抗微生物药物（英文PPT）.ppt

Chapter 21:AntimicrobialMedications Important Point: Antimicrobial Chemotherapeutics Antibiotic Discovery Antimicrobal Chemotherapy Terms Distinguishing Antibiotics Distinguishing Antibiotics Antibiotics Sources Distinguishing Antibiotics Family Tree of Penicillins Some Penicillin Derivatives Methicillin-Induced Lysis Vancomycin Cell-Wall Synthesis Inhibitors Distinguishing Antibiotics Therapeutic Index Therapeutic Index Therapeutic Index Distinguishing Antibiotics Distinguishing Antibiotics Spectrum of Activity Spectrum of Activity Distinguishing Antibiotics Fluctuation of Antibiotic Levels with Time Distinguishing Antibiotics Finding Targets Targets of Antibacterial Drugs Targets of Antibacterial Drugs Ribosomal Targets Tetracyclines Tetracycline Distinguishing Antibiotics Combination of Drugs Combination of Drugs Mutation to Resistance Rational for Combining Drugs Consequence of Not Combining Consequence of Not Combining Not Maintaining Course Distinguishing Antibiotics Acquired Antibiotic Resistance Acquired Antibiotic Resistance Resistance in Simpler Terms… Chromosomal vs. R Plasmid Encoded Distinguishing Antibiotics Distinguishing Antibiotics Link to Next Presentation Antibiotics (as well as synthetic antimicrobials) differ in terms of… The organism they are or were isolated from. Their chemical structure. Their (chemo)Therapeutic index. Bacteriostasis versus bacteriostatic. Their spectrum of activity. Their pharmacokinetics (tissue distribution, metabolism, and excretion). Their site of action in bacterial cells. Interaction with other chemotherapeutics. Potential for evolution to resistance. Mechanism of toxicity to the host. Cost. For antibiotics “A” and “B” used in combination: Actual killing rate = A + B ? Additive Actual killing rate A + B ? Synergistic Actual killing rate A + B ? Antagonistic Typically bacteriostatic agents are antagonistic to bactericidal agents. Bacteriocidal agents can be synergistic (think of the latter as one antibiotic weaken