Presentation on theme: "中枢兴奋药 Central Stimulants 北京协和医学院基础医学院药理学系 叶菜英. Central Stimulants Definition: Drugs that can stimulate the central nervous system. Classification: Cerebral."— Presentation transcript:
Central Stimulants Definition: Drugs that can stimulate the central nervous system. Classification: Cerebral cortex stimulation: Caffeine, Theophylline … Cerebrum and brain stem stimulation: Nikethamide, Dimefline and Lobeline. Spinal cord stimulation: Strychnine
Caffeine( 咖啡因 ) 【 Mechanism of Action 】 Inhibit phosphodiesterase, decrease the degradation of cAMP→cAMP↑ …… →physiological effect Central neuromodulator antagonist → effect of adenosine →block the inhibiting effect of adenosine on central nervous system→stimulate the central nervous system. Increasing intracellular free calcium Competitive antagonists of Benzodiazepine receptor, decrease the open frequency of Cl － channel→stimulate the central nervous system.
Caffeine 【 Pharmacologic properties and clinical application 】 CNS ： In small doses, it causes wakefulness, increases mental alertness, and decreases response times for simple motor task. Cardiovascular effects ： Small doses →stimulate vagus nerve→heart rate↓ Large doses→increase the sensitivity of heart rate→arrhythmia Vasoconstriction effects: use with Ergotamine, brain arteriectasis→treatment of migraine, usually compatible with antipyretic analgesic→cold, headache, hypertension headache （ APC 、 Somedon ）.
Lobeline ( 洛贝林 ) 【 Pharmacologic properties 】 Stimulate carotid body and aortic chemoreceptor, stimulate respiratory center reflectivity. Large doses Lobeline can stimulate medulla oblongata respiratory center directly. Stimulate sympathetic nerve→increase in the heart rate, BP↑ Take effect rapidly, hold time is short (several minutes). Lobeline is often used to improve respiratory depression which induced by neonatal asphyxia and pedo-infectious diseases, it also can improve respiratory failure which induced by drug intoxication and CO 2 intoxication. Adverse effect ： increase in the heart rate ， overdose→convulsion
Nikethamide( 尼可刹米 ) ( Coramine 可拉明 ) 【 Pharmacologic properties 】 Increase the stimulation of CNS, especially stimulate medulla oblongata respiratory center, carotid body and aortic chemoreceptor, and then, stimulate respiratory center reflectivity, increase the CO 2 sensitivity of CNS, accelerating and deepening breathing, improving respiratory function. The stimulate effect of cerebral cortex vasomotor center and spinal cord is weak. Take effect rapidly, hold time is short ， a single intravenous bolus can maintain 5 to 10 minutes.
Nikethamide （ Coramine ） Clinical application: various kinds of central respiratory depression (neonatal asphyxia, CO 2 intoxication ， drug intoxication). Adverse effects are rare. Overdose→BP↑ ， tachycardia, amyostasia and rigor, cough, vomiting, perspiration. Toxis→convulsion.
Central Stimulants 【 Clinical application 】 Application conditions of Respiratory Stimulants: trachea is smooth, and respiratory muscle is normal （ no obviously sputamentum retention and bronchospasm ）. Combination measures: etiological treatment inhaling O 2, artificial respiration. The holding time of central stimulants is short, so it should be used again and again. Prevent convulsion （ Overdose→ convulsion ）： several kinds of drug can be used taking turns, control doses strictly→→→