Antimicrobials

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Antimicrobials

• Julie Balk NP, MS
• Nursing 220

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Antimicrobial Choices

• Drugs that weaken the cell wall
• Drugs that are bacteriostatic inhibitors of
  protein synthesis
• Drugs that are bactericidal inhibitors of protein
  synthesis
• Drugs that suppress bacterial growth by
  inhibition of folic acid synthesis
• Miscellaneous Antibacterials
• Antifungal Agents

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Agents that work on the cell wall

• Penicillins
• Cephalosporins
• Carbapenems
• Aztreonam
• Vancomycin
• Teicoplanin
• Fosfomycin

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Penicillins (PCNs)

• MOAWeaken cell wall causing the bacteria to take
  up excessive amounts of water and causing
  cellular rupture
• Cell wall weakened by
• 1) Inhibition of transpeptidases
• 2) Disinhibition (activation) of autolysins
• Due to the MOA PCNs are usually bacteriocidal

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PCN Resistance

• Mechanisms of Resistance
• Inability of Pcns to reach their targets (PBP)
• Inactivation of Pcns by bacterial enzymes
  (Beta-lactamases)

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Classification of PCNs

• Based of antimicrobial spectrum
• Narrow spectrum that are penicillinase sensitive
• Narrow spectrum that are penicillinase resistant
  (antistaph pcns)
• Broad spectrum pcns (aminopenicillins)
• Extended spectrum pcns

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Narrow Spectrum Penicillinase Sensitive

• Penicillin G
• Penicillin V
• Absorption, Distribution, Elimination
• Side Effects and Toxicities
• Allergies
• Drug Interactions

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Penicillinase-Resistant Penicillins(Antistapylocc
al Penicillins)

• Nafcillin
• Oxacillin
• Cloxacillin
• Dicloxacillin
• S. aureus
• Staph. epidermidis

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Broad-Spectrum Penicillins(Aminopenicillins)

• Ampicillin
• Amoxicillin
• Bacampicillin
• Same spectrum as penicillin G plus increased
  activity agains gram-negative bacilli including
  H. Flu, E. coli, Salmonella and Shigella

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Extended-Spectrum Penicillins(Antipseudomonal
Penicillins)

• Ticarcillin
• Carbenicillin
• Indanyl
• Mezlocillin
• Piperacillin
• Same spectrum of aminopenicillins plus Pseudomas
  aeruginosa, Enterobacter, Proteus, B. Frag,
  Klebsiella
• Ineffective against most strains of S. aureus

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Penicillins combined with a Beta-Lactamase
Inhibitor

• Ampicillin Sulbactam Unasyn
• Amoxicillin clavulanic acidAugmentin
• Ticarcillin clavulanic acidTimentin
• Peperacillin TazoactamZosyn

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Cephalosporins

• Bactericidal
• Broad Spectrum
• Low toxicity
• Most widely used group of antibiotics
• Classifications
• 1st Generation 4th Generation

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Cephalosporins

• Absorption
• Distribution
• Elimination
• Adverse Effects
• Allergic Considerations
• Bleeding
• Thrombophlebitis
• Drug Interactions

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Cephalosporin Generations

• 1st Generation
• 2nd Generation
• 3rd Generation
• 4th Generation

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Carbapenems

• Imipenem
• Meropenem
• Ertapenem
• Spectrum
• Special Considerations

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Other Inhibitors of Cell Wall Synthesis

• Aztreonam
• Vancomycin
• Therapeutic Uses PO vs IV
• Adverse Effects
• Resistance Issues

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Bacteriostatic Inhibitors of Protein Synthesis

• Tetracyclines
• Macrolides
• Clindamycin
• Chloramphenicol
• Linezolid
• Dalfopristin/Quinupristin
• Spectinomycin

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Tetracyclines

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects

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Marolides

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects

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Clindamycin

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects

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Chloramphenicol

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects

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Linezolid

• Mechanism of Action
• Spectrum
• Therapuetic Uses
• Adverse Effects

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Dalfosristin/Quinupristin

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects

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Aminoglycosides Bactericidal Inhibitors of
Protein Synthesis

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects
• Gentamicin, Tobramycin, Amikacin others

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Sulfonamides and Trimethoprim

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects
• Trimethoprim, Trimethoprim-Sulamethoxazole

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Fluroquinolones

• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects

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Micellaneous Antibacterials

• Antimycobacterial Agents
• Tuberculosis, Leprosy, Mycobacterium avium
• Metronidazole
• Rifampin
• Bacitracin
• Polymyxins

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Antifungal Agents

• Systemic Mycoses
• Amphotericin B, Ketoconazole, Itraconazole,
  Fluconazole, Miconazole, Voriconazole,
  Flucytosine, Caspofungin
• Superificial Mycoses
• Azoles Clotrimazole, Ketoconazole
• Others

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Systemic Mycoses

• Amphotericin B
• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects
• AzolesItraconizole, Voriconizole
• EchinocandinsCaspofungin, Micafungin

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Superficial Mycoses

• Dermatophytic Infections, Canididiasis,
  Onychomycisis
• Azoles
• Mechanism of Action
• Spectrum
• Therapeutic Uses
• Adverse Effects
• Polyene Antibiotics

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