Summary Pharmacology Module 2 Notes: Week 3, 4, & 5

Pharmacology Module 2 Notes: Week 3,
4, & 5
Week 3

Basic Principles Of Antimicrobial Therapy Chapter 83

- Antimicrobials

• Used To Treat Infectious Diseases

• Up To 30% Of All Hospitalized Patients Receive Antimicrobials

• Modern Antimicrobials - 1930s And 1940s

• Significantly Reduced Morbidity And Mortality From Infection

- Basic Principles Of Antimicrobial Therapy

• Chemotherapy

- Use Of Chemicals Against Invading Organisms

• Antibiotic

- Strictly Speaking - A Chemical That Is Produced By One Microbe And Has The Ability To Harm
Other Microbes

• Antimicrobial Agent

- Any Agent That Has The Ability To Kill Or Suppress Microorganisms

- Selective Toxicity

• Toxic To Microbes - Harmless To Host

• Disruption Of Bacterial Cell Wall

• Inhibition Of An Enzyme Unique To Bacteria

• Disruption Of Bacterial Protein Synthesis

- Classification Of Antimicrobial Drugs

• Various Themes Used To Classify



• The Two Used For This Textbook:

,- Classification By Susceptible Organs,

- Classification By Mechanism Of Action

• 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

- Acquired Resistance To Antimicrobial Drugs

• Over Time, Organism Develop Resistance

• May Have Been Highly Responsive And Then Became Less Susceptible To One Or More Drugs

- Organisms With Microbial Drug Resistance

• Enterococcus Faecium, Staphylococcus Aureus, Enterobacter Species, Klebsiella Species,
Pseudomonas Aeruginosa, Acinetobacter Baumannii, Clostridium Difficile

- Microbial Mechanisms Of Drug Resistance

• Four Basic Actions

- Decrease The Concentration Of A Drug At Its Site Of Action

- Inactivate A Drug

- Alter The Structure Of Drug Target Molecules

- Produce A Drug Antagonist

- Mechanisms Of Acquired Resistance

• Spontaneous Mutation



• Conjugation

- Antibiotic Use And Drug Resistant Microbe Emergence

• How Antibiotic Use Promotes Resistance

• Which Antibiotics Promote Resistance

,• The Amount Of Antibiotic Impacts Resistance

• Nosocomial Infections

• Suprainfection (Superinfection)

- Delaying Emergence Of Drug Resistance

• Vaccinate

• Get The Catheters Out

• Target The Pathogen

• Access The Experts

• Practice Antimicrobial Control

• Use Local Data

• 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

- Selection Of Antibiotics

• Identify Organism

• Drug Sensitivity Of Organism

• Host Factors

• Drug May Be Ruled Out Owing To

- Allergy



- Inability To Penetrate The Site Of Infection

- Patient Variables

- Empiric Therapy

• Antibiotic Therapy For Patients Before Causative Organism Is Positively Identified

• Drug Selection Based On

- Clinical Evaluation

, - Knowledge Of Microbes Most Likely To Have Caused Infection

- Identifying The Infection Organism

• Match The Drug With The Bug

• Gram-Stained Preparation

• Determining Drug Susceptibility

- Disk Diffusion Test

- Broth Dilution Procedure

- Host Factors

• Host Defenses

• Site Of Infection

• Age

• Pregnancy And Lactation

• Previous Allergic Reactions

• Genetic Factors

- Dosage Size And Duration

• Antibiotic Must Be Present

- At The Site Of Infection

- For A Sufficient Length Of Time

• Antibiotics Must Not Be Discontinued Prematurely

• Teach Patients To Complete Full Prescription



- Antibiotic Combinations

• Antimicrobial Effects Of Antibiotic Combinations

- Additive, Potentiative, Antagonistic

• Indications

- Mixed Infections, Prevention Of Resistance, Decreased Toxicity, And Enhanced Bacterial Action

• Disadvantages Of Combinations

- Prophylactic Use Of Antimicrobials

• Agents Given To Prevent Infection Rather Than To Treat An Established Infection