Antibacterial Drugs Bacteria = prokaryotes 1. Cell Wall Synthesis Inhibitors A. Penicillins: bactericidal, prevent cross-linking of peptidoglycan, cause cell lysis Natural: Gram positives & spirochetes MRSA = Methicillin Resistant Staphylococcus aureus Synthetic: More broad spectrum Carbapenems Effective on 98% of hospital isolates Monobactams Some Gram negatives B. Cephalosporins: bactericidal, prevent cross-linking of peptidoglycan, cause cell lysis, broad spectrum C. Polypeptide Antibiotics 1. Bacitracin: bactericidal, inhibits linear strand synthesis, Gram positives Topical only 2. Vancomycin: bactericidal, prevent cross-linking, cause cell lysis, Gram positives VRE = Vancomycin Resistant Enterococci D. Antimycobacterial Antibiotics: bacteriostatic, inhibit synthesis of mycolic acid 1. Isoniazid 2. Ethambutol 2. Protein Synthesis Inhibitors A. Chloramphenicol: bacteriostatic, inhibits peptide bond formation, broad spectrum Diffuses easily into tissues, cheap Toxicity: -neurotoxic, -reduced bone marrow function → anemia & leukopenia B. Aminoglycosides: bactericidal, inhibit synthesis and cause misreading of mRNA, Gram negatives Toxicity: -auditory nerve damage -kidney damage Amy Warenda Czura, Ph.D.1SCCC BIO244 Chapter 20 HandoutC. Tetracyclines: bacteriostatic, inhibit binding of tRNA, broad spectrum including intracellular pathogens e.g. Rickettsia, Chlamydia, Mycoplasma Issues: -discolored teeth in chilldren -superinfections of G.I. -liver damage in pregnant women D. Macrolides: bacteriostatic, inhibits peptide chain elongation, Gram positives E. Streptogramins: bacteriostatic, inhibits peptide chain elongation, Gram positives Issues: -expensive -high incidence of adverse side effects F. Oxazolidinones: bacteriostatic, inhibit ribosomal subunit assembly, Gram positives Last defense for Vancomycin resistant MRSA Issues: -expensive 3. Injury to Plasma Membrane A. Polymyxin B: bactericidal, disrupts structure of membrane, Gram negatives Topical only 4. Inhibitors of Nucleic Acid Synthesis A. Rifamycins: bactericidal, block RNA polymerase to inhibit mRNA synthesis, broad spectrum Penetrates CNS, abscesses, & Mycobacterium Issues: -orange-red body secretions B. Quinolones & Fluoroquinolones: bactericidal, disrupts DNA gyrase, broad spectrum Toxicity: -possible arthropathy in children 5. Competitive Inhibitors of Metabolite Synthesis A. Sulfonamides: bacteriostatic, block folic acid synthesis, broad spectrum Amy Warenda Czura, Ph.D.2SCCC BIO244 Chapter 20 HandoutAntifungal Drugs Fungi = eukaryotes 1. Target membrane sterols (ergosterol) A. Polyenes: permeabilize membrane Toxicity: kidney B. Azoles: inhibit synthesis Toxicity: liver C. Allylamines: inhibit synthesis Topical use 2. Target fungal cell walls A. Echinocandins: inhibit biosynthesis Issues: injection only 3. Target nucleic acids A. Flucytosine: uracil analog Toxicity: kidney & bone marrow Issues: narrow spectrum 4. Other A. Griseofulvin: block microtubule assembly Oral administration for dermatological mycosis, binds keratin Amy Warenda Czura, Ph.D.3SCCC BIO244 Chapter 20 HandoutAntiviral Drugs Virus = obligate intracellular pathogen 1. Nucleoside and Nucleotide analogs: mimic nucleotides, cause mutations in DNA and RNA 2. Enzyme inhibitors: block viral-specific processes A. Neuraminidase inhibitors: block viral separation from host cells B. Protease inhibitors: block virion assembly 3. Interferons: trigger AVP production Amy Warenda Czura, Ph.D.4SCCC BIO244 Chapter 20