Principles of antibiotics use Flashcards
Cell wall synthesis antibiotics (8)
Cycloserine Vancomycin Bacitracin Fosftomycin Penicillins Cephalosporins Manobactams Carbapenems
Protein Synthesis antibiotics (3) 50S inhibitors
Erythromycin
Chloramphenicol
Clindamycin
Protein Synthesis antibiotics (5) 30S
Tetracycline Spectinomycin Streptomycin Gentamicin, tobramycin Amikacin
Susceptible
Concentration of drug can be achieved AT THE SITE OF INFECTION that inhibits organism and is below level of toxicity for human cells.
Resistant
Inhibitory or bactericidal concentration exceeds that which can be achieved safely
Protein Synthesis inhibitors are…. and the exception is…
Bacteriostatic.
Exception: Aminoglycosides (bactericidal)
Cell wall active agents are …
Bactericidal
Rifampin and quinolone are
Bactericidal
What is bacteriostatic?
Those are agents that inhibit the bacterial growth but does not kill the cells. KEEPS THE GRAPH STATIC
What is bactericidal?
Those are agents that actually reduce the number of bacterial cells. DECLINES THE GRAPH
MIC
Minimum inhibitory concentration. Minimum concentration of antibiotics needed to inhibit the bacterial growth.
MBC
Minimum bactericidal concentration. Minimum concentration of antibiotics needed to kill the bacteria.
If MIC is within the therapeutic range of drug, but MBC is not then the drug is…
Bacteriostatic
If MBC is within the therapeutic range of drug then the drug is…
Bactericidal
When is prophylaxis treatment used?
At the “No infection” point of the timeline. Before the infection has occurred.
When is Empiric treatment used?
After symptoms have begun but no pathogen isolation has occurred. Example: Using broad-spectrum agent or combination therapy (if its life threatening)
What should be done BEFORE starting empiric treatment?
Cultures of site of infection and blood should be taken.
When is definitive treatment used?
Once the pathogen is isolated then definitive treatment can be used. Example: specific narrow-spectrum agent
What are the benefits of combination therapy? (5)
1) empirical therapy of severe infection
2) treatment of polymicrobial infections
3) enhance antimicrobial activity for specific infection
4) prevent emergence of resistance
5) reduce toxicity to host
Bacteriostatic antibiotics frequently ——— action of bactericidal ones. (example?)
Antagonize
Example: tetracyclines antagonize B-lactams
Bactericidal antibiotics in combination tend to be ——— or ——–. (example?)
Additive or synergistic
Cell wall synthesis inhibitor plus aminoglycoside
