survived. However, the day-to-day management of these patients presents a significant challenge to those who take care of them. Providing medications on either an acute or chronic basis without the use of their central catheters is a difficult clinical problem. This article reviews the approach and methods of treating short-bowel patients on the basis of their individual circumstances and physiology.

Single- and multiple-dose pharmacokinetics of Nicoderm (Nicotine Transdermal System)

The pharmacokinetics and tolerability of single and multiple applications of Nicotine Transdermal Systems (NTS), designed to deliver 14 mg of nicotine per 24 hours, were investigated in 20 healthy adult male smokers. After a single application, mean Cmax and tmax for plasma nicotine were 12.2 ng/mL and 4.4 hours, respectively. Plasma nicotine concentrations rose rapidly and then remained steady between 12 and 24 hours after application. The apparent nicotine half-life (t1/2) after system removal was 3.2 hours. Steady state was attained by the second day of multiple application, and mean steady-state nicotine Cavg was 25% higher on day 5 compared with the first NTS application. Steady-state plasma cotinine was reached by the fourth day of multiple application and, as with nicotine, Cavg and Cmax increased, tmax decreased, and t1/2 did not change compared with single application. The mean ratios of cotinine-to-nicotine area under the curve (AUC) values for single and multiple NTS applications were 14.0 and 15.8, respectively. The pharmacokinetics of nicotine and cotinine were linear between single and multiple NTS applications. The nicotine transdermal systems were generally well tolerated.

Steady-state pharmacokinetics and dose relationship of nicotine delivered from Nicoderm (Nicotine Transdermal System)

An open-label, randomized, crossover study determined nicotine pharmacokinetics at steady state of a new Nicotine Transdermal System in 24 healthy adult male smokers. Three doses were each administered for 5 days: 7, 14 and 21 mg nicotine per day. Plasma nicotine concentrations reached steady state by the third day and were sustained throughout the 24-hour application periods. Mean steady-state nicotine and cotinine area under the curve (AUC0-24), maximum plasma concentration (Cmax), minimum plasma concentration (Cmin), average plasma concentration (Cavg), and total urinary cotinine were proportional to the dose of nicotine released in vitro from Nicotine Transdermal System. Time to reach peak concentration (tmax), half-life (t1/2), relative degree of fluctuation (DF) in steady-state plasma nicotine and cotinine concentrations, and renal cotinine clearance were similar for all three dosages, indicating linear pharmacokinetics and no change in nicotine metabolism with increasing dose. Findings from a second study also reflect the linear dose relationship for this Nicotine Transdermal System within the 7 to 21 mg/day dosage range. Bioequivalence based on the confidence interval test was demonstrated for a single application of Nicotine Transdermal System 21 mg/day and the same total dosage achieved by combined administration of Nicotine Transdermal System 7 mg/day plus Nicotine Transdermal System 14 mg/day, although there were small statistical differences. This Nicotine Transdermal System has a well-defined pharmacokinetic profile, with sustained plasma nicotine concentrations, and nicotine pharmacokinetics that are independent of the dose of this Nicotine Transdermal System.