Pharmacology of Antibacterial Agents

Classification of Antibacterial Agents

• Bacteriostatic agents: Inhibit bacterial growth and multiplication, but do not kill bacteria. Examples:
  • Sulfonamides
  • Tetracyclines
  • Macrolides
  • Chloramphenicol
• Bactericidal agents: Kill bacteria. Examples:
  • Beta-lactam antibiotics (penicillins, cephalosporins, carbapenems)
  • Aminoglycosides
  • Fluoroquinolones
  • Metronidazole

Mechanisms of Action

• Inhibition of cell wall synthesis: Beta-lactam antibiotics
• Inhibition of protein synthesis: Tetracyclines, Macrolides, Aminoglycosides
• Inhibition of DNA replication: Fluoroquinolones
• Disruption of membrane structure: Polymyxins
• Inhibition of folic acid synthesis: Sulfonamides

Spectrum of Activity

• Narrow-spectrum agents: Effective against a limited range of bacteria. Examples:
  • Penicillin G (streptococci, some staphylococci)
  • Macrolides (streptococci, staphylococci, Haemophilus)
• Broad-spectrum agents: Effective against a wide range of bacteria. Examples:
  • Tetracyclines
  • Fluoroquinolones
  • Beta-lactam/beta-lactamase inhibitor combinations

Resistance to Antibacterial Agents

• Mechanisms of resistance:
  • Enzymatic degradation of antibiotics (beta-lactamases)
  • Alteration of target molecules
  • Reduced permeability of bacterial cells
  • Active efflux of antibiotics
• Factors contributing to resistance:
  • Overuse and misuse of antibiotics
  • Selection pressure
  • Horizontal gene transfer

Classification of Antibacterial Agents

• Bacteriostatic agents inhibit bacterial growth and multiplication, but do not kill bacteria, examples include Sulfonamides, Tetracyclines, Macrolides, and Chloramphenicol.
• Bactericidal agents kill bacteria, examples include Beta-lactam antibiotics, Aminoglycosides, Fluoroquinolones, and Metronidazole.

Mechanisms of Action

• Beta-lactam antibiotics inhibit cell wall synthesis.
• Tetracyclines, Macrolides, and Aminoglycosides inhibit protein synthesis.
• Fluoroquinolones inhibit DNA replication.
• Polymyxins disrupt membrane structure.
• Sulfonamides inhibit folic acid synthesis.

Spectrum of Activity

• Narrow-spectrum agents are effective against a limited range of bacteria, examples include Penicillin G (effective against streptococci, some staphylococci) and Macrolides (effective against streptococci, staphylococci, Haemophilus).
• Broad-spectrum agents are effective against a wide range of bacteria, examples include Tetracyclines, Fluoroquinolones, and Beta-lactam/beta-lactamase inhibitor combinations.

Resistance to Antibacterial Agents

• Mechanisms of resistance include enzymatic degradation of antibiotics, alteration of target molecules, reduced permeability of bacterial cells, and active efflux of antibiotics.
• Factors contributing to resistance include overuse and misuse of antibiotics, selection pressure, and horizontal gene transfer.

This quiz covers the classification of antibacterial agents, including bacteriostatic and bactericidal agents, and their mechanisms of action.