Antimicrobial Agents

Antimicrobial Agents

Question 1. Classify Antimicrobial Agents Based On Their Mechanism Of Action.
Answer:

Classification Of Antimicrobial Agents Based On Mechanism Of Action

• Inhibit cell wall synthesis: Penicillins, cephalosporins, cycloserine, vancomycin, and bacitracin.
• Cause leakage from cell membranes: Polypeptidespolymyxins, colistin, bacitracin polyene amphotericin B, nystatin, hamycin.
• Inhibit protein synthesis: Tetracyclines, chloramphenicol, erythromycin, clindamycin, linezolid.
• Cause misreading of m­RNA code and affect permeability: Aminoglycosides-Streptomycin, Gentamycin, etc.
• Inhibit DNA gyrase: Fluoroquinolones-Ciproflxacin and others.
• Interfere with DNA function: Rifampin, Metronidazole.
• Interfere with DNA synthesis: Acyclovir, Zidovudine.
• Interfere with intermediary metabolism: Sulfo amides, sulfones, para-aminosalicylic acid (PAS), trimethoprim, pyrimethamine, ethambutol.

Question 2. Write An Account Of Drug Induced Superinfections And Its Management.
Answer:

• Superinfection refers to the appearance of a new infection as a result of antimicrobial therapy for another infection.
• The etiologic organism of superinfection is different from that of the primary disease.
• Most of the antimicrobial drugs mainly broad-spectrum antibiotics, ampicillin, etc. cause alteration of normal bacterial flora due to which host defense mechanism becomes impaired. Now the pathogenic microorganism invades the host, multiplies, and leads to superinfection.

Following Are The Drug-Induced Super Infections And Their Management:

• Candida albicans leads to oral thrush, monilial diarrhea, and vulvovaginitis which is treated with nystatin or clotrimazole.
• Resistant staphylococci lead to enteritis which is treated by cloxacillin, vancomycin, and linezolid.
• Clostridium difficile leads to pseudomembranous enterocolitis associated with the use of clindamycin, tetracycline, aminoglycosides, ampicillin, cotrimoxazole for treating this metronidazole and vancomycin are the drugs of choice.
• Proteus leads to UTI and enteritis which is treated with cephalosporin or gentamicin.
• Pseudomonas leads to UTI and enteritis which is treated with carbenicillin, piperacillin, and gentamycin.