Copyright (c) 2004 Elsevier Inc. All rights reserved. Basic Principles of Antimicrobial Therapy Chapter 79

Copyright (c) 2004 Elsevier Inc. All rights reserved. Basic Principles of Antimicrobial Therapy Define –Chemotherapy –Antibiotic –Antimicrobial agent –Selective toxicity –Narrow spectrum antibiotic –Broad spectrum antibiotic

Copyright (c) 2004 Elsevier Inc. All rights reserved. Classification of Antibiotics Drugs work on –Cell wall synthesis –Cell membrane permeability –Protein synthesis (lethal) – Nonlethal inhibitors of protein synthesis –Synthesis of nucleic acids –Antimetabolites –Viral enzyme inhibitors

Copyright (c) 2004 Elsevier Inc. All rights reserved. Mechanisms of Microbial Drug Resistance Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Klebsiella pneumoniae Spontaneous mutation Conjugation

Copyright (c) 2004 Elsevier Inc. All rights reserved. Delaying Emergence of Drug Resistance Vaccinate Get the catheters out Target the pathogen Access the experts Practice antimicrobial control Use local data

Copyright (c) 2004 Elsevier Inc. All rights reserved. Delaying Emergence of Drug Resistance (cont.) Treat infection, not contamination Treat infection, not colonization Know when to say “no to vanco” Stop treatment when infection is cured or unlikely Isolate the pathogen Break the chain of contagion

Copyright (c) 2004 Elsevier Inc. All rights reserved. Selection of Antibiotics Identify organism Drug sensitivity of organism Host factors Allergy Penetration to site of infection Patient variables

Copyright (c) 2004 Elsevier Inc. All rights reserved. Misuses of Antimicrobial Drugs Untreatable infection Fever of unknown origin Improper dosage Lack identification of organism Omission of surgical drainage