Sedative and hypnotic [hip‘nɔtik] drugs 镇静催眠药

1 Introduction Definition Sedative ['sedətɪv]镇静药： to treat anxiety disorder Hypnotic [hip‘nɔtik] 催眠药： to treat sleep disorder

Benzodiazepines [benzəudai'æzəpi:ns] （BDZs, 苯二氮卓类） Diazepam [daɪ‘æzəpæm] 地西泮，安定 Classification 1 Short acting (T1/2<6 hours): Triazolam（三唑仑), Estazolam (艾司唑仑) 2 Intermediate acting (T1/2:6-20 hours): Lorazepam (劳拉西泮), Nitrazepam (硝基安定) 3 Long acting (T1/2>24 hours): Diazepam (地西泮)

A model of the GABAA receptor-chloride ion channel macromolecular complex γ-Aminobutyric acid (GABA, γ-氨基丁酸) released from nerve terminals→ binds to GABAA receptor→ receptor activation →Cl- channel opened → increase Cl- conductance of the neuronal membrane →postsynaptic [,pəustsi'næptik]突触后的 membrane hyperpolarization ['haipə,pəulərai'zeiʃən] 超极化→potentiating the inhibitory effect of GABA on the postsynaptic cells.

Mechanism of action: BDZs bind to the site (γ-subunit) on GABAA receptors, → increasing the affinity for GABA (to α, β subuit), → resulting in an increased opening frequency of these ligand-gated Cl- channels, → potentiating the inhibitory effect of GABA on the postsynaptic cells.

Pharmacodynamics of benzodiazepines： 1 Anxiolytic [æŋ,zaiə‘litik]抗焦虑的 action； 2 Sedative and Hypnotic action； 3 Anticonvulsant [,æntɪkən'vʌls(ə)nt]抗惊厥的 action； 4 Antiepileptic [‘ænti,epi’leptik]抗癫痫的 action 5 Muscle relaxation

Therapeutic Uses: 1. Anxiety 2. Insomnia [ɪn'sɑmnɪə]失眠 3. Preoperative sedation 4. Status epilepticus [ɛpɪˈlɛptɪkəs]癫痫持续状态 5. Convulsion [kən‘vʌlʃən] 惊厥, 抽搐

Adverse reactions Drowsiness(嗜睡), ataxia ([ə'tæksɪə]共济失调), reduced psychomotor [,saɪkəʊ'məʊtə] performance (精神运动协调能力下降) Dependence (依赖性) Withdrawal syndrome (撤药综合征) including rebound anxiety and insomnia, tremulousness and twitching [‘twitʃiŋ]抽搐 (反跳性焦虑、失眠、震颤、抽搐)。

Supplementary reading Insomnia is one of the most common complaints in general medical practice, and its treatment is predicated on proper diagnosis. Although the precise function of sleep is not known, adequate sleep improves the quality of daytime wakefulness, and hypnotics should be used judiciously [dʒu:'diʃəsli]明智地to avoid its impairment. A number of pharmacological agents are available for the treatment of insomnia. The "perfect" hypnotic would allow sleep to occur with normal sleep architecture rather than produce a pharmacologically altered sleep pattern. It would not cause next-day effects, either of rebound anxiety or of continued sedation. It would not interact with other medications. It could be used chronically without causing dependence or rebound insomnia on discontinuation. Regular moderate exercise meets these criteria but often is not effective by itself, and many patients may not be able to exercise. However, even small amounts of exercise often are effective in promoting sleep. Controversy争论in the management of insomnia revolves around two issues: pharmacological versus nonpharmacological treatment and the use of short-acting versus long-acting hypnotics. The side effects of hypnotic medications must be weighed against the sequelae [sɪ'kwiːliː]后遗症of chronic insomnia, which include a fourfold increase in serious accidents. Two aspects of the management of insomnia traditionally have been underappreciated: a search for specific medical causes and the use of nonpharmacological treatments. In addition to appropriate pharmacological treatment, the management of insomnia should correct identifiable [aɪdentɪ'fæɪəb(ə)l] 可辨认的causes, address inadequate sleep hygiene ['haɪdʒiːn]卫生学, eliminate performance anxiety related to falling asleep, provide entrainment [in'treinmənt]生物的周期转换of the biological clock so that maximum sleepiness occurs at the hour of attempted sleep, and suppress the use of alcohol and OTC sleep medications.

大纲要求 熟悉常用镇静催眠药的分类。 掌握苯二氮䓬类药物的作用、用途和不良反应。 熟悉巴比妥类药物的作用、用途、不良反应及中毒的解救原则。

Glossary Sedative Hypnotic Anxiolytic Anticonvulsant Antiepileptic Insomnia Convulsion Drowsiness Ataxia Dependence Withdrawal syndrome