Antimicrobial drugs

  • There are many basis for classifiaction of antimicrobial drugs
CHEMICAL STRUCTURE:

Quinolones Nalidixic acid,
Norfloxacin
Ciprofloxacin etc
Macrolide antibiotics Erythromycin,
Tacrolimus(Fk-506)
Roxithromycin,
Azithromycin
Polypeptide antibiotics Polymyxin-B, Colistin
Bacitracin
Glycopeptides Vancomycin
Teicoplanin
Oxazolidinone Linezolid
Nitrofuran derivatives Nitrofurantoin
Furazolidone
Nitroimidazoles Metronidazole
Tinidazole
Nicotinic acid derivatives Isoniazid,
Pyrazinamide
Ethionamide
Polyene antibiotics Nystatin
Hamycin
Amphotericin-B
Azole derivatives Miconazole,
Clotrimazole,
Ketoconazole
Fluconazole
Others Rifampin,
Lincomycin,
Clindamycin,
Spectinomycin
Sod. Fusidate,
Cycloserine,
Ethambutol
Clofazimine
Griseofulvin
MECHANISM OF ACTION:

Inhibit cell wall synthesis Penicillins,
Cephalosporins,
Aztreonam
Cycloserine,
Vancomycin,
Bacitracin
Cause leakage from cell membranes Polypeptides - Polymyxins,Colistin,Bacitracin
Polyenes-Amphotericin B, Nystatin, Hamycin Polyenes-Amphotericin B, Nystatin, Hamycin
Inhibit protein synthesis Tetracyclines,
Linezolid,
Chloramphenicol
Erythromycin,
Clindamycin
Cause misreading of m-RNA code & affect permeability Aminoglycosides- Streptomycin, Gentamicin
Inhibit DNA gyrase Fluoroquinolones – Ciprofloxacin
Interfere with DNA function Rifampin,
Metronidazole
Interfere with DNA synthesis Idoxuridine, Acyclovir, Zidovudine
Interfere with intermediary metabolism Sulfonamides, Sulfones
PAS, Trimethoprim,
Pyrimethamine, Ethambutol.
TYPE OF ORGANISMS AGAINST WHICH PRIMARILY ACTIVE:

Antibacterial Penicillins, Aminoglycosides, Erythromycin etc
Antifungal Griseofulvin, Amphotericin B, Ketoconazole etc.
Antiviral Idoxuridine, Acyclovir, Amantadine, Zidovudine etc
Antiprotozoal Chloroquine, Pyrimethamine, Metronidazole, Diloxanide etc.
Anthelmintic Mebendazole, Pyrantel, Niclosamide, Diethyl carbamazine etc.
SPECTRUM OF ACTIVITY:

Narrow spectrum Broad spectrum
Penicillin
GStreptomycin
Erythromycin
Tetracyclines
Chloramphenicol
ACTION:

Primarily bacteriostatic Primarily bactericidal
Sulfonamides
Tetracyclines
Chloramphenicol
Erythromycin
Ethambutol
Penicillins
Aminoglycosides
Polypeptides
Rifampin
Cotrimoxazole
Cephalosporins
Vancomycin
Nalidixic acid
Ciprofloxacin
ANTIBIOTICS ARE OBTAINED FROM:

Fungi Bacteria Actinomycetes
Penicillin,
Cephalosporin
,Griseofulvin
Poymyxin B
Bacitracin,
Tyrothricin
Aztreonam
Aminoglycosides,
Tetracyclines,
Polyenes
Chloramphenicol
Macrolides.
Exam Question

  • Vancomycin,Aztreonam & Cephalexin inhibit bacterial cell wall synthesis
  • Bacteriocidal agents includes cephalosporin
  • Antipseudomonal action is a characteristic of Cefoperazone
  • Tacrolimus(Fk-506) is macrolide antibiotic
  • Tetracycline, Chloramphenicol, Erythromycin inhibit protein synthesis
  • Bacteriostatic anti TB drug Ethambutol
Don't Forget to Solve all the previous Year Question asked on Antimicrobial drugs