antibiotics

• Antibacterial


  An agent that kills or inhibits the growth of micro organisms
• Types of antibacterial


  • Bacteriostatic - stop bacterial growth
  • Bactericidal - kill bacteria
• Classification of antibacterials


  • Cell wall synthesis inhibitors
  • Protein synthesis inhibitors
  • Nucleic acid synthesis inhibitors
  • Folate antagonists
• Cell wall synthesis inhibitors


  • Beta lactam antibiotics
  • Vancomycin
  • Bacitracin
• Protein synthesis inhibitors


  • Tetracyclines
  • Aminoglycosides
  • Macrolides
  • Chloramphenicol
• Nucleic acid synthesis inhibitors


  • Quinolones
• Folate antagonists


  • Sulphonamides
  • Trimethoprim
  • Co-trimoxazole
• Beta lactam antibiotics


  • Penicillins
  • Cephalosporins
  • Monobactams
  • Carbapenems
• Penicillins


  • Inhibit bacterial cell wall synthesis
  • Bactericidal
• Types of penicillins


  • Natural penicillins
  • Penicillinase resistant penicillins
  • Aminopenicillins
• Indications for penicillins


  • Streptococcal infection
  • Staphylococcal infection
  • Pneumococcal infection
  • Syphilis and Gonorrhea
  • Meningococcal meningitis
  • Typhoid fever
  • Gangrene
• Adverse effects of penicillins


  • Hypersensitivity
  • Nephrotoxicity
  • Nausea, vomiting, diarrhoea
• Cephalosporins


  Beta-lactam antibiotics similar to penicillins in their mode of action but more resistant to Beta-lactamase
• Generations of cephalosporins


  • First generation
  • Second generation
  • Third generation
• First generation cephalosporins


  Cefazolin, Cefalexin, Cefadroxil
• Second generation cephalosporins


  Cefaclor, Cefuroxime
• Third generation cephalosporins


  Ceftriaxone, Cefotaxime, Cefixime, Cefpodoxime
• Adverse effects of cephalosporins


  • Hypersensitivity reactions
  • Nephrotoxicity
  • Local irritation and thrombophlebitis
• Carbapenems


  Broadest spectrum Beta-lactam antibiotics, effective against Gram-positive, Gram-negative organisms and Anaerobes, resistant to Beta-lactamase
• Monobactams


  Narrow spectrum, effective against aerobic Gram-negative organisms, resistant to Beta-lactamases
• Beta-lactamase inhibitors


  Clavulanic acid, Sulbactam, Tazobactam - do not have antibacterial effect but inhibit Beta-lactamase to protect antibiotics
• Vancomycin


  Inhibits cell wall synthesis at an earlier stage than Beta-lactam antibiotics, effective against Gram-negative organisms
• Indications for vancomycin


  • Methicillin-resistant Staph aureus
  • Patients with serious allergy to Beta-lactam antibiotics
  • Antibiotic-induced Pseudomembranous colitis
• Adverse effects of vancomycin


  • Fever, chills, phlebitis
  • Shock with rapid infusion
  • Hearing affection or loss
  • Renal dysfunction
• Protein synthesis inhibitors


  • Tetracyclines
  • Aminoglycosides
  • Macrolides
  • Chloramphenicol
• Tetracyclines


  Bind to 30S ribosomal bacterial subunits leading to inhibition of protein synthesis, bacteriostatic
• Tetracycline uses


  • Chlamydia infections
  • Amebiasis
  • Acne
  • Mycoplasma pneumonia
  • Cholera
  • Meningococcal carriers
• Tetracycline adverse effects


  • Epigastric pain
  • Teeth discoloration and bone hypoplasia
  • Hepatotoxicity
  • Phototoxicity
  • Fanconi syndrome
• Tetracycline contraindications


  • Renal dysfunction (except doxycycline)
  • Pregnancy and lactation
  • Children
• Aminoglycosides


  Irreversible binding with 30S ribosomal bacterial subunits leading to inhibition of protein synthesis, bactericidal
• Aminoglycoside members


  • Streptomycin
  • Gentamycin
  • Tobramycin
  • Amikacin
  • Netilmicin
  • Neomycin
• Aminoglycoside adverse effects


  • Nephrotoxicity
  • Ototoxicity
  • Neuromuscular paralysis
  • Allergy
• Macrolides


  Bacteriostatic, bind with 50S ribosomal subunits leading to inhibition of protein synthesis
• Macrolide members


  • Erythromycin
  • Clarithromycin
  • Azithromycin
  • Roxithromycin
• Macrolide uses


  • Chlamydia
  • Mycoplasma
  • Spirochetes
  • Gram-positive cocci and bacilli
  • First choice for penicillin allergy
  • Urogenital infection in pregnancy
  • Mycoplasma pneumonia in children
• Macrolide adverse effects


  • Epigastric pain and GIT distress
  • Cholestatic jaundice
  • Ototoxicity
  • Thrombophlebitis
• Macrolides are contraindicated in liver disease
• Macrolides can increase plasma levels of Theophyllin, Warfarin, Carbamazepine, Terfenadine and Digoxin
• Chloramphenicol


  Bacteriostatic, binds to 50S ribosomal subunits leading to inhibition of protein synthesis
• Chloramphenicol uses


  • Typhoid fever
  • Bacterial meningitis
  • Anaerobic infection