Antibiotic

• What are the main topics covered in the study material on antibiotics?

  • Overview
  • History of antibiotics
  • Problems with antibiotic use
  • How antibiotics are used
  • Antibiotic pharmacology
  • Common classes of drug
  • Mechanisms of resistance
• What was the significance of Robert Austrian's statement in 1964 regarding antibiotics?

  He referred to antibiotics as a miracle in medicine.
• What did William Stewart, the US Surgeon General, declare in 1967 about infectious diseases?

  He claimed we have basically wiped out infection.
• How has repeated exposure to antibiotics affected resistance?

  It has greatly increased resistance due to selection pressure.
• How many antibiotics are currently in Phase 2/3 development?

  Only 7 antibiotics.
• What is the role of antibiotic stewardship?

  To reduce antibiotic consumption and promote logical choices.
• What are the types of antibiotic therapy mentioned in the study material?

  • Guided therapy
  • Empirical therapy
  • Prophylactic therapy
• What does guided therapy depend on?

  Identifying the cause of infection and selecting the agent based on sensitivity testing.
• When is empirical therapy used?

  When therapy cannot wait for culture results.
• What is the purpose of prophylactic therapy?

  To prevent infection before it begins.
• What are the ideal characteristics of antibiotics?

  • Highly toxic to bacteria causing infection
  • Penetrate the affected body area
  • Limit release of toxins from bacteria
  • Convenient administration
  • Non-toxic to the patient
  • Limited effect on colonizing bacteria
• What is the compromise in guided therapy?

  Using antibiotics with limited action to the bacteria causing infection.
• What is the example of guided therapy provided in the study material?

  An 86-year-old woman with dysuria and E. coli infection.
• What was the treatment selected for the 86-year-old woman with E. coli infection?

  Nitrofurantoin, a narrow-spectrum antibiotic.
• What was the situation of the 26-year-old man requiring empirical therapy?

  He was admitted with fever, respiratory failure, and sepsis.
• What combination therapy was used for the 26-year-old man?

  Co-amoxiclav and clarithromycin.
• What was identified in the blood culture after 24 hours for the 26-year-old man?

  Streptococcus pneumoniae, a Gram-positive diplococcus.
• What is the difference between bactericidal and bacteriostatic antibiotics?

  Bactericidal antibiotics kill bacteria, while bacteriostatic antibiotics suppress their growth.
• What are the principal mechanisms of antibiotic resistance?

  1. Mutation/modification of target site
  2. Inactivating enzymes
  3. Limit access: reduced permeability and increased efflux
• What are the first members of the beta-lactam group of antibiotics?

  Penicillins
• What is the role of beta-lactamase inhibitors?

  They help overcome beta-lactamase stable drugs.
• What are the classes of antibiotics mentioned in the study material?

  • Penicillins
  • Cephalosporins
  • Carbapenems
  • Glycopeptides
  • Macrolides
  • Aminoglycosides
  • Quinolones
  • Tetracyclines
  • Sulphonamides
  • Chloramphenicol
• What is the summary of the antibiotic study material?

  • Antibiotics offer reliable cures for bacterial infections.
  • Resistance is a major problem.
  • Pan-resistant Gram-negative strains are emerging.
  • Knowledge of antimicrobial pharmacology is crucial for rational selection.
• What are antibiotics?

  Compounds that either kill or inhibit the growth of bacteria
• How can the mechanisms of action of antibiotics be classified?

  Based on the cellular structures or processes they target in bacteria
• What are the key classes of antibiotics?

  • Cell wall inhibitors
  • Protein synthesis inhibitors
  • DNA replication inhibitors
  • Metabolism inhibitors
• What do beta-lactam antibiotics include?

  Penicillins, cephalosporins, carbapenems, and monobactams
• What is crucial for the antibacterial activity of beta-lactam antibiotics?

  The beta-lactam ring
• What do beta-lactam antibiotics primarily target?

  The bacterial cell wall, inhibiting its synthesis
• What is the result of inhibiting bacterial cell wall synthesis by beta-lactam antibiotics?

  Cell lysis and death
• How do penicillins work?

  By binding to penicillin-binding proteins (PBPs)
• How are cephalosporins classified?

  Into generations (1st to 4th) based on their spectrum of activity
• What is the spectrum of activity of later generations of cephalosporins?

  Increased activity against gram-negative bacteria
• What type of bacteria does vancomycin target?

  Gram-positive bacteria
• Why is vancomycin especially useful?

  It is effective against penicillin-resistant bacteria like MRSA
• How do bacteria develop resistance to beta-lactams?

  Through the production of beta-lactamases
• What can be used to overcome beta-lactam resistance?

  Beta-lactamase inhibitors like clavulanic acid
• What do protein synthesis inhibitors target?

  The bacterial ribosome
• What is the effect of doxycycline on protein synthesis?

  It blocks the attachment of aminoacyl-tRNA to the ribosome
• What does chloramphenicol inhibit during protein synthesis?

  The formation of peptide bonds