RESUMO
OBJECTIVES: To provide an overview of the complicity of British American Tobacco (BAT) in the illicit trade of cigarettes across the African continent in terms of rationale, supply routes and scale. METHODS: Analysis of internal BAT documents and industry publications. RESULTS: BAT has relied on illegal channels to supply markets across Africa since the 1980s. Available documents suggest smuggling has been an important component of BAT's market entry strategy in order to gain leverage in negotiating with governments for tax concessions, compete with other transnational tobacco companies, circumvent local import restrictions and unstable political and economic conditions and gain a market presence. BAT worked through distributors and local agents to exploit weak government capacity to gain substantial market share in major countries. CONCLUSIONS: Documents demonstrate that the complicity of BAT in cigarette smuggling extends to Africa, which includes many of the poorest countries in the world. This is in direct conflict with offers by the company to contribute to stronger international cooperation to tackle the illicit tobacco trade.
Assuntos
Crime , Países em Desenvolvimento , Indústria do Tabaco/organização & administração , África , Comércio , Humanos , Marketing/métodos , Fumar/economiaRESUMO
OBJECTIVES: To examine British American Tobacco and other tobacco industry support of the Eliminating Child Labour in Tobacco Growing Foundation. DESIGN: Analyses of internal tobacco industry documents and ethnographic data. RESULTS: British American Tobacco co-founded the Eliminating Child Labour in Tobacco Growing Foundation (ECLT) in October 2000 and launched its pilot project in Malawi. ECLT's initial projects were budgeted at US2.3 million dollars over four years. Labour unions and leaf dealers, through ECLT funds, have undertook modest efforts such as building schools, planting trees, and constructing shallow wells to address the use of child labour in tobacco farming. In stark contrast, the tobacco companies receive nearly US40 million dollars over four years in economic benefit through the use of unpaid child labour in Malawi during the same time. BAT's efforts to combat child labour in Malawi through ECLT was developed to support the company's "corporate social responsibility agenda" rather than accepting responsibility for taking meaningful steps to eradicate child labour in the Malawi tobacco sector. CONCLUSION: In Malawi, transnational tobacco companies are using child labour projects to enhance corporate reputations and distract public attention from how they profit from low wages and cheap tobacco.
Assuntos
Agricultura/normas , Proteção da Criança , Nicotiana , Responsabilidade Social , Indústria do Tabaco/normas , Criança , Pré-Escolar , Países em Desenvolvimento , Emprego/normas , Humanos , Sindicatos , Malaui , Relações PúblicasRESUMO
OBJECTIVE: To demonstrate that Philip Morris and British American Tobacco Company attempted to initiate a wide ranging campaign to undermine the success of the 8th World Conference on Tobacco or Health held in Buenos Aires, Argentina, in 1992. DATA SOURCES: Publicly available tobacco industry documents housed in Minneapolis, Minnesota, USA; Guilford, UK; on-line document websites; and telephone interviews with informed parties. STUDY SELECTION: Those documents determined to be relevant to the companies' campaigns against the 8th World Conference on Tobacco or Health. DATA EXTRACTION: Revision of chapter VIII of the July 2000 WHO report by a committee of experts, entitled: Tobacco company strategies to undermine tobacco control activities at the World Health Organization: report of the committee of experts on tobacco industry documents. DATA SYNTHESIS: Internal documents describe proposed media and science orientated campaigns developed by BAT, Philip Morris, and their consultants to divert attention away from the conference. RESULTS AND CONCLUSION: This work shows that the tobacco industry has the resources and vested interest to combat perceived threats in its regional operating markets, in this case its Latin American market. It is important for the worldwide public heath community to become aware of the numerous ways in which the tobacco industry and its front groups can work against international tobacco control meetings, even including the manipulation of or working with other public health groups to oppose tobacco control efforts. Future world conference planners and participants should be aware that the tobacco industry is likely to continue to employ such methodology. There is no reason to think that the industry is paying less attention to such conferences in the present or future. Rather, it is likely the industry will adopt and expand strategies that were successful while abandoning those that were not effective. Required disclosure of financial support by all participants at all tobacco scientific conferences is recommended. For the tobacco control community, we also recommend careful coalition building and networking with other public health groups on the ways tobacco is implicated in other public health issues.
Assuntos
Promoção da Saúde , Relações Interprofissionais , Propaganda , Prevenção do Hábito de Fumar , Indústria do Tabaco , Congressos como Assunto , Humanos , Manobras Políticas , Meios de Comunicação de Massa , Relações PúblicasRESUMO
OBJECTIVE: To describe smoking abstinence and fetal effects of pregnant smokers who received 8 weeks of nicotine patch therapy. METHODS: One-sample study of 21 pregnant women smoking > or = 15 cigarettes/day during their third trimester of pregnancy despite physician advice to stop. Nicotine patch therapy (22 mg/24 h) was initiated during the first day of a 4-day in-hospital study and continued for a total of 8 weeks. Subjects returned weekly until delivery, at 4 weeks after delivery, and at 6 and 12 months after patch therapy. Fetal growth and well-being were assessed using ultrasound examinations and non-stress tests. RESULTS: Eight of 21 subjects completed all 8 weeks of patch therapy according to the protocol. Five subjects (24%) discontinued using the nicotine patch, owing to adverse skin reactions. There were eight subjects (38%) who were biochemically confirmed abstinent from smoking at the time of delivery; of these, seven were continuously abstinent from the start of patch therapy. Centile weight for gestational age did not change significantly over time for 12 subjects with serial ultrasound measurements available at baseline, 4 weeks and 8 weeks following initiation of patch therapy. In all cases, non-stress tests remained reactive or became reassuring with observation. No significant preterm deliveries occurred (gestational ages of 36.3-41.1 weeks). Three infants suffered severe neonatal morbidity; however, these problems were unrelated to nicotine patch therapy. CONCLUSION: Nicotine patch therapy has potential benefit for pregnant smokers who continue to smoke despite physician advice to stop.
Assuntos
Nicotina/administração & dosagem , Resultado da Gravidez , Abandono do Hábito de Fumar/métodos , Administração Cutânea , Adulto , Desenvolvimento Embrionário e Fetal , Exantema/etiologia , Feminino , Sangue Fetal/química , Idade Gestacional , Humanos , Masculino , Nicotina/efeitos adversos , Nicotina/sangue , Trabalho de Parto Prematuro/epidemiologia , Gravidez , Ultrassonografia Pré-NatalRESUMO
BACKGROUND: Smoking relapse is common after successful pharmacologic treatment for smoking cessation. No previous studies have examined long-term drug therapy used expressly for prevention of smoking relapse. OBJECTIVE: To evaluate the efficacy of bupropion to prevent smoking relapse. DESIGN: Randomized, placebo-controlled trial. PARTICIPANTS: 784 healthy community volunteers who were motivated to quit smoking and who smoked at least 15 cigarettes per day. INTERVENTION: The participants received open-label, sustained-release bupropion, 300 mg/d, for 7 weeks. Participants who were abstinent throughout week 7 of open-label treatment were randomly assigned to receive bupropion, 300 mg/d, or placebo for 45 weeks and were subsequently followed for an additional year after the conclusion of the medication phase. Participants were briefly counseled at all follow-up visits. At the end of open-label bupropion treatment, 461 of 784 participants (58.8%) were abstinent from smoking. MEASUREMENT: Self-reported abstinence was confirmed by an expired air carbon monoxide concentration of 10 parts per million or less. RESULTS: The point prevalence of smoking abstinence was significantly higher in the bupropion group than in the placebo group at the end (week 52) of drug therapy (55.1% vs. 42.3%, respectively; P = 0.008) and at week 78 (47.7% vs. 37.7%; P = 0.034) but did not differ at the final (week 104) follow-up visit (41.6% vs. 40.0%). The median time to relapse was significantly greater for bupropion recipients than for placebo recipients (156 days vs. 65 days; P = 0.021). The continuous abstinence rate was higher in the bupropion group than in the placebo group at study week 24 (17 weeks after randomization) (52.3% vs. 42.3%; P = 0.037) but did not differ between groups after week 24. Weight gain was significantly less in the bupropion group than in the placebo group at study weeks 52 (3.8 kg vs. 5.6 kg; P = 0.002) and 104 (4.1 kg vs. 5.4 kg; P = 0.016). CONCLUSIONS: In persons who stopped smoking with 7 weeks of bupropion treatment, sustained-release bupropion for 12 months delayed smoking relapse and resulted in less weight gain.
Assuntos
Bupropiona/administração & dosagem , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar , Adulto , Bupropiona/efeitos adversos , Preparações de Ação Retardada , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Recidiva , Aumento de PesoRESUMO
BACKGROUND: Quit and Win is a community-wide stop smoking contest to help cigarette smokers stop smoking and educate the general public concerning smoking hazards. METHODS: All community residents, 15 years of age or older, were eligible to participate in either the stop smoking contest or the supporter contest. A random telephone survey to local households was conducted before and after the Quit and Win contest to assess the level of knowledge and attitude changes about smoking. RESULTS: Of the 304 smokers enrolled in the contest, 42% self-reported continuous tobacco abstinence for the 4-week contest period and 11% were abstinent at 1 year postcontest. Significant predictors for tobacco abstinence during the contest were formal education beyond high school, absence of other smokers in the household, having a support person enrolled in the support person contest, and the type of relationship that the support person had with their smoker. Survey results showed that this contest changed some local attitudes and increased general knowledge of smoking hazards. CONCLUSIONS: Community-wide stop smoking contests can be used to engage smokers and their support in the community and can be successful in reducing tobacco use.
Assuntos
Planejamento em Saúde Comunitária/métodos , Jogo de Azar , Promoção da Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde , Abandono do Hábito de Fumar/métodos , Adolescente , Adulto , Idoso , Análise de Variância , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , MinnesotaRESUMO
OBJECTIVES: This review details the tobacco industry's scientific campaign aimed against policies addressing environmental tobacco smoke (ETS) and efforts to undermine US regulatory agencies from approximately 1988 to 1993. METHODS: The public availability of more than 40 million internal, once-secret tobacco company documents allowed an unedited and historical look at tobacco industry strategies. RESULTS: The analysis showed that the tobacco industry went to great lengths to battle the ETS issue worldwide by camouflaging its involvement and creating an impression of legitimate, unbiased scientific research. CONCLUSIONS: There is a need for further international monitoring of industry-produced science and for significant improvements in tobacco document accessibility.
Assuntos
Política de Saúde , Apoio à Pesquisa como Assunto/organização & administração , Pesquisa/organização & administração , Indústria do Tabaco/organização & administração , Poluição por Fumaça de Tabaco/efeitos adversos , Poluição por Fumaça de Tabaco/prevenção & controle , Publicidade , Viés , Documentação , Política de Saúde/legislação & jurisprudência , Política de Saúde/tendências , Humanos , Serviços de Informação , Armazenamento e Recuperação da Informação , Internet , Ciência , Poluição por Fumaça de Tabaco/legislação & jurisprudência , Revelação da Verdade , Estados UnidosRESUMO
OBJECTIVE: To evaluate the tobacco use outcomes and baseline characteristics of adolescents treated for nicotine dependence. DESIGN: Retrospective cohort study. SETTING: Mayo Clinic Nicotine Dependence Center, Rochester, Minn. PATIENTS: Ninety-six adolescents (60 boys, 36 girls) receiving clinical services for treatment of nicotine dependence between January 1, 1988, and November 30, 1997. Their mean age was 15.6 years (range, 11-17 years), and 91.7% were white. INTERVENTION: The Nicotine Dependence Center intervention involves a 45-minute consultation with a nicotine dependence counselor. A treatment plan individualized to the patient's needs is then developed. Telephone follow-up is conducted at 6 and 12 months. As part of this study, a long-term follow-up was conducted by telephone at a mean of 5.3 years (range, 1.6-10.6 years) following the intervention. MAIN OUTCOME MEASURES: Self-reported 7-day point-prevalence abstinence from tobacco at 6 and 12 months, and 30-day point-prevalence tobacco abstinence at the long-term follow-up. RESULTS: The tobacco abstinence rates were 17.7% (17/96 patients) at 6 months, 7.3% (7/96 patients) at 12 months, and 11.5% (11/96 patients) at the long-term follow-up. A high proportion of the sample had smoking-related medical morbidity and psychiatric diagnoses documented in the medical record prior to or at the time of the intervention. CONCLUSIONS: Adolescents utilize the medical community to seek treatment for nicotine dependence. The 6-month tobacco abstinence rate is higher than the estimates of the natural history of smoking cessation in adolescents. Medical and psychiatric diagnoses are common in this population.
Assuntos
Terapia Cognitivo-Comportamental , Aconselhamento , Abandono do Hábito de Fumar , Fumar , Tabagismo/terapia , Adolescente , Comportamento do Adolescente , Criança , Terapia Cognitivo-Comportamental/métodos , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Telefone , Tabagismo/complicações , Tabagismo/tratamento farmacológico , Resultado do TratamentoRESUMO
OBJECTIVES: To identify predictors of smoking abstinence at the end of medication use that could assist in the optimal use of a sustained-release (SR) form of bupropion for treating cigarette smokers. DESIGN: A double-blind, placebo-controlled, dose-response trial. SETTING: Multicenter (three sites) study conducted in the United States. PARTICIPANTS: Six hundred fifteen healthy men and women (> or = 18 years of age) who were smoking > or = 15 cigarettes per day and who were motivated to stop smoking. INTERVENTION: Random assignment of patients to placebo or SR bupropion treatment, 100, 150, or 300 mg/d, for 7 weeks (total duration of study was 52 weeks: 7 weeks of treatment and 45 weeks of follow-up). MEASUREMENTS AND RESULTS: Logistic regression was used to identify predictors of abstinence at the end of the medication phase. Univariate predictors included the following: bupropion dose (p < 0.001); older age (p = 0.024); lower number of cigarettes smoked per day (cpd) (p < 0.001); lower Fagerström Tolerance Questionnaire score (p = 0.011); longest time previously abstinent that was < 24 h or > 4 weeks (p < 0.001); absence of other smokers in the household (p = 0.021); greater number of previous stop attempts (p = 0.019); and study site (p = 0.004). Multivariate predictors of abstinence at the end of the medication phase were the following: higher bupropion dose (p < 0.001); lower number of cpd (p < 0.001); longest time previously abstinent from smoking (p = 0.002); male gender (p = 0.014); and study site (p = 0.021). CONCLUSION: Bupropion SR therapy was effective in treating cigarette smokers independently of all other characteristics studied. Lower smoking rate, brief periods (ie, < 24 h) or long periods (ie, > 4 weeks) of abstinence with previous attempts to stop smoking, and male gender were predictive of better outcomes, independent of the dose of bupropion that was used.
Assuntos
Bupropiona/uso terapêutico , Inibidores da Captação de Dopamina/uso terapêutico , Abandono do Hábito de Fumar , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Indução de RemissãoRESUMO
OBJECTIVE: To compare smoking abstinence outcomes between smokers treated in a residential (inpatient) program and those treated in an outpatient program to determine if residential treatment was superior to outpatient treatment in smokers with moderate to severe nicotine dependence. PATIENTS AND METHODS: Patients treated in the residential nicotine dependence program at the Mayo Clinic, Rochester, Minn., between May 1, 1992, and January 31, 1996, were selected for this study. Each patient in the residential treatment group (n=146) was matched to 2 patients who received an outpatient nicotine dependence consultation by a trained counselor (n=292). Each patient was matched on age, sex, year seen, number of cigarettes smoked per day, longest previous abstinence, education, and marital status. Abstinence at 6 and 12 months was determined by self-report. For the purposes of analysis, each patient with missing outcome data was considered to be smoking. RESULTS: The 6-month abstinence rates for the residential group compared with the outpatient group were 45% and 26%, respectively (P<.001), and the 12-month abstinence rates were 45% and 23%, respectively (P<.001). After adjusting for matching variables that were not exactly matched (age, baseline number of cigarettes smoked per day, and longest previous abstinence) and the baseline variables, including education, age when started smoking, and degree of nicotine dependence, there was a significant effect of residential treatment on 6- and 12-month abstinence rates (P<.001). Odds ratio of 6-month abstinence in the residential group was 2.74 (95% confidence interval, 1.60-4.71; P<.001) and at 12 months was 3.03 (95% confidence interval, 1.74-5.27; P<.001). CONCLUSION: Residential treatment for tobacco dependence is superior to outpatient treatment in some smokers who are moderately to severely nicotine dependent.
Assuntos
Assistência Ambulatorial , Abandono do Hábito de Fumar/métodos , Centros de Tratamento de Abuso de Substâncias , Tabagismo/terapia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Minnesota , Resultado do TratamentoRESUMO
This prospective study assessed the relationship between current tobacco use and history of an alcohol problem to health status in hospitalized patients. Factors associated with current tobacco use and history of an alcohol problem were also evaluated. Data were collected using a self-administered survey distributed by nursing staff to adult inpatients registered on April 27, 1994 at the Mayo Clinic, Rochester, Minnesota affiliated hospitals. Respondents (N = 589, 45% female) were classified into 4 subgroups based on current tobacco use status and history of an alcohol problem: (a) current tobacco use only (n = 94, 16%); (b) history of an alcohol problem only (n = 30, 5%); (c) both (n = 27, 5%); or (d) neither (n = 438, 74%). Patients with both current tobacco use and an alcohol problem history reported markedly lower scores on health status measures of general and mental health compared to the other three subgroups. Moreover, current tobacco use and history of an alcohol problem were each associated with increased psychological distress. Current tobacco use was predictive of a history of an alcohol problem and vice versa.
Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Nível de Saúde , Fumar/efeitos adversos , Adulto , Idoso , Feminino , Inquéritos Epidemiológicos , Hospitalização , Humanos , Masculino , Anamnese , Pessoa de Meia-Idade , Fatores de Risco , Estresse PsicológicoRESUMO
Nicotine dependence is characterized by periods of relapse and remission. Health care workers can have a pivotal role in the treatment of nicotine dependence. Smokers should be identified and categorized based on their readiness to change. Smokers who are preparing to stop smoking should be given multicomponent therapy in a step-care approach using behavioral treatment, addiction treatment, pharmacotherapy, and techniques of relapse prevention. Pharmacotherapies approved by the Food and Drug Administration for smoking interventions include sustained-release bupropion, nicotine gum, the nicotine inhaler, nicotine nasal spray, and nicotine patches.
Assuntos
Abandono do Hábito de Fumar/métodos , Tabagismo/terapia , Adaptação Psicológica , Antidepressivos/uso terapêutico , Terapia Comportamental/métodos , Terapia Combinada , Humanos , Nicotina/uso terapêutico , Abandono do Hábito de Fumar/psicologia , Tabagismo/psicologiaRESUMO
The mesolimbic dopamine system is thought to be a critical substrate for drugs of addiction including nicotine. Since dopamine may play a critical role in mediating the reinforcing effects of nicotine, we hypothesized that administering levodopa in its therapeutic form (carbidopa/levodopa) might be effective for smoking cessation by replacing the effects of dopamine that smokers may seek during smoking. A pilot open-label study using carbidopa/levodopa for smokers wanting to stop smoking was carried out at the Mayo Clinic Nicotine Research Center, Rochester, MN. The dosing schedule was one tablet TID for 1 week, 1 1/2 tablets TID for 1 week, then two tablets TID for 6 weeks. Each tablet contained 25 mg of carbidopa and 100 mg of levodopa. The subjects were 40 adult smokers smoking > or = 20 cigarettes per day for 3 or more years. Self-reported abstinence from smoking was confirmed by expired air CO level of < or = 8 ppm. Nicotine withdrawal symptoms were assessed at baseline and daily during the medication phase. Smoking abstinence rates and withdrawal symptom relief were compared to the placebo (n = 153) arm of a previously reported bupropion smoking cessation trial. The biochemically confirmed, 7-day point-prevalence smoking abstinence rate at the end of carbidopa/levodopa treatment was 20.0% versus 19.0% for the placebo group (p > 0.10), and 12.5% of the carbidopa/levodopa group were abstinent versus 15.7% for the placebo group (p > 0.10) at 6 months. Subjects from both studies had significant increases in withdrawal scores from baseline, but there were no significant differences between the two groups at any time period. We found no differences in smoking abstinence rates or nicotine withdrawal symptom relief in smokers receiving carbidopa/levodopa compared to placebo. Despite the theoretical reasons why carbidopa/levodopa might be effective as a pharmacological adjunct in treating smokers, it was not observed in this group of smokers at this dose.
Assuntos
Carbidopa/uso terapêutico , Dopaminérgicos/uso terapêutico , Levodopa/uso terapêutico , Abandono do Hábito de Fumar/métodos , Adulto , Monóxido de Carbono/metabolismo , Quimioterapia Combinada , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Projetos PilotoRESUMO
Effects of nicotine on arterial endothelium-dependent relaxations mediated by nitric oxide are controversial. Experiments were designed to test the hypothesis that nicotine can directly alter activity of endothelial nitric-oxide synthase (eNOS). NOS from aortic endothelial cells of untreated dogs and recombinant eNOS, neuronal NOS, and inducible NOS were used for these experiments. NOS activity was determined as conversion of L-[(3)H]arginine to L-[(3)H]citrulline in the absence or presence of nicotine (10(-7)-10(-3) M) in vitro. In separate assays, concentrations of cofactors NADPH, FAD, and tetrahydrobioprotein were reduced by half to assess for possible interaction with nicotine. With enzyme from aortic endothelial cells, total and calcium-dependent accumulation of citrulline increased by 30% in the presence of 10(-5) M nicotine. Nicotine dose dependently also increased citrulline accumulation by recombinant eNOS and neuronal NOS but not inducible NOS. Effects of nicotine on accumulation of citrulline by isolated eNOS and recombinant eNOS were further modulated by changes in the concentration of NADPH in the incubation solution. Our data demonstrate a significant effect of nicotine on eNOS-mediated citrulline accumulation. These results suggest that effects of nicotine on production of nitric oxide may depend on NADPH or oxygen radical interactions with NOS and thus may explain, in part, inconsistent findings of changes in production of endothelium-derived nitric oxide with nicotine administration.
Assuntos
Biopterinas/análogos & derivados , Nicotina/farmacologia , Óxido Nítrico Sintase/metabolismo , Animais , Aorta Torácica/enzimologia , Arginina/metabolismo , Biopterinas/metabolismo , Biopterinas/farmacologia , Citrulina/metabolismo , Cães , Endotélio Vascular/enzimologia , Flavina-Adenina Dinucleotídeo/metabolismo , Flavina-Adenina Dinucleotídeo/farmacologia , Masculino , NADP/metabolismo , NADP/farmacologia , Óxido Nítrico Sintase/isolamento & purificação , Óxido Nítrico Sintase Tipo I , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Proteínas Recombinantes/metabolismoRESUMO
Nicotine patches are available as an over-the-counter medication for aid in smoking cessation. This study was designed to determine how nicotine patch therapy over time and dose ranges used in smoking cessation programs in humans affects endothelium-dependent relaxations. Dogs were treated with nicotine patches (11, 22, or 44 mg/day) for 2 and 5 wk. Circulating nicotine and oxidized products of nitric oxide (NOx) were measured. Coronary arteries were prepared for measurement of isometric force and aortic endothelial cells were prepared for measurement of mRNA or NO synthase (NOS) activity. Circulating nicotine increased with increasing concentrations of nicotine patches. After 5 wk of treatment with 22 mg/day patches, circulating NOx was reduced but NOS activity was increased. NOS mRNA was similar among groups. Only after 5 wk of treatment with 22 mg/day patches were endothelium-dependent relaxations reduced to alpha(2)-adrenergic agonists, ADP, and the calcium ionophore A-23187. These results suggest a time and biphasic dose effect of nicotine treatment on endothelium-dependent responses that may be related to bioavailability of NO. This complex relationship of duration and dose of nicotine treatment may explain, in part, discrepancies in effects of nicotine on endothelium-dependent responses.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Nicotina/administração & dosagem , Difosfato de Adenosina/farmacologia , Administração Cutânea , Animais , Aorta/enzimologia , Calcimicina/farmacologia , Cálcio/fisiologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/fisiologia , Cotinina/sangue , Cães , Relação Dose-Resposta a Droga , Endotélio Vascular/enzimologia , Inibidores Enzimáticos/farmacologia , Técnicas In Vitro , Ionóforos/farmacologia , Masculino , Nicotina/sangue , Nicotina/farmacologia , Nitratos/sangue , Óxido Nítrico Sintase/metabolismo , Nitritos/sangue , RNA Mensageiro/metabolismo , Fatores de Tempo , Vasodilatação/efeitos dos fármacos , ômega-N-Metilarginina/farmacologiaRESUMO
Smoking is a major risk factor for failure of coronary artery bypass grafts (CABG). Experiments were designed to determine effects of transdermal nicotine, independent of smoking, on structure and function of CABG. Saphenous veins were placed as CABG in untreated dogs (control) or in dogs treated with transdermal nicotine (one 11-mg or two 22-mg patches/day) for 5 wk. Serum nicotine and plasma nitric oxide were measured. Grafts were removed and prepared for organ chamber studies and histology. Serum nicotine averaged 12.1 and 118.7 ng/ml in the 11 mg/day and 44 mg/day groups, respectively. Plasma nitric oxide was higher in dogs treated with 11 mg/day doses compared with controls. In organ chamber studies, endothelium-dependent relaxations to thrombin and A-23187 and endothelium-independent relaxations to nitric oxide were greatest in grafts from dogs treated with 11 mg/day doses. Intimal thickness of the grafts were similar among groups. However, staining for bone sialoprotein was increased in the media of grafts from the 11 mg/day treatment group. These data suggest that transdermal nicotine in doses comparable and double to those used for conventional smoking cessation treatment in humans does not adversely affect early patency of canine CABG up to 4 wk postoperatively. Transdermal nicotine, however, may increase production of and response to nitric oxide in bypass grafts.
Assuntos
Ponte de Artéria Coronária , Nicotina/farmacologia , Veia Safena/efeitos dos fármacos , Veia Safena/transplante , Actinas/metabolismo , Administração Cutânea , Animais , Calcimicina/farmacologia , Cotinina/sangue , Desmina/metabolismo , Cultura em Câmaras de Difusão , Cães , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Sialoproteína de Ligação à Integrina , Ionóforos/farmacologia , Masculino , Nicotina/sangue , Nitratos/sangue , Óxido Nítrico/farmacologia , Nitritos/sangue , Veia Safena/metabolismo , Sialoglicoproteínas/metabolismo , Trombina/farmacologia , VasodilataçãoRESUMO
Experiments were designed to determine the effects of nicotine treatment on the functions of saphenous veins used for coronary artery bypass grafts in dogs. Dogs received either no treatment or transdermal nicotine for 5 weeks at doses of 11 mg, 22 mg or 44 mg/day. Saphenous veins were removed and suspended for the measurement of isometric force in organ chambers. Endothelium was removed mechanically from some rings. N(G)-mono-methyl-L-arginine (L-NMMA; 10(-4) M) was used to inhibit the production of nitric oxide. Contractions to alpha2-adrenergic stimulation were decreased in veins from dogs treated with a 22-mg/day dose of transdermal nicotine. In addition, endothelium-dependent relaxations to adenosine-diphosphate (10(-8)-10(-4) M) and the calcium ionophore A23,187 (10(-8)-10(-6) M) were decreased in veins from dogs with a 22-mg/day dose and increased in veins from dogs treated with a 44-mg/day dose. These relaxations were inhibited by L-NMMA. Plasma concentrations of oxidized products of nitric oxide were decreased only in dogs treated with 22 mg/day of nicotine. The relaxation of rings without endothelium (direct response on the smooth muscle) to nitric oxide were not altered by nicotine treatment. These results suggest that the short-term treatment of dogs with intermediate (22 mg/day) but not low (11 mg/day) or high (44 mg/day) doses of transdermal nicotine decreases the endothelial function of veins used for coronary artery bypass grafts. Therefore, changes in plasma products of nitric oxide and endothelium-dependent relaxations mediated by nitric oxide are related to the dose of nicotine treatment.
Assuntos
Contração Isométrica/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Nicotina/farmacologia , Veia Safena/fisiologia , Administração Cutânea , Agonistas alfa-Adrenérgicos/farmacologia , Animais , Tartarato de Brimonidina , Calcimicina/farmacologia , Cães , Relação Dose-Resposta a Droga , Endotélio Vascular/fisiologia , Técnicas In Vitro , Masculino , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Nicotina/administração & dosagem , Nicotina/sangue , Óxido Nítrico/sangue , Cloreto de Potássio/farmacologia , Quinoxalinas/farmacologia , Veia Safena/efeitos dos fármacos , ômega-N-Metilarginina/farmacologiaRESUMO
OBJECTIVES: To determine the efficacy of nicotine patch therapy in adolescents who want to stop smoking and to assess biochemical markers of smoking and nicotine intake. DESIGN: Nonrandomized, open-label trial using a 15 mg/16 h patch. SETTING: Two midwestern cities. SUBJECTS: One hundred one adolescents aged 13 through 17 years smoking at least 10 cigarettes per day (cpd). INTERVENTION: Six weeks of nicotine patch therapy and follow-up visits at 12 weeks and 6 months. MAIN OUTCOME MEASURES: Self-reported smoking abstinence verified by expired-air carbon monoxide (CO) level of no more than 8 ppm, nicotine withdrawal symptoms, and plasma cotinine level. RESULTS: Forty-one participants were female (mean [+/- SD] age, 16.5 [+/- 1.1] years). Median baseline smoking rate was 20.0 cpd (range, 10-40 cpd). Biochemically confirmed point prevalence smoking abstinence was 10.9% (11/101) at 6 weeks and 5.0% (5/101) at 6 months. The mean (+/- SD) plasma cotinine level at baseline was 1510.9 +/- 732.7 nmol/L; for nonsmoking subjects at weeks 3 and 6, 607.8 +/- 386.2 and 710.0 +/- 772.5 nmol/L, respectively. Plasma cotinine levels were correlated with CO levels at baseline (r = 0.27; P = .006), week 3 (r = 0.34; P = .004), and week 6 (r = 0.26; P = .03) and with mean cigarettes smoked per day during weeks 3 (r = 0.24; P = .04) and 6 (r = 0.30; P = .02). Mean smoking rates decreased significantly during the study, an effect that lessened at 12 weeks and 6 months. CONCLUSIONS: Nicotine patch therapy plus minimal behavioral intervention does not appear to be effective for treatment of adolescent smokers. Plasma cotinine and CO levels appear to be valid measures of smoking rates during the cessation process, but not at baseline. Smoking rates were reduced throughout the study. Additional pharmacological and behavioral treatments should be considered in adolescent smokers.
Assuntos
Nicotina/administração & dosagem , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar , Administração Cutânea , Adolescente , Monóxido de Carbono/análise , Cotinina/sangue , Feminino , Seguimentos , Humanos , Masculino , Fumar/epidemiologia , Síndrome de Abstinência a Substâncias/prevenção & controle , Fatores de TempoRESUMO
The aim of the study was to determine if smoking reduction using a nicotine inhaler in heavy cigarette smokers who wanted to reduce but not stop smoking results in decreased levels of known biomarkers of harm. The study design was a one-sample within-subject comparative open-label study of 23 (10 male and 13 female) subjects using a nicotine inhaler to reduce smoking, with follow-up at 24 weeks. A structured protocol was used with a smoking-reduction schedule from 40 or more cigarettes per day to 10 cigarettes per day by week 9. Behavioral counseling was provided by a research assistant and ad lib use of the nicotine inhaler for 12 weeks was permitted. Blood thiocyanate, cotinine, 4-aminobiphenyl hemoglobin adducts; urine NNAL and NNAL-glucuronide; and expired air carbon monoxide were measured. On average, the subjects were able to reduce their smoking by over 50% at week 12, but only two were able to reduce to 10 cigarettes per day. The reported reduction in smoking was not associated with a consistent reduction in the biomarkers. There was no reduction in the NNAL, 4-aminobiphenyl hemoglobin adducts nor carbon monoxide levels of expired air. There was a significant reduction of NNAL-glucuronide and the sum of NNAL and NNAL-glucuronide but only at week 24. Thiocyanate levels increased. Before widely promoting harm reduction as a treatment strategy for heavy smokers, more research needs to be performed to prove conclusively that such smokers who want to reduce but not stop can actually reduce and maintain their smoking rate at a level which is likely to reduce harm. It also needs to be determined whether a reduction in the smoking rate translates into reduction of harm. At the present, for heavy smokers, an abstinence approach seems to be more scientifically sound.