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Antimicrobial drugs in Respiratory Infection Huifang Tang Department of pharmacology Zhejiang University, school of medicine [email protected] Introduction The key disorders of respiratory system: 1. Disorders of the upper respiratory tract ( 上 呼 吸 道 感 染 ) : rhinitis( 鼻 炎 ), tonsillitis( 扁 桃 体 炎 ), angina( 咽 峡 炎 ), laryngitis(喉炎), cold(感冒), etc. ; 病原体:90%病毒(鼻病毒、呼吸道合胞病毒、 腺病毒、流感病毒、副流感病毒、SARS) 10%细菌 2. Disorders of the lower respiratory tract(下呼吸道感 染): Bronchitis(支气管炎), Pneumonia(肺炎); 病原体:70-80%细菌 G+:肺炎链球菌、金黄色葡萄球菌; G-: 肺炎克雷伯杆菌、流感嗜血杆菌、绿脓杆菌、 大肠杆菌、变形杆菌; 厌氧杆菌:棒状杆菌、梭形杆菌 病毒、真菌、原虫、支原体、衣原体 院外获得性下呼吸道感染以革兰氏阳性球菌为主(主要为肺炎球菌) ,其次 为革兰氏阴性杆菌(最常见的为肺炎克雷伯杆菌) 。 院内获得性感染约 60%为革兰氏阴性杆菌,其中最多的是绿脓杆菌。 3.Chronic obstructive pulmonary disease (COPD, 慢性阻塞性肺疾病, 慢阻肺); 4.Asthma(支气管哮喘, 哮喘); 5.Neoplasma: nasopharyngeal carcinoma (鼻烟 癌), lung carcinoma(肺癌), etc. 6.Pulmonary tuberculosis (肺结核, PTB) Drugs for respiratory infections Part1 Antiviral drugs(抗病毒药) Part2 Antibacterial drugs(抗菌药) Part3 Antifungal drugs(抗真菌药) Part1 Antiviral drugs (抗病毒药) 病毒侵入人体的过程 病毒吸附侵入 (attachment & penetration) 病毒脱壳 (uncoating) 合成 核酸多聚酶 合成病毒 核酸\蛋白质 病毒颗粒 装配成熟 (assembly) 从细胞内 释放(release) Anti-influenza virus agents 金刚烷胺 金刚乙胺 血凝素 阻断M2蛋白 阻止病毒脱壳 及其RNA的释放 利巴韦林 抑制 核苷酸合成 奥司他韦 扎那米韦 选择性NA结合 抑制病毒 脱颗粒和扩散 神经氨酸酶 Anti-influenza virus agents Neuraminidase(神经氨酸酶,NA) inhibitors --influenza A &B Oseltamivir(奥司他韦): oral zanamivir(扎那米韦): intravenous, inhaled Peramivir (帕拉米韦): intravenous, Laninamivir(拉尼米韦): inhaled Influenza A neuraminidases form two groups on phylogenetic analysis: group 1 (N1, N4, N5, and N8) and group 2 (N2, N3, N6, N7, and N9). Circulating influenza viruses including avian influenzas H7N9 and H5N1 are susceptible to neuraminidase inhibitors, and ovesrvational clinical data show reduced mortality with timely oseltamivir therapy in H5N1 disease. M2蛋白抑制剂--influenza A Amantadine(金刚烷胺) Rimantadine (金刚乙胺) Most circulating or threatening influenza viruses at present are adamantane-resistant, including avian A H7N9, pandemic H1N1, avian H10N8, and seasonal H3N2 viruses adamantane resistance is variable in avian H5N1 viruses, and many isolates have been susceptible. a dual regimen of an adamantane and neuraminidase inhibitor would be a reasonable initial treatment regimen for serious influenza when the infecting strain is probably susceptible to both drug classes. 广谱抗病毒药--DNA &RNA viurs Ribavirin(利巴韦林, virazole病毒唑): Aerosolised and intravenous Combinations of ribavirin with neuraminidase inhibitors have shown variable interactions. Peramivir and ribavirin showed synergistic activity for an H1N1 virus in vitro and enhanced survival effects when given orally in combination compared with suboptimum doses of either agent. Several oseltamivir and ribavirin dose combinations increased survival, reduced lung consolidation, and reduced lung viral titres in influenza B compared with suboptimum doses of single agents, whereas one dosing regimen of oseltamivir and ribavirin showed no greater effects than ribavirin alone for mice injected with A/New Caledonia/20/99 H1N1 Triple-combination antiviral drug (TCAD) treatment Three available agents : amantadine+ ribavirin+ oseltamivir Influenza A viruses that are susceptible Resistant to the adamantanes or oseltamivir at baseline, including adamantane-resistant 2009 pandemic H1N1 virus. Favipiravir (法匹拉韦) 日本埃博拉药物 一种能有效对抗甲型和乙型流感以及其他RNA病毒的口服 RNA多聚酶抑制剂,该药与神经氨酸酶抑制剂或金刚烷胺类 药物无交叉耐药性。 Spectrum: Influenza A, B, and C viruses including adamantane-resistant or oseltamivirresistant variants Part2 Antibacterial drugs (抗菌药) -Lactam antibiotics Macrolides ( 大 环 内 酯 类 ), vancomycins (万古霉素) lincomycins ( 林 可 霉 素 类 ), Aminoglycosides (氨基糖苷类) & polymyxins(多黏菌素类) Tetracyclines(四环素类)& chloramphenicol(氯霉素) Synthetic antimicrobial agents(人工合成抗菌药) Quinolones Sulfonamides Antifungal agents Antituberculous drugs and Classification and mechanism of action ① ④ ⑤ ③ ② Contents 1、-Lactam Antibiotics(内酰胺类) 2、Macrolides (大环内酯类) 3、Quinolones(喹诺酮类) 4、Sulfonamides (磺胺类) 5、Tetracyclines(四环素类) 6、Aminoglycosides(氨基糖苷类) 7、Antituberculous drugs(抗结核药) 1、-Lactam Antibiotics 青霉素类 头孢菌素类 碳青霉烯类 β-Lactam Antibiotics 内酰胺酶抑制剂 单环类 I. Penicillins β-Lactam Antibiotics 1. Classification of Penicillins: (1)Nature penicillins: Penicillin G(苄青霉素, 简称青霉素) (2)Penicillinase-resistant penicillins: Oxacillin(苯唑西林) (3)Broad-spectrum penicillins: Amoxicillin(阿莫西林) (4)Anti-pseudomonas penicillins: Ticarcillin(替卡西林) (5)Anti-G- bacilli penicillins: Mecillinam(美西林) β-Lactam Antibiotics Mechanism of action: (1)Inhibiting transpeptidase(转肽酶, PBP, 青霉素结合蛋白), and inhibiting the synthesis of bacterial cell walls. (2)Activation of cell-wall autolytic enzyme(自溶酶). β-Lactam Antibiotics Semi-synthetic Penicillins: 1. Penicillins by oral administration (耐酸青霉素): Phenoxymethylpenicillin (苯氧甲基青霉素, Penicillin V) It is resistant to gastric acid, and be well absorbed(60%) when it is given on an empty stomach. Its half-life(t½) is longer than that of penicillin G. A satisfactory substitute for Penicillin G to treat tonsilitis(扁桃体炎), or Pharyngitis(咽炎), etc. Semisynthetic Penicillins 2. The penicillinase-resistant penicillins(耐酶青霉素): Oxacillin(苯唑西林), Cloxacillin(氯唑西林), Dicloxacillin(双氯西林) It is stable in an acidic medium, can be administrated by po, or im, iv ; and it is resistant to cleavage by penicillinase. It is used for treatment of penicillin Gresistance staphylococcal infection. Semisynthetic Penicillins 3. Broad spectrum penicillins(广 谱青霉素): Amipicillin(氨苄西林), Piperacillin(哌拉西林), etc. They have similar antibacterial activity and a broader spectrum. All can be destroyed by -lactamase. Semisynthetic Penicillins Broad spectrum penicillins (1)Ampicillin(氨苄西林), Amoxicillin(阿莫西林) Pseudomonas aeruginosa(铜绿假单孢菌 ——绿脓杆菌)-resistance. Clinical Uses: Upper respiratory infections; Urinary tract infections; Meningitis; Salmonella infections. Semisynthetic Penicillins Broad spectrum Penicillins (2)Piperacillin(哌拉西林),Mezlocillin(美洛西林) They have the broadest antibacterial spectrum, and the most activity of the penicillins, with activity against Pseudomonas aeruginosa, etc. Clinical Uses: For the treatment of the patients with severe infection caused by G- bacteria, usually in combination with aminoglycoside (氨 基苷类). 4.Anti-pseudomonas penicillins Carbenicillin(羧苄西林) Ticarcillin(替卡西林) With activity against Pseudomonas aeruginosa and some Proteus(变形杆菌). Semisynthetic Penicillins 5. Anti-G- bacilli penicillins: Mecillinam(美西林), Temocillin(替莫西林) They are bacteriostatic drugs, and have narrow antibacterial spectrum, with activity against some G- bacilli. 耐 酸 青 霉 耐酶青霉素 素 广 谱 青 霉 抗绿脓广谱 素 窄谱 G- 抗 菌 谱 似 抗菌谱似青霉 抗菌谱广 青霉素 素 广、抗绿脓 大肠埃希菌 耐酸 耐酸 耐酸 多不耐酸 不耐酸 不耐酶 耐酶 不耐酶 不耐酶 不耐酶 作用弱 作用弱 作用强 作用强 G-杆菌强 青 霉 素 V 、苯唑西林、甲 氨 苄 西 林 、羧苄西林、替卡西 美西林、替莫 苯 氧 乙 基 氧西林、双氯 羟 氨 苄 西 林、呋苄西林、阿 西林、匹美西 青霉素 西林、氯唑西 林 洛西林、美洛西林 林 林、氟氯西林 与哌拉西林 主 要 用 于 用于耐青霉素 用 于 呼 吸 G+ 球 菌 引 的葡萄球菌所 道 、 尿 道 起 的 轻 度 致的感染等 感染等 感染 主要用于变形杆菌 和铜绿假单胞菌引 起的感染哌拉西林 主要用于治疗G-引 起的严重感染 用于大肠杆菌 和某些敏感菌 引起的尿路感 染与软组织感 染 II. Cepharosporins Cepharosporins 1. First generation: Cefazolin( 头 孢 唑 林 ), Cefradine( 头 孢 拉 定 ), Cefalexin(头孢氨苄), etc. (1)more active than second and third generation against certain G+ microoganisms; (2)more impervious than second and third generation to attack by staphyloccal -lactamase; (3)less active than second and third genera-tion against certain G- microoganisms; (4)non-stable to G- bacilli -lactamase; (5)more activity against certain Pseudomonas (铜 绿假单孢菌), anaerobes(厌氧菌), etc; (6)certain kinds have kidney toxicity. Cepharosporins 2. Second generation: Cefuroxime(头孢呋辛), Cefamandole(头 孢孟多), Cefaclor(头孢克洛), etc. (1)more active than first generation against certain G- bacilli and more impervious than first generation G- bacilli -lactamase; (2)somewhat less active than first generation against G+ cocci but more than third generation; (3)active against anaerobes(厌氧菌); (4)lack activity against Pseudomonas; (5)less toxic than first generation to kidney. Cepharosporins 3. Third generation: Ceftazidime(头孢他啶), Ceftriaxone(头孢曲松 ), etc. (1)far more active than first and second generation against G- bacilli; (2)be highly resistant to -lactamase produced by G- bacilli; (3)with the extended spectrum against anaerobes and Pseudomonas; (4)well absorbed, penetration into tissue, blo-od and body cavity as well in sufficient concen-tration; (5)less active than first and second generation against G+ cocci; (6)less toxic to kidney. Cepharosporins 4. Fourth generation: Cefepime(头孢匹肟), Cefpirome(头孢匹 罗), etc. (1)resistant to type 1 -lactamase; (2)more active than third generation against Enterbacter(耐肠杆菌); (3)less active than third generation against Pseudomonas. Ⅲ. Other -lactam antibiotics 1. Cephamycins(头霉素类): Cefoxitin (头孢西丁) It has the similar antibacterial activity and spectrum to the second generation cepharosporins, also can be used for the treatment of anaerobic infections. Other -lactam antibiotics 2. Carbapenems(碳青霉烯类): Imipenem(亚胺培南) Imipenem is markered in combination with cilastatin(西司他丁)— —Tienam(泰能), a drug that inhibits the degradation of imipenem by a renal tubular dipeptidase. It has the broadest antibacterial spectrum and the most activity of all the antibiotic. Other -lactam antibiotics 3. Monobectams(单环类): Aztreonam(氨曲南) Carumonam(卡芦莫南) For the treatment of aerobic G+ bacilli infections. Narrow-spectrum antibiotic. Other -lactam antibiotics 4. Oxacephalosporins(氧头孢烯类) Latamoxef(拉氧头孢) Flomoxef(氟氧头孢) Broad-spectrum antibiotic(anaerobic infections). Ⅳ. -lactamase inhibitors (-内酰胺酶抑制剂) Clavulanic acid(克拉维酸) Sulbactam(舒巴坦) Tazobactam(三唑巴坦) Binding to -lactamases and inactivate them, thus preventing the destruction of -lactam antibiotics which are substrates for -lactamases. β-内酰胺类抗生素的复方制剂 复方制剂 抗菌药 辅助药 优立新 氨苄西林 舒巴坦 奥格门汀 阿莫西林 克拉维酸 他唑星 哌拉西林 他唑巴坦 舒普深 头孢哌酮 舒巴坦 Macrolides 2、Macrolides 1952 Erythromycin(红霉素) 1970s Acetylspiramycin(乙酰螺旋霉素) Medecamycin(麦迪霉素) josamycin(交沙霉素) 1980s Clarithromycin (克拉霉素) Roxithromycin(罗红霉素) Azithromycin(阿奇霉素) 2000s- Telithromycin(替利霉素) Mechanism of action Macrolides Macrolides (M) bind to the 50S subunit and block transpeptidation Antimicrobial spectrum Macrolides G+ organisms: -Cocci: streptococcus pyogenesand pneumoniae (化脓性 和肺炎链球菌) - Bacilli: Diphtheria白喉, Pertussis百日咳 Atypical pathogens: - Mycoplasma pneumoniae (肺炎支原体) - Legionella pneumophila (军团菌) - Chlamydia pneumoniae(衣原体). Pharmacokinetics Good oral bioavailability ( azithromycin absorption is impeded by food). Widely Distribution (Azithromycin is unique in that the levels achieved in tissues and in phagocytes are considerably higher than those in the plasma). Fairly rapidly elimination erythromycin (via biliary excretion) :half-lives of 2 clarithromycin (via hepatic metabolism and urinary excretion of intact drug) : half-lives 6 h. Azithromycin is eliminated slowly (half-life 2–4 days), mainly in the urine as unchanged drug. Macrolides Clinical uses As penicillin substitute in penicillin-allergic or resistant patients with infections caused by staphylococci(金葡菌), streptococci (链球菌) and pneumococci (肺炎球菌) Pertussis(百日咳),diphtheriae(白喉) Legionella ( 军 团 菌 )and mycoplasma pneumonia(肺炎支原体) H.p infection Macrolides Azithromycin (阿齐霉素) Strongest activity against mycoplasma pneumoniae(肺炎支原体) More active against Moraxella catarrhalis(卡他莫拉 菌),Haemophilus influenzae(流感嗜血杆菌), Neisseria(奈 瑟 菌 属) More effective on Gram-negative bacteria Well tolerated T1/2 :35~48h once daily Mainly used in respitory tract infection: a 4-day course of treatment has been effective in community-acquired pneumonia. Macrolides Clarithromycin(甲红霉素,克拉霉素) Has the strongest activity on Grampositive bacteria, legionella pneumophila, chlamydia pneumoniae(衣 原 体 ) , Mycobacterium avium complex and H.p Good pharmacokinetic property Low toxicity The drug is also used for prophylaxis against and treatment of M avium complex and as a component of drug regimens for ulcers caused by H pylori. Adverse effects Macrolides Gastrointestinal irritation (common) via stimulation of motolin receptors : nausea, vomiting, abdominal cramps, etc. Allergic reaction: skin rashes, and eosinophilia, Hepatitis: A hypersensitivity-based acute cholestatic hepatitis(胆汁淤积性肝炎)may occur with erythromycin estolate. Auditory impairment(听觉障碍) Cardiac arrhythmias Inhibitor of hepatic cytochrome P450: increase the plasma levels of many drugs, including anticoagulants, carbamazepine, cisapride, digoxin, and theophylline. The lactone ring structure of azithromycin is slightly different from that of other macrolides, and drug interactions are uncommon because azithromycin does not inhibit hepatic cytochrome P450. Macrolides Third generation -- Ketolides(酮基大环内酯类) Telithromycin (泰利霉素) It is active in vitro against Streptococcus pyogenes, S pneumoniae, S aureus, H influenzae, Moraxella catarrhalis, mycoplasmas, Legionella, Chlamydia, H pylori, N gonorrhoeae, B fragilis, T gondii, and nontuberculosis mycobacteria. The drug can be used in community-acquired pneumonia including infections caused by multidrug-resistant organisms. Many macrolide-resistant strains are susceptible to ketolides because the structural modification of these compounds renders them poor substrates for efflux pump-mediated resistance and they bind to ribosomes of some bacterial species with higher affinity than macrolides. A dverse effects : hepatic dysfunctio , prolongation of the QTc interval. The drug is an inhibitor of the CYP3A4 drug-metabolizing system 3、 Quinolones Quinolones Generation 1 st (1962-1969) Examples Nalidixic acid, 萘啶酸 2 nd (1969-1979) Pipemidic acid 吡哌酸 Cinoxacin 西诺沙星 3 rd (1980-1996) Norfloxacin 诺氟沙星 Levofloxacin 左氧氟沙星 Ciprofloxacin 环丙沙星 Ofloxacin 氧氟沙星 sparfloxacin 司帕沙星 fluoroquinolone gemifloxacin (吉米沙星) 4 th (1997-) Clinafloxacin 克林沙星 Moxifloxacin 莫西沙星 Quinolones Classification of fluoroquinolone 1st generation : Norfloxacin Spectrum: common pathogens that cause urinary tract infections. 2nd generation: Ciprofloxacin and ofloxacin Spectrum: gramnegative bacteria and the gonococcus, many grampositive cocci, mycobacteria, and atypical pathgen (Mycoplasma , Chlamydophila ). 3rd-generation:levofloxacin , gemifloxacin, and moxifloxacin Respiratory fluoroquinolone ”呼吸喹诺酮” Spectrum: slightly less active than ciprofloxacin and ofloxacin against gram-negative bacteria but have greater activity against gram-positive cocci, including S pneumoniae and some strains of enterococci and methicillin-resistant Staphylococcus aureus (MRSA). The broadest-spectrum fluoroquinolones introduced to date, with enhanced activity against anaerobes. Quinolones Antimicrobial activity & spectrum Quinolones (1) Bactericidal and have significant PAE. (2)Excellent activity against aerobic gram-negative bacteria, some agents have activity against Pesudomonas. (3) Several newer agents with improved activity against aerobic gram-positive bacteria. (4) They also are effective against Chlamydia spp.(衣 原体), Legionella pneumophila(军团菌) ,anaerobic bacteria, mycobacteria(分枝杆菌). (5) Some agents have limited activity against multipleresistance strains. (6)Bactericidal concentration≥ bacteriostatic concentration Quinolones Quinolones Mechanism of actions The quinolone antibiotics target bacterial • Topoisomerase II-DNA gyrase (gram-negative bacteria) : • block the relaxation of supercoiledDNA • Topoisomerase IV (gram- positive bacteria). • interferes with the separation of replicated chromosomal DNA during cell division. Pharmacokinetics Good oral bioavailability (antacids containing multivalent cations may interfere) Good penetration to most body tissues. norfloxacin does not achieve adequate plasma levels for use in most systemic infections. Elimination via active tubular secretion (excepte for moxifloxacin): which can be blocked by probenecid(丙磺舒). Dosage reductions are usually needed in renal dysfunction except for moxifloxacin which is eliminated partly by hepatic metabolism and also by biliary excretion. so Use of moxifloxacin in urinary tract infections is not recommended. Half-lives : 3–8 h. Clinical Uses Quinolones Levofloxacin has activity against most organisms associated with community-acquired pneumonia, including chlamydiae, mycoplasma, and legionella species. Gemifloxacin and moxifloxacin have the widest spectrum of activity, which includes b o t h gr a m - p osi t i v e a n d g r a m - ne g at i v e organisms, atypical pneumonia agents, and some anaerobic bacteria. Toxicity Quinolones Gastrointestinal distress is the most common adverse effect. others: skin rashes, headache, dizziness, insomnia, abnormal liver function tests, phototoxicity(光毒性), and both tendinitis (腱炎)and tendon rupture(腱断裂). The fluoroquinolones are not recommended for children or pregnant women because they may damage growing cartilage and cause arthropathy. Fluoroquinolones may increase the plasma levels of theophylline and other methylxanthines, enhancing their toxicity. Newer fluoroquinolones (gemifloxacin, levofloxacin, moxifloxacin) prolong the QTc interval.They should be avoided in patients with known QTc prolongation and those on certain antiarrhythmic drugs or other drugs that increase the QTc interval. 4. Sulfonamides short-acting : sulfisoxazole intermediate-acting: sulfamethoxazole long-acting: sulfadoxine. Bacteriostatic inhibitors of folic acid synthesis. competitive inhibitors of dihydropteroate synthase Trimethoprim—a selective inhibitor of bacterial dihydrofolate reductase Inhibitory effects of sulfonamides and trimethoprim on folic acid synthesis. Pharmacokinetic features Modest tissue penetration Bind to plasma proteins at sites shared by bilirubin(胆 红素) and by other drugs. Hepatic metabolism Excretion: both intact drug and acetylated metabolites in the urine. Solubility may be decreased in acidic urine, resulting in precipitation of the drug or its metabolites. Solubility limitation: a combination of 3 separate sulfonamides (triple sulfa) has been used to reduce the likelihood that any one drug will precipitate. Clinical Use Trimethoprim-sulfamethoxazole (TMP-SMZ) Effective orally in the treatment of urinary tract infections and in respiratory, ear, and sinus infections caused by Haemophilus influenzae(流感嗜血杆菌) and Moraxella catarrhalis(卡他莫拉菌). In the immunocompromised patient, TMP-SMZ is used for infections due to Aeromonas hydrophila (嗜水气单胞菌)and is the drug of choice for prevention and treatment of pneumocystis pneumonia(肺孢子菌肺炎). An intravenous formulation is available for patients unable to take the drug by mouth and is used for treatment of severe pneumocystis pneumonia and for gram-negative sepsis. TMP-SMZ is also the drug of choice in nocardiosis(诺卡氏菌病), a possible backup drug for cholera(霍乱), typhoid fever(伤寒), and shigellosis(志贺氏菌), and has been used in the treatment of infections caused by methicillin-resistant staphylococci and Listeria monocytogenes. 5. Tetracyclines Clinical used tetracyclines: Tetracycline(四环素); Demeclocycline(地美环素, 去甲金霉素); Metacycline(美他环素, 甲烯土霉素); Doxycycline(多西环素, 强力霉素); Minocycline(米诺环素, 美满霉素). (Antimicrobial activity enhanced from up to down) Tigecycline (替加环素) --甘氨酰四环素类中的首个药品 新型的广谱活性的静脉注射用抗生素 Tetracyclines Antimicrobial spectrum Broad-spectrum antibiotic (1) Active against a wide range of aerobic and anaerobic gram-positive and gram-negative bacteria. (2) Effective against Rickettsia( 立 克 次 体 ) ,Coxiella burnetii ( 螺 旋 体 ) ,Mycoplasma pneumoniae ( 支 原 体),Chlamydia (衣原体), and Plasmodium (疟原虫). (3) They are not active against fungi,virus. Tetracyclines Pharmacokinetics Oral absorption is variable, especially for the older drugs, and may be impaired by foods and multivalent cations (calcium, iron, aluminum). Wide tissue distribution and cross the placental barrier. Undergo enterohepatic cycling. Doxycycline is excreted mainly in feces; the other drugs are eliminated primarily in the urine. The half-lives of doxycycline and minocycline are longer than those of other tetracyclines. Tigecycline, formulated only for IV use, is eliminated in the bile and has a half-life of 30–36 h. Mechanism of action Tetracyclines Mechanism of action: ①Chloramphenicol ②Macrolides, Clindamycin ③Tetracyclines •Inhibits binding of 30S subunit with A site •Interfering with the binding of aminoacyl-tRNA with aminoacyl site(A site) Clinical Uses Tetracyclines Primary uses—Tetracyclines are recommended in the treatment of infections caused by Mycoplasma pneumoniae (in adults). Doxycycline is currently an alternative to macrolides in the initial treatment of community-acquired pneumonia. Secondary uses—Tetracyclines are also used in the treatment of respiratory infections caused by susceptible organisms, for prophylaxis against infection in chronic bronchitis. Toxicity Gastrointestinal disturbances Bony structures and teeth Hepatic toxicity Tetracyclines Renal toxicity: One form of renal tubular acidosis, Fanconi’s syndrome Photosensitivity Vestibular toxicity(前庭毒性) 6. Aminoglycosides(氨基糖苷类) • Natural Aminoglycosides • 链霉素(streptomycin) • 新霉素(neomycin) • 妥布霉素(tobramycin) • 卡那霉素(kanamycin) • 大观霉素(spectinomycin) • Semisynthetic Aminoglycosides (amikacin) 阿米卡星 • 庆大霉素(gentamicin) 西索米星(sisomicin) 小诺米星(micronomicin) 奈替米星(netilmicin) Mechanism of action Pharmacokinetics Poorly absorbed from the gastrointestinal tract. Systemic infection: must be given intramuscularly or intravemously for excreted almost entirely unchanged by glomerular filtration, which is greatly reduced in renal impairment, causing toxic blood levels. Adverse effects Ototoxicity Nephrotoxicity Neuromuscular blockade Skin Reactions Supplyment Linezolid Oxazolidinones(恶唑烷酮类)--- Linezolid (利奈唑 胺) Linezolid is a member of the oxazolidinones, a new class of synthetic antimicrobials. Mechanism of action Mechanism of Resistance Linezolid inhibits protein synthesis by preventing formation of the ribosome complex that initiates protein synthesis. Its unique binding site, located on 23S ribosomal RNA of the 50S subunit, results in no cross-resistance with other drug classes. Resistance is caused by mutation of the linezolid binding site on 23S ribosomal RNA. Linezolid Antimicrobial spectrum: It is active against gram-positive organisms including staphylococci, streptococci, enterococci, gram-positive anaerobic cocci, and gram-positive rods such as corynebacteria and Listeria monocytogenes. It is primarily a bacteriostatic agent except for streptococci for which it is bactericidal. There is modest in vitro activity against Mycobacterium tuberculosis. Adverse reaction Pharmacokinetics Clinical uses Linezolid The principal toxicity of linezolid is hematologic—reversible and generally mild. Thrombocytopenia(血小板减少症) is the most common manifestation (seen in approximately 3% of treatment courses), particularly when the drug is administered for longer than 2 weeks. Neutropenia may also occur, most commonly in patients with a predisposition to or underlying bone marrow suppression. Linezolid is 100% bioavailable after oral administration and has a halflife of 4–6 hours. It is metabolized by oxidative metabolism, yielding two inactive metabolites. It is neither an inducer nor an inhibitor of cytochrome P450 enzymes. Peak serum concentrations average 18 g/mL following a 600 mg oral dose. The recommended dose for most indications is 600 mg twice daily, either orally or intraveneously. Vancomycin-resistant E faecium infections; nosocomial pneumonia(医院获得性肺炎); community-acquired pneumonia(社区获得性肺炎); skin infections Antituberculous Drugs 7. Main Antituberculous Drugs: First-line agents: Isoniazid(异烟肼), 1945 Rifampin(利福平), 1965 Ethambutol(乙胺丁醇), 1959 Streptomycin(链霉素), 1944 Pyrazinamide(吡嗪酰胺), 1952 Second-line agents: Para-aminosalicylic(对氨水杨酸), Ethionamide(乙硫异烟胺) Amikacin(阿米卡星) Capreomycin(卷曲霉素) Fluoroquinolones: Ciprofloxacin( 环 丙 沙 星 ), Ofloxacin(氧氟沙星), etc. Antitubercular Drug Regimens Standard regimens—3-drug regimen INH+rifampin+pyrazinamide If the organisms are fully susceptible (and the patient is HIVnegative), pyrazinamide can be discontinued after 2 mo and treatment continued for a further 4 mo with a 2-drug regimen. Alternative regimens— INH + rifampin for 9 mo or INH + ETB for 18 mo. Intermittent (2 or 3 × weekly) high-dose 4-drug regimens are also effective. Resistance—If resistance to INH is higher than 4%, the initial drug regimen should include ethambutol or streptomycin. resistant only to INH : RIF + pyrazinamide + ethambutol or streptomycin. 6 mo Multidrug-resistant organisms (resistant to both INH and rifampin) : 3 or more drugs to which the organism is susceptible for a period of more than 18 mo, including 12 mo after sputum cultures become negative. One of several recommended multidrug schedules for the treatment of tuberculosis. Part3 Antifungal drugs (抗真菌药) 1、Antibiotic (抗生素类): Amphotericin B(两性霉素B ); Nystatin(制霉菌素) Griseofulvin(灰黄霉素) 2、Azole (唑类) : Imidazoles (咪唑类):ketoconazole(酮康唑), Triazoles(三唑类): Itraconazole(伊曲康唑), 3、Allylamine(丙烯胺类): Terbinafine (特比萘芬) 4、Pyrimidine (嘧啶类) : Flucytosine (氟胞嘧啶) 5、Echinocandins(棘白菌素类) Caspofungin(卡泊芬净) Mechanism of action 4.嘧啶类 3.丙烯胺类 1.抗生素类 2.唑类 5.棘白菌素类 END OF CLASS