Antibiotics and Their Usage

Antibiotics

• Antibiotics are chemical substances derived from microorganisms that can inhibit or kill bacteria.

Types of Antibiotics

• Broad Spectrum Antibiotics: effective against many species of bacteria
• Narrow Spectrum Antibiotics: effective against a few species of bacteria

Mechanism of Action

• Bactericidal: kills bacteria
  • Inhibits synthesis of bacterial cell wall
  • Inhibits synthesis of protein and nucleic acid
  • Disrupts chemical activity in bacteria
• Bacteriostatic: inhibits growth of bacteria
  • Inhibits synthesis of protein
  • Inhibits synthesis of folic acid (vitamin for brain)

General Indications

• Treats bacterial infections
• Dosage and duration of treatment vary depending on the type of infection and the patient's condition

Misuse of Antibiotics

• Using antibiotics for non-bacterial infections
• Self-medication with antibiotics
• Not completing the full dosage or taking antibiotics for the wrong duration
• Can lead to antibiotic resistance

Side Effects

• Hypersensitivity
• Gastrointestinal disturbances
• Destruction of normal flora (mouth, gut, and genital areas)
• Liver and kidney damage (with high doses or long-term use)

Types of Antibiotics

• Penicillins
  • Broad Spectrum (Gram +ve)
  • Bactericidal and Bacteriostatic
  • Destroys bacterial cell wall
  • Causes bacterial cells to swell, rupture, and die
• Cephalosporins
  • Broad Spectrum (Gram +ve and Gram -ve)
  • Bactericidal and Bacteriostatic
  • Inhibits synthesis of bacterial cell wall
• Tetracyclines
  • Broad Spectrum (Gram +ve and Gram -ve)
  • Bacteriostatic
  • Inhibits protein synthesis in bacteria

Penicillins

• Natural Penicillins: Benzylpenicillin (Penicillin G), Phenoxymethyl Penicillin (Penicillin V)
• Semisynthetic Penicillins
• Indications: Urinary tract infections, Respiratory tract infections, Skin infections, Meningitis, Intra-abdominal infections, Gonorrhea, Syphilis

Cephalosporins

• Ceftazidime (Fortum)
• Indications: Urinary tract infections, Respiratory tract infections, Skin infections, Meningitis
• Dose: Adult: 1g q 8 hr IM/IV or 2g q 12 hr IM/IV
• Side Effects: Hypersensitivity, Nausea, Vomiting, Diarrhea, Nephrotoxicity

Tetracyclines

• Doxycycline (Vibramycin)
• Indications: Urinary tract infections, Skin infections, Respiratory tract infections, Typhus fever
• Dose: Adult: 200mg PO on day 1, followed by 100mg/d PO
• Side Effects: Hypersensitivity, Nausea, Vomiting, Diarrhea, Photosensitivity

This quiz covers the effects, side effects, and usage of antibiotics, including examples, doses, and administration. It also explores indications and contraindications of antibiotic use.