Advanced Practice Education Associates Antibiotics
Overview Difference between Gram Positive(+), Gram Negative(-) organisms Beta lactam ring, allergies Antimicrobial Spectra of Antibiotic Classes 78 Copyright 2016 Advanced Practice Education Associates
GRAM POSITIVE (+) AND GRAM NEGATIVE (-) Gram Positive (+) Bugs Staph Strept Enterococcus Listeria, Propionibacterium, Corynebacterium (diphtheria), Clostridium (tetanus, botulism), Bacillus anthracis Gram Negative (-) Bugs Just about everything else! Staphylococcus Gram Positive (+) Bugs Staphylococcus aureus (skin) MRSA (Staphylococcus aureus)(skin) Staph saprophyticus (UTI, vagina) Staph epidermis (skin) Gram Positive (+) Bugs Strept pyogenes (throat) Strept pneumoniae (lungs) Strept viridans (dental abscess, endocarditis) Strept agalactiae (Group B Strept) Enterococcus Gram Positive (+) Bugs Enterococcus faecalis (Urinary tract) Enterococcus faecium (Urinary tract) Other Gram Positive (+) Bugs Listeria monocytogenes (listeriosis) Corynebacterium diphtheriae (diphtheria) Clostridium botulinum (botulism), Clostridium tetani (tetanus), Clostridium difficile Bacillus anthracis (anthrax) Propionibacterium acne (acne) Additional Notes:
Gram Negative (-) Bugs Just about everything else! Neisseria gonorrhoeae Neisseria meningitidis E. coli, Shigella, Campylobacter, Salmonella Pasturella Rickettsia, Borrelia Proteus, Pseudomonas, Legionella, others Gram Negative (-) Bugs Atypical Pathogens: Mycoplasma, H. flu, M. cat Legionella, others Empiric Treatment 2 Concepts Difference between Gram positive and Gram Negative Bugs Beta Lactam Ring BETA-LACTAM RING, ALLERGIES What s a Beta-Lactam? It s an antibiotic with a beta-lactam ring Any PCN or cephalosporin Beta Lactam Ring 2 Points Allergic reactions Beta lactamase Question: If you are allergic to the pink pentagon, can you safely take a cephalosporin? If you are allergic to the blue box, can you safely take a cephalosporin? 80 Copyright 2016 Advanced Practice Education Associates
"I am allergic to PCN" Estimated 90-98% of PCN allergic patients are allergic to the pink pentagon and can safely take cephalosporins! AT MOST: 2-10% of patients who are allergic to PCN are allergic to the blue box AND will also be allergic to cephalosporins Amelie's Rules Rule 1: Never give a cephalosporin if PCN reaction was anaphylaxis!!! Rule 2: Don t give a cephalosporin if PCN reaction was HIVES!!! Rule 3: Give a cephalosporin if PCN reaction was morbilliform rash!!! Morbilliform Rash Rash is macular or maculopapular, lesions are fixed, area expands over several days May itch More prevalent in children More common with aminopenicillins (amox and ampicillin) Usually T-cell mediated Concurrent viral infections predispose patients to morbilliform rash Unknown mechanism by which this occurs Beta Lactam Ring Second Point Allergies Beta lactamase What is Beta-Lactamase? An enzyme that smart bacteria learn how to produce What does Beta-Lactamase do? It destroys the beta-lactam ring of the antibiotic! Smart Chemists We will not be outsmarted by the bugs!
Quiz: Gram Positive or Gram Negative MRSA MSSA DRSP THE ANTIBIOTICS Penicillins PENICILLINS Ampicillin, Amoxicillin Penicillin G, Penicillin K Gram Positives NOT Staphylococcus Group A,B,C,G Enterococcus Strept pneumoniae Drug Resistant Strept pneuma (DRSP) Botulism (wound, not food) Quiz Can amoxicillin really kill DRSP? What dose for Adults? What dose for Peds? Extended Spectrum PENICILLINS Amoxicillin/Clavulanic acid (Augmentin) Gram Positives, Gram Negatives β-lactamase, NOT MRSA Strept Group A,B,C,G Enterococcus Strept pneumoniae DRSP MSSA H. influenza, M. catarrhalis, E. coli, Neisseria, Corynebacterium diphtheria Quiz How would you know if a bug produced beta-lactamase? Additional Notes: 82 Copyright 2016 Advanced Practice Education Associates
Sulfonamides TMP-SMX (Bactrim, Septra) Gram Negatives MRSA, MRSA, CA-MRSA Not STREPT Not E. coli Tetracyclines Doxycycline, Minocycline Vibramycin Gram Negatives Atypicals, MRSA Minocycline is good choice for MSSA and CA-MRSA Doxy/Mino good choices for atypical pathogens and lower resp tract pathogens H. flu, E. coli, Legionella, Mycoplasma, Chlamydophila, Rickettsia Cephalosporins 1 st Generation Cephalexin (Keflex) Cefadroxil (Duricef) Gram Positives Strept 2 nd Generation Cefuroxime (Ceftin) Cefaclor (Ceclor) Cefprozil (Cefzil) Gram Positives, Gram Negatives H. flu E. coli Proteus mirabilis
3 rd Generation Ceftibuten (Cedax), Cefixime (Suprax) Weak Gram Positives, Gram Negatives β-lactamase Producers Strept Groups NOT Staph H. flu, M. cat, E. coli, Klebsiella, Salmonella, Shigella Extended Spectrum 3 rd Generation Ceftriaxone (Rocephin), Cefdinir (Omnicef), Cefpodoxime (Vantin), Cefditoren (Spectracef) Gram Positives, Gram Negatives β-lactamase Producers Strept H. flu, M. cat, E. coli, Salmonella, Shigella, Proteus mirabilis Macrolides Early Generation Erythromycin Atypical pathogens NOT Staph NOT Strept NOT Enterococcus Listeria M. cat Legionella Chlamydophila Mycoplasma Macrolides Later Generation Azithromycin (Zithromax) Clarithromycin (Biaxin) Atypical Pathogens NOT Strept NOT Enterococcus Listeria M. cat Legionella Chlamydophila Mycoplasma Additional Notes: 84 Copyright 2016 Advanced Practice Education Associates
Fluoroquinolones 2 nd Generation Ciprofloxacin (Cipro) Gram Negatives Atypical Pathogens NOT Strept NOT Enterococcus M. cat, H. flu, E. coli, Legionella, Chlamydophila, Mycoplasma, Klebsiella Other Gram negatives Respiratory Fluoroquinolones 3 rd Generation Levofloxacin (Levaquin) Gram Positives, Gram Negatives, Atypical Pathogens, DRSP, aerobes, anaerobes Listeria Strept: all, M. cat, H. flu, E. coli, Legionella, Chlamydophila, Mycoplasma, Klebsiella, ± Pseudomonas Respiratory Fluoroquinolones 4 th Generation Moxifloxacin* (Avelox) Gemifloxacin (Factive) Gatifloxacin (Zymar ophth) Gram Positives, Gram Negatives (above the belt) Atypical Pathogens, DRSP *GI pathogen coverage Listeria Not urinary pathogens Strept: all sp., M. cat, H. flu, E. coli, Legionella, Chlamydophila, Mycoplasma, Klebsiella Miscellaneous Nitrofurantoin (Macrobid) Urinary pathogens MSSA CA-MRSA (usually) E. coli Why don t we use nitrofurantoin for skin MRSA? Hint: Where does nitrofurantoin concentrate?
Miscellaneous Metronidazole (Flagyl) Gram negative Clostridium difficile Clostridium sp. Miscellaneous (Lincosamide) Clindamycin Gram positive MSSA CA-MRSA (usually) Miscellaneous Linezolid (Zyvox) Gram positive MSSA MRSA CA-MRSA Enterococcus Listeria Glycopeptide Vancomycin Gram positive MSSA CA-MRSA (usually) C. difficile (oral) Additional Notes: 86 Copyright 2016 Advanced Practice Education Associates