Pharmacology Unit 2: Applied Surgical Pharmacology Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc.

Unit 2  Focus is on:  Specific drugs  Purposes  General information  Make drug cards to learn information

Chapter 5 Antibiotics

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Note  This chapter covers only antibiotics.  Also known as antibacterials  There are also antivirals, antifungals, etc.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Antibiotics are  Natural chemicals produced by microbes  Possibly occurring in nature to give a microbe an advantage over other microbes?

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Antibiotics are  Natural microbial chemicals altered in the pharmaceutical laboratory  Source: semi-synthetic

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Note  Antibiotics only assist the immune system to fight an infection.  Bacteriostatic  Bactericidal

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Review C&S  Culture and sensitivity  Grow bacteria in colony  Identify organism  Determine which antibiotic works most effectively  Rapid Antibiotic Susceptibility Test (RAST)

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Review Gram’s stain  Series of stains showing type of cell wall  Gram negative  Red  Gram positive  Purple

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Gram’s identification  Staining properties  Negative, positive  Plus morphology  Round, oblong, spiral  Allow general identification of microbe  Determine course of therapy

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. To be effective  Agent must work against microbes without harming host  Called: selective toxicity

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 1 Define terminology related to antimicrobial therapy.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 1. Define terms  Antibiotic resistance  Ability of some strains of pathogenic microorganisms to prevent or overcome the activity of antibiotic agents  Bactericidal  Bacteria-killing: destructive to bacteria  Bacteriostatic  Bacteria-stopping: inhibiting the growth of bacteria

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 1. Define terms  Culture and sensitivity (C&S)  Series of tests used to identify pathogenic microorganisms and determine their susceptibility to various antibiotics  Endogenous  Source from within the patient  Eukaryotes  Multicelled organisms  Exogenous  Source from outside the patient

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 1. Define terms  Gram’s staining  A process used to identify major groups of bacteria by staining characteristics  Morphology  Study of shapes (to identify bacteria)  MRSA  Methicillin-resistant staphylococcus aureus  Nephrotoxicity  Toxic or harmful to the kidney  Ototoxicity  Toxic or harmful to the ear

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 1. Define terms  Polymicrobic infections  Caused by more than one microorganism  Prokaryotes  Single-celled organisms  Prophylaxis  Prevention

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 1. Define terms  Selective toxicity  A characteristic of antibiotics in which the agent is toxic to the infecting microorganism without harming the host  VRE  Vancomycin-resistant enterococci

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 2 Discuss the purpose of antibiotic therapy in surgery.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 2. Discuss purpose  Prophylaxis  Prevention of infection  Given Preoperatively Preoperatively Intraoperatively Intraoperatively Postoperatively Postoperatively  IV and topical

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 2. Discuss purpose  Treatment  Wound infections  Given Preoperatively Preoperatively Intraoperatively Intraoperatively Postoperatively Postoperatively  IV, topical, oral

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 3 Describe various ways in which antibiotics work.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 3  Review basic concepts of microbiology  Bacteria cause surgical site infections (SSI)  Treat without harming host  Determine differences between host and bacterial cells to find site for drug action

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Review basic microbiology  Prokaryotic cells  Single celled organisms  No true nucleus  Bacteria are prokaryotic

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Review basic microbiology  Eukaryotic cells  Multicelled organisms  Have a true nucleus  Humans are eukaryotic

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Prokaryotic  Two main structural differences:  Bacteria have  Cell walls  Smaller size ribosomes  Many antibiotics target cell wall or ribosome

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Antibiotic may  Kill or suppress microbe  Have a broad or narrow spectrum of activity  But still acts in one of 5 major ways

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 3  Inhibit cell wall synthesis  Prevent formation  Make it weak

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 3  Interfere with protein synthesis  Bind to ribosomes  Prevent protein assembly  Stops all vital cell functions

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 3  Alter cell membrane function  Disrupt it, make it “leaky”  Inhibit DNA/RNA synthesis  Prevent replication

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 3  Interfere with cell metabolism  e.g., substitute for something needed like chemical cell needs to make folic acid

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 4 Discuss antibiotic resistance.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 4  Define the term  Ability of some strains of pathogenic microbes to prevent or overcome the activity of antimicrobial agents.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Presents a major problem  Few truly new antibiotics in the last 15 years  Second, third, fourth generation of same antibiotic  Microbes have mutated faster than antibiotics have developed

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 4. Resistance  Resistance mechanisms  Microbe makes enzymes  Prevent agent from working e.g., penicillinase e.g., penicillinase

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 4. Resistance  Resistance mechanisms  Prevent agent from contact  Alter target area

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 4. Resistance is shared  Inheritance (mother to daughter)  Mutation  Random  Transformation — transfer  Transduction — phage  Conjugation

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. How do we contribute to antibiotic resistance?  Taking antibiotics for viral infections  Not taking complete dose

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 5 List categories of antibiotics used in surgery and examples of each.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 5  Aminoglycosides  Amikacin  Gentamicin  Streptomycin  Neomycin, kanamycin

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 5  Cephalosporins  1st generation Ancef, Keflex, Keflin Ancef, Keflex, Keflin  2nd generation Mefoxin, Ceclor, Zinacef Mefoxin, Ceclor, Zinacef

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 5  Cephalosporins  3rd generation Suprax, Rocephin Suprax, Rocephin  4th generation Maxipime Maxipime

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 5  Macrolides  Erythromycin, azithromycin  Penicillins  Methicillin, ampicillin, amoxicillin

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 5  Tetracylines  Vibromycin  Aureomycin

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 6 Identify the category of various antibiotics.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 6  The best way to learn this item is to make flash cards for antibiotics.  Generic and trade name on one side  Category on the other side

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 7 Use resources to gather pertinent information on antibiotics.

Elsevier items and derived items © 2006 by Saunders, an imprint of Elsevier Inc. Objective 7  Various types of resources  Most common at the hospital PDR PDR  Practice using PDR to look up familiar drugs  Then look up new drugs