Updated Principles of Antimicrobials.pptx

Principles of Antibacterials
Classification
Pencillins
cephalosporins
Carbapenems
Beta lactmases
resistance
pharmacokinetic

1. Principles of Antimicrobial Dr. M. Waqas Ilyas Pharm D, M.Phil. Scholar, MBA

2. Antimicrobials are drugs that destroy microbes, prevent their multiplication or growth, or prevent their pathogenic action Differ in their physical, chemical, and pharmacological properties Differ in antibacterial spectrum of activity Differ in their mechanism of action What are Antimicrobials ?

3. According to source : Natural compounds: e.g . penicillin, chloramphenicol . Synthetic compounds: e.g . sulfonamides , quinolones. Semisynthetic compounds: e.g . ampicillin . Classification of Antimicrobials

4. According to the effect on microorganisms: Bactericidal agents: that kills the microorganism e.g . penicillin. Bacteriostatic agents: arrest growth of the microorganism e.g. sulfonamides.

5. According to the effect on microorganisms : Alter nucleic acid metabolism Rifamycins Quinolones Inhibit folate metabolism Trimethoprim Sulfamethoxazole Miscellaneous Metronidazole Daptomycin Inhibit cell wall synthesis Penicillins Cephalosporins Carbapenems Monobactams ( aztreonam ) Vancomycin Inhibit protein synthesis Chloramphenicol Tetracyclines Macrolides Clindamycin Quinupristin / dalfopristin linezolid Aminoglycosides

6. According to antimicrobial spectrum: Narrow spectrum drugs: Drugs affect mainly Gram + ve bacteria e.g. benzyl penicillin. Drugs affect mainly Gram – ve bacteria e.g. aminoglycosides. Extended spectrum drugs: agents that affect Gram + ve & Gram – ve bacteria. Broad spectrum drugs: agents act on wide range of Gram + ve & Gram – ve bacteria and others (protozoa) e.g. tetracyclines .

7. Antimicrobial therapy Empiric Infecting organism(s) not yet identified More “broad spectrum” Definitive Organism(s) identified and specific therapy chosen More “narrow” spectrum Prophylactic or preventative Prevent an initial infection or its recurrence after infection

8. Laboratory Technique Used in the diagnosis of Microbial Disease

9. Minimum I nhibitory Concentration (MIC) The lowest concentration of drug that prevents visible bacterial growth after 24 hours of incubation in a specified growth medium Organism and antimicrobial specific Minimum Bactericidal Concentration ( MBC ) The lowest concentration of drug that results in 99.9% decline in colony count after overnight broth dilution incubations.

10. Factors: Lipid Solubility Molecular Weight Protein Binding Susceptibility to transporters of efflux pump

11. In transformation a bacterium takes up a piece of DNA floating in its environment, In Transduction DNA is moved from one bacterium to other by virus. In Conjugation DNA is transferred between bacteria through direct contact (through a tube between cells).