為什麼要用抗生素: 談細菌與抗藥性 李健明 MD, PhD
古代傳說 Greeks and Indians: moulds, plants; treat infections. Greece and Serbia: mouldy bread; wounds, infections Russia: warm soil; infected wounds Sumerian: soup w/ turtle shells, snake skin. Babylonian: frog bile, sore milk; eyes Sri Lankan: oil cake (sweetmeat); antibacterial
Paul Ehrlich and Sahachiro Hata 1903: Arsphenamine, Salvarsan, compound 606; 治療梅毒syphilis
Gerhard Domagk: Sulfa drug 1930s:USA, 100,000 people died annually from 肺炎(pneumonia) I.G. Farbenindustrie : Prontosil Streptococci: rats, rabbits 1933: a 10-month-old boy who was dying of 金黃葡萄球菌菌血症 (staphylococcal septicemia); his own daughter 1935: Farben; patent 1939: awarded the Nobel Prize
抗生素就是抗生物的素 Antibiotic = anti (against) + bio (life) 廣義:能抑制或殺死細菌的化合物 狹義:能抑制或殺死細菌的黴菌產生物和衍生物
盤尼西林的作用(Action of penicillins)
醫師、細菌、部位、濃度和時間 傷腎 細胞壁合成 細胞膜構造 蛋白質合成 RNA聚合酶 DNA促旋酶 最常見副作用: 過敏 葉酸的代謝 9大類: ~200種,50/hospital
蜂窩組織炎 vs 壞死筋膜炎 Staph, Strep (GAS) 1. Strep (GAS), Staph. 2. Vibrio vulnificus 3. Aeromonas hydrophila 4. Klebsiella pneumoniae 5. Gas gangrene: Clostridium perfringens
梅毒: 會傳給胎兒 用藥:盤尼西林, 四環黴素,紅黴素
細菌抗藥性如何產生 (基因突變)
Killing curve of Streptococcus pneumoniae by ceftriaxone Sensitive (MIC: 0.25- 0.5 µg/ml) Intermediate (MIC: 0.75-1 µg/ml) Resistance (MIC: 2-12 µg/ml)
抗藥性(某細菌、某抗生素、體內濃度達不到): selective pressure 用太多: 只殺細菌不殺病毒 農漁業 用太少 濃度不足: 劑量不足、腸子吸收力、肝功能 組織力:腦、攝護腺、骨髓 用太重: 劑量太多反效果 只有廣效 VS 窄效,無強弱之分 必然性: 細菌突變在先然後抗生素篩選