烟草依赖的药物治疗尼古丁替代疗法课件.ppt

* 很多人会认为，烟草依赖只是一种个人习惯而已，其实，烟草依赖不只是一种个人习惯，而是一种明确界定的慢性病。 1998年世界卫生组织决议将烟草依赖作为一种疾病列入国际疾病分类(ICD-10,F17.2) ，确认烟草是目前对人类健康的最大威胁。 烟草依赖的特点是无法克制的尼古丁觅求冲动，以及强迫性地、连续地使用尼古丁，以体验其带来的欣快感和愉悦感，并避免可能产生的戒断症状，实质就是尼古丁成瘾。 Key Point Nicotine addiction is a cycle which begins with nicotine binding to receptors in the brain causing the release of dopamine which in turn results in feelings of pleasure and calmness. Background The distribution of nicotine is very rapid. It can reach the brain within 10 to 20 seconds after inhaling cigarette smoke.1 The binding of nicotine to its relevant receptors results in the release of multiple neurotransmitters, most critically dopamine. The release of dopamine in the nucleus accumbens neurons is thought to play a critical role in the addictive nature of nicotine. This release of dopamine requires binding of nicotine to ?4?2 receptors.1,2 Absorption of cigarette smoke from the lungs is rapid and complete, producing with each inhalation a high concentration of arterial nicotine that reaches the brain within 10 to 16 seconds. Nicotine has a terminal half-life in blood of 2 hours. Smokers therefore experience a pattern of repetitive and transient high blood nicotine concentrations from each cigarette. Nicotine’s activation of acetylcholinergic receptors induces the release of dopamine in the nucleus accumbens. This is similar to the effect produced by other drugs of misuse, such as amphetamines and cocaine. The symptoms of nicotine withdrawal are a major barrier to smoking cessation. Smokers start to experience impairment of mood and performance within hours of their last cigarette. These effects are completely alleviated by smoking a cigarette. Withdrawal symptoms include irritability, restlessness, feeling miserable, impaired concentration, and increased appetite, as well as craving for cigarettes. Cravings, sometimes intense, can persist for many months. References Jarvis MJ. Why people smoke. BMJ. 2004;328:277-279. Picciotto MR, Zoli M, Chang