II. Background

  1. Penicillin first discovered by Alexander Fleming in 1928
    1. Observed inhibited growth of Staphylococcus on an agar plate
    2. Agar was contaminated with growth of Penicillium mold
  2. Penicillin was first introduced to pharmaceutical market in 1946

IV. Mechanism

  1. Penicillin inhibits cell wall synthesis
  2. All Penicillins contain a beta lactam ring central to their functionality
    1. Beta lactam ring is also found in Cephalosporins and carbopenems
    2. In addition, all Penicillins also have a thiazoldine ring and a side chain
  3. Beta lactam ring binds Penicillin binding Protein, which interferes with peptidoglycan synthesis
    1. Inhibition of peptidoglycan synthesis blocks cross-linking of the Bacterial cell wall components
  4. Extended spectrum agents include additional side chains to combat resistance
    1. Bulky side chains decrease Penicillinase resistance

V. Mechanism: Penicillin Resistance Mechanisms

  1. Bacterial Production of Beta lactamase
    1. Staphylococcus aureus
    2. Staphylococcus epidermidis
    3. Neisseria gonorrhoeae
    4. Moraxella catarrhalis
  2. Bacterial Alteration in Penicillin-binding Proteins
    1. Streptococcus Pneumoniae (Pneumococcus)

VI. Adverse Effects

  1. Anaphylaxis and other Hypersensitivity Reactions
  2. Nephritis
  3. Hyperkalemia
  4. Neutropenia
  5. Seizures
    1. Beta Lactam ring is similar to GABA and may inhibit GABA activity

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Related Studies

Cost: Medications

penicillin (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
PENICILLIN VK 125 MG/5 ML SOLN Generic $0.07 per ml
PENICILLIN VK 250 MG TABLET Generic $0.06 each
PENICILLIN VK 250 MG/5 ML SOLN Generic $0.05 per ml
PENICILLIN VK 500 MG TABLET Generic $0.10 each