《第4篇影响药物效应因素课件.ppt》由会员分享，可在线阅读，更多相关《第4篇影响药物效应因素课件.ppt（22页珍藏版）》请在三一办公上搜索。
1、Factors that Affect Drugs Effectiveness,Department of Pharmacology, School of Pharmacy, Liaoning University of Traditional Chinese Medicine,Drugs factors,IDose, and Physical nature of drugsFor instance, drug powder size, formulation, electrical charge, and shape. 剂量不同，同一药物对机体作用的强度也不一样。 例： 注射剂、片剂 不同剂
2、型吸收程度不同，同一剂型也因制剂工艺不同而不同.,Routes of administration 口服: 吸收慢而不规则； 注射: 不方便、经济与安全； 舌下与直肠：无首过效应,但吸收率不高； 吸入：适用于麻醉药和气管扩张药局部用药,给药时间、给药间隔时间及疗程 1、给药时间 A cycle of active and non-active periods in body determined by the internal mechanisms ad repeated about every 24 hours is called circadian rhythm (biological c
3、lock). The study of circadian rhythm of drug disposition is called Chronopharmacology 2、给药间隔时间 应用抗菌药治疗感染性疾病时尤为突出，因为血药浓度在有效和无效之间波动可导致细菌产生抗药性。 3、疗程 指为达到一定的治疗目的而连续用药的时间。,Sudden cardiac death parallels those of hypertension, heart muscle ischemia, angina, and heart attack - a 70% greater risk between th
4、e hours of 7 a.m. and 9 a.m., compared to the rest of the day.,Cushings syndrome (hypercortisolism) caused by hypothalamus producing corticotropin-releasing hormone (CRH), CRH stimulates the pituitary release of adrenocorticotropic hormone (ACTH) which stimulates the adrenal glands to produce cortis
5、ol,反复用药 1、耐受性快速耐受性：交叉耐受性： 2、耐药性,联合用药 药物相互作用(Drug interaction) Drug plasma protein bindingSynergism (potentiation) For instance, sulfamethoxazole and trimethoprim used in combination.药物配伍禁忌,药物在体内的相互作用包括药动学和药效学两个方面。 1、药动学方面 （1）妨碍吸收 （2）竞争血浆蛋白结合 （3）影响生物转化 （4）影响药物排泄,2、药效学方面（1）协同作用相加作用：如阿司匹林与对乙酰氨基酚合用，解热镇痛
6、作用增加增强作用：如磺胺甲噁唑与甲氧苄定合用，抗菌作用增加增敏作用：如可卡因抑制交感神经末梢对去甲肾上腺素的再摄取，出现去甲肾上腺素或肾上腺素作用增强（2）拮抗作用药理性拮抗：如纳洛酮拮抗吗啡的作用生理性拮抗：如组胺作用于H1受体，肾上腺素作用于受体化学性拮抗：如重金属或类金属中毒可用二硫基丙醇解救生化性拮抗：如苯巴比妥诱导肝药酶，使苯妥英钠等药代谢加速（3）无关作用,Individual factors,Individual variation can be congenital or acquired.I. Age Children Children are at the stage of
7、 developing organs, so the ability of drug hepatic metabolism and renal clearance of child and are lower than that adult. elderly For elderly, the organ functions, e.g., liver and kidney decreased, resulting in drug biotransformation in liver and drug excretion in kidney declined gradually.Pharmacol
8、ogical and adverse effects of a drug for both children and elderly are increased,II. Gender In Principle, there are no apparent differences between both genders response to drugs. However, (a) in menstruation, drugs affecting uterus contraction should be avoided to prevent from over bleeding; (b) in
9、 pregnancy, extreme carefulness should be taken for the safety of both mother and fetus; and (c) during lactation, attention should be paid to some drugs that excrete via the milk.,III、个体差异（1）高敏性：对药物反应特别敏感，很小量就能产生其他人常用量时的作用。（2）低敏性：对药物反应特别不敏感，需加大剂量才能有效（3）特异质反应药物代谢酶异常：慢乙酰化型、快乙酰化型非药物代谢酶异常：药物吸收障碍、高铁血红蛋白
10、缺乏,IV、种族 不同人种或民族的人群，对某些药物的反应会产生明显差异。大约有半数日本人和中国人肝内ALDH2缺乏，但在白种人和黑人中，未发现这种酶功能缺乏着。 Genetic factors The aim of pharmacogenetics is to study the influence of genetic difference and hereditary disease on the pharmacokinetics and pharmacodynmics of drugs.,V. Psychological factors Placebo effect: (a) The b
11、eneficial effect in a patient following a particular treatment that arises from the patients expectations concerning the treatment (non-specific placebo effect) rather than drug specific pharmacologic effects. Psychological factors not only include non-specific placebo effect but also include Patien
12、t-Doctor Interaction (relationship) which may influence patients mood and other subjective and objective effects controlled by autonomic nerves and hormones.,VI. Pathologic factors The liver is the main organ of drug metabolism. Hepatic dysfunction decreases drug metabolism, drug action will be prol
13、onged. However, some drugs are transformed to the active forms in the liver, in this situation, drug effects will be decreased. Renal excretion plays a key role in final drug elimination. Renal failure will result in drug accumulation in the body, prolonging its effect.,Cardiac disease Cardiac disea
14、se, by limiting blood flow to the liver, may depress the elimination of drugs whose metabolism is flow-limited and the clearance is perfusion-limited,其他因素,一、营养状态 营养不良： 高蛋白及低蛋白饮食： 禁食和饥饿：二、嗜好和环境 1、长期饮酒和吸烟 2、环境中存在多种化学物质 3、环境温度、湿度、噪音、通气条件等,练习题,联合应用两种药物，其总的作用大于各药单独作用的代数和，这种作用叫做：A、增强作用B、相加作用C、协同作用D、互补作用E、拮抗作用,A、药物引起的反应与个人体质有关，与用药剂量无关B、等量药物引起和一般病人相似但强度更高的药理效应或毒性C、用药一段时间后，病人对药物产生精神上的依赖，中断用药后，会出现主观上的不适D、长期用药后，产生了生理上的依赖，停药后出现了戒断症状E、长期用药后，需要逐渐增加用量，才能保持药效不减1、高敏性是：2、过敏性是：3、成瘾性是：4、耐受性是：,
