抗生素合理应用(全)讲解.ppt

5. 结核皮试阳性* 直径≥5mm定为阳性者见于：HIV，近期结核患者密切接触者，结核病愈后CXR持续者 ≥10mm定为阳性见于：来自结核病高发区的外来人口，静脉药瘾者，低收入人群 ≥15mm：均定为阳性 异烟肼 300 mg qd 6个月 （或900 mg 每周2次 12 个月)，使死于结核的危险性由超过6%降至接近于零 6. 患者遭遇性暴力 可给予环丙沙星 (500 mg) 或 头孢克肟 （400 mg）加阿奇霉素 (1g) 1次口服 并予乙肝免疫球蛋白 (0.06ml/kg IM) 谢 谢 Thank You * * 抗生素按杀菌活性可分成二类： 时间依赖型 浓度依赖型 * 时间依赖型的抗生素主要的一大类就是b -内酰胺类 (青霉素类、头孢菌素、氨曲南、碳烯类)，克林和大环(红、克、阿奇)、四环、链、万古，是目前临床上应用最多的一些抗生素 它有以下特点： 持续后效应-无或轻、中度 在MIC4-5倍时杀菌率即处于饱和 杀菌范围主要依赖于接触时间 血药浓度超过MIC时间是与临床疗效相关的主要参数 * 浓度依赖型的抗生素包括氨基糖苷类和喹诺酮类，甲硝唑 它有以下几个特点 投药目标达到最大药物接触，药物浓度越高，杀菌率及杀菌范围也越大 24小时AUC（浓度时间曲线下面积）/MIC、峰浓度/MIC是疗效相关的主要参数 * This slide represents key factors involved in antimicrobial therapy. Once the dose is administered, pharmacokinetic parameters then describe what happens to the drug once it enters the body. Absorption from the GI tract is essential for oral therapy. Once in the blood stream critical factors for success include distribution of the drug into the infected tissues. How long a drug remains in the blood stream is determined by half-life (metabolism or excretion) The distribution and metabolism of the drug can have an impact on safety (hepatic metabolites) or efficacy (urine excretion unchanged for UTI). The degree of protein binding can impact the microbiologic activity Pharmacodynamics represents the relationship between the pharmacologic activity (MIC) and pharmacokinetics (AUC or peak concentrations). The pharmacologic activity of an antibiotic can be defined by whether they are time-dependent, (effect can be predicted by time above the MIC, or concentration dependent - higher the concentration the greater the bacterial killing) as defined by peak:MIC or AUC:MIC ratios. In addition, post antibiotic effect (PAE) or the continued bacterial killing when the antibiotic blood level fall below the MIC can also impact efficacy. Pharmacologic effect can be determined by a decline in bacterial colony counts which is typically observed in in vitro models. Mortality rates in animal studies