Antimicrobial Agents

Antimicrobial Agents

Classify Antimicrobial Agents.
Answer:

Classification Of Antimicrobial Agents

They are classified into many ways:

On Basis Of Chemical Structure

• Sulfonamides and related drugs: Sulfadiazine and others, sulfones-dapsone, para-aminosalicylic acid (PAS).
• Diaminopyrimidines: Trimethoprim, pyrimethamine.
• Quinolone: Nalidixic acid, norflxacin, ciproflxacin, gatiflxacin, etc.
• β­-lactam antibiotics: Penicillins, cephalosporins, monobactams, carbapenems.
• Tetracyclines: Oxytetracycline, doxycycline, etc.
• Nitrobenzene derivatives: Chloramphenicol.
• Aminoglycosides: Streptomycin, gentamycin, amikacin, neomycin, etc.
• Macrolide antibiotics: Erythromycin, clarithromycin, azithromycin, etc.
• Lincosamide antibiotics: Lincomycin, clindamycin.
• Glycopeptide antibiotics: Vancomycin, teicoplanin.
• Oxazolidinones: Linezolid.
• Polypeptide antibiotics: Polymyxin-B, colistin, bacitracin, tyrothricin.
• Nitrofuran derivative: Nitrofurantoin, furazolidone.
• Nitroimidazole: Metronidazole, tinidazole, etc.
• Nicotinic acid derivatives: Isoniazid, pyrazinamide, ethionamide.
• Polyene antibiotics: Nystatin, amphotericin-B, hamycin.
• Azole derivatives: Miconazole, ketoconazole, flconazole.
• Others: Rifampin, spectinomycin, sodium fusidate, cycloserine, viomycin, ethambutol, thiacetazone, clofazimine, and griseofulvin.

On Basis Of Mechanism Of Action

• Inhibit cell wall synthesis: Penicillins, cephalosporins, cycloserine, vancomycin, and bacitracin.
• Cause leakage from cell membranes: Polypeptidespolymyxins, colistin, bacitracin polyenes-amphotericin B, nystatin, hamycin.
• Inhibit protein synthesis: Tetracyclines, chloramphenicol, erythromycin, clindamycin, linezolid.
• Cause misreading of m-RNA code and affect permeability: Aminoglycosides-streptomycin, gentamycin, etc.
• Inhibit DNA gyrase: Fluoroquinolones-ciprofloxacin and others.
• Interfere with DNA function: Rifampin, metronidazole.
• Interfere with DNA synthesis: Acyclovir, zidovudine.
• Interfere with intermediary metabolism: Sulfonamides, sulfones, PAS, trimethoprim, pyrimethamine, ethambutol.

On Basis Of Type Of Organisms Against Which Primarily Active

• Antibacterial: Penicillins, aminoglycosides, erythromycin, etc.
• Antifungal: Griseofulvin, amphotericin B , ketoconazole, etc.
• Antiviral: Acyclovir, amantadine, zidovudine, etc.
• Antiprotozoal: Chloroquine, pyrimethamine, metronidazole, diloxanide, etc.
• Antihelminthic: Mebendazole, pyrantel, niclosamide, diethyl carbamazepine, etc.

 

On Basis Of Spectrum Of Activity

• Narrow-spectrum: Penicillin G, streptomycin, erythromycin
• Broad-spectrum: Tetracyclines, chloramphenicol.

On Basis Of Type Of Action

Primarily bacteriostatic: Sulfonamides, erythromycin, tetracyclines ethambutol, chloramphenicol clindamycin, linezolid

Primarily bactericidal: Penicillins, cephalosporins, aminoglycosides, vancomycin, polypeptides, nalidixic acid, rifampin, ciprofloxacin, isoniazid, metronidazole, pyrazinamide, cotrimoxazole.

Antibiotics Are Obtained From

• Fungi: Penicillin griseofulvin cephalosporin
• Bacterial: Polymyxin B, tyrothricin, colistin, aztreonam, bacitracin
• Actinomycetes: Aminoglycosides, macrolides, tetracyclines, polyenes, chloramphenicol