09.镇静催眠药——山东大学药理学英文课件.ppt

Section 2 Barbiturates Pharmacokinetics Absorbed easily following po, im Duration of action of babiturates depends on degree of lipid solubility. Thiopental: redistribution Pharmacokinetics C.Biotransformation and excretion Metabolites lack activity Drugs with high lipophilicity: liver metabolism Drugs with low lipophilicity: kidney excretion Alkalinization of urine promotes excretion of babiturates. Phenobarbital intoxication: alkalinization of the urine Mechanisms ↑GABAergic inhibition(↑duration of Cl- channel opening) GABA mimetic(high dose) Inhibit exicitatory neurotransmitter Pharmacological Effects and Uses Sedation and hypnosis Anticonvulsant effects Anesthesia and administration pre-anesthesia thiopental（硫喷妥钠） Enhance the effects of other CNS depressants Adverse Drug Reactions After effect Tolerance and dependence Inhibition of respiration function Hepatic enzyme induction Adverse Drug Reactions Poisoning An overdose can result in coma, severe respiratory depression. supporting respiration and circulation,purging the stomach Alkalization of the urine often aids in the elimination of phenobarbital. Section 3 Chloral hydrate （水合氯醛） Hypnosis No influence on REM Anticonvulsant effects Irritation to mucous membrane Inhibit cardiac contractility Buspirone Uses:relief of anxiety Mechanism: a partial agonist at brain 5-HT1A-R Advantages: no sedative-hypnotic effects no psychomotor impairment no tolerance and dependence Melatonin（褪黑素） Clinical uses of sedative-hypnotics.  For relief of anxiety For insomnia For sedation and amnesia before medical and surgical procedures For treatment of epilepsy and seizure states As a component of balanced anesthesia (intravenous administration) For control of ethanol or other sedative-hypnotic withdrawal states For muscle r