Antibiotics: Inhibitors of Cell Wall Biosynthesis

Inhibitors of Cell Wall Biosynthesis

• Penicillins:
  • Benzylpenicillin (penicillin G) administered by injection
  • Procaine benzylpenicillin reduces pain and discomfort when administered intramuscularly
  • Benzathine penicillin is a long-acting penicillin injection
  • Penicillin G is used to treat syphilis and rheumatic fever
• Cephalosporins:
  • First-generation: Cefazolin for surgical prophylaxis
  • Second-generation: Cefuroxime increases coverage against Haemophilus influenza
  • Third-generation: Ceftriaxone or cefotaxime for meningitis, and Ceftazidime for Pseudomonas aeruginosa coverage
  • Fourth-generation: Cefepime for meningitis and Pseudomonas aeruginosa coverage
  • Fifth-generation: Ceftaroline for methicillin-resistant Staphylococcus aureus (MRSA)
• Glycopeptides:
  • Vancomycin active against Gram-positive bacteria, MRSA, and Clostridium difficile
  • Used for antibiotic-induced pseudomembranous colitis

Inhibitors of Cell Membrane Function

• Colistin is a last-reserve option for multidrug-resistant bacteria

Inhibitors of Protein Synthesis (30S Subunit Ribosome)

• Tetracyclines:
  • Used for acne treatment
  • Used for Upper Respiratory Tract Infections in penicillin-allergic patients
• Aminoglycosides:
  • Neomycin and tobramycin for skin and eye infections
  • Gentamicin active against Pseudomonas aeruginosa
  • Streptomycin used for tuberculosis treatment
  • Neomycin orally for hepatic encephalopathy
  • Kanamycin as a second-line drug for tuberculosis
  • Paromomycin for acute bacillary dysentery
  • Spectinomycin active against Neisseria gonorrhea

Inhibitors of Protein Synthesis (50S Subunit Ribosome)

• Macrolides:
  • Used for pneumonia, pharyngitis, and tonsillitis
  • Clarithromycin for Helicobacter pylori infections
  • Used for sexually transmitted infections and atypical pneumonia
  • Used for Upper Respiratory Tract Infections in penicillin-allergic patients
• Lincosamides:
  • Used for acne vulgaris and bacterial vaginosis
  • Clindamycin for prophylactic coverage against endocarditis
  • Used for anthrax and malaria
  • Effective against MRSA in soft tissue infections
• Chloramphenicol:
  • Used for eye and ear infections
  • Alternative for meningitis and typhoid treatment
• Fusidic acid:
  • Used for skin and eye bacterial infections
  • Can be combined with steroids in creams

Inhibitors of Nucleic Acid Synthesis

• Inhibitors of DNA Synthesis:
  • Quinolones: used for urinary tract infections
• Inhibitors of RNA Synthesis:
  • Rifampin (Rifampicin):
    • Active against Mycobacterium tuberculosis, Mycobacterium leprae, and Clostridium difficile
    • Used prophylactically to prevent TB in high-risk groups
  • Used alongside other drugs for TB treatment
• Inhibitors of Folate Synthesis:
  • Sulphonamides:
    • Competitive inhibitors of folic acid metabolism
    • Combination with trimethoprim for urinary tract infections and upper respiratory tract infections

Antibacterial Agents with Other Mechanisms

• Nitrofuran antibiotics:
  • Nitrofurantoin (Uvamine Capsule) used for urinary tract infections
• Daptomycin:
  • Active against Gram-positive bacteria, including MRSA
  • Used for diabetic foot infections and prosthetic joint infections
• Metronidazole:
  • Used for diarrhea due to intestinal amebiasis and bacterial vaginosis