Classification of Antibiotics Based on Mechanism of Action
Antibiotics are essential medicines used to prevent and treat bacterial infections. They are classified based on how they act on bacterial cells. Understanding these mechanisms is crucial for healthcare professionals, pharmacists, and students to choose the right antibiotic and combat resistance.
1. Inhibitors of Cell Wall Synthesis
These antibiotics block peptidoglycan synthesis, weakening bacterial cell walls and leading to cell death.
- Examples: Penicillins, Cephalosporins, Carbapenems, Monobactams, Vancomycin, Bacitracin
2. Inhibitors of Protein Synthesis
They prevent bacteria from making proteins by targeting ribosomal subunits.
- 30S Subunit Inhibitors: Aminoglycosides (Gentamicin), Tetracyclines (Doxycycline)
- 50S Subunit Inhibitors: Macrolides (Erythromycin, Azithromycin), Chloramphenicol, Clindamycin, Linezolid
3. Inhibitors of Nucleic Acid Synthesis or Function
These drugs interfere with DNA replication or RNA transcription.
- Examples: Fluoroquinolones (Ciprofloxacin), Rifamycins (Rifampicin), Metronidazole
4. Inhibitors of Metabolic Pathways (Antimetabolites)
They block bacterial folate synthesis, preventing nucleic acid production.
- Examples: Sulfonamides, Trimethoprim, Co-trimoxazole
5. Disruptors of Cell Membrane Function
These agents damage bacterial cell membranes, causing leakage of contents.
- Examples: Polymyxins (Polymyxin B, Colistin), Daptomycin
Quick Table
| Mechanism | Examples | Target |
|---|---|---|
| Inhibit cell wall synthesis | Penicillins, Cephalosporins, Vancomycin | Peptidoglycan |
| Inhibit protein synthesis (30S) | Aminoglycosides, Tetracyclines | 30S ribosomal subunit |
| Inhibit protein synthesis (50S) | Macrolides, Chloramphenicol | 50S ribosomal subunit |
| Inhibit nucleic acid synthesis | Fluoroquinolones, Rifampicin | DNA/RNA synthesis |
| Inhibit metabolic pathways | Sulfonamides, Trimethoprim | Folate pathway |
| Damage cell membrane | Polymyxins, Daptomycin | Cell membrane integrity |
Summary
Antibiotics are classified into five major groups based on their action: those that inhibit cell wall synthesis, protein synthesis, nucleic acid synthesis, metabolic pathways, or damage the bacterial cell membrane. This classification is essential for effective treatment and fighting antibiotic resistance.
