Antimicrobial Pharmacology - Basics & Background Flashcards
Are macrolides bacteriostatic or bacteriocidal?
Bacteriostatic
Are tetracyclines bacteriostatic or bacteriocidal?
Bacteriostatic
Is clindamycin bacteriostatic or bacteriocidal?
Bacteriostatic
Is sulfamethoxazole bacteriostatic or bacteriocidal?
Bacteriostatic (when used alone)
Is linezolid bacteriostatic or bacteriocidal?
Bacteriostatic
Are beta-lactams bacteriostatic or bacteriocidal?
Bacteriocidal (except against Enterococcus spp. - synergy required for serious infections)
Are aminoglycosides bacteriostatic or bacteriocidal?
Bacteriocidal
Are fluoroquinolones bacteriostatic or bacteriocidal?
Bacteriocidal
Is vancomycin bacteriostatic or bacteriocidal?
Bacteriocidal (except against Enterococcus spp. - synergy required for serious infections)
Is daptomycin bacteriostatic or bacteriocidal?
Bacteriocidal
is metronidazole bacteriostatic or bacteriocidal?
Bacteriocidal (against anaerobes)
Is sulfamethoxazole-trimethoprim bacteriostatic or bacteriocidal?
Bacteriocidal
What are the bacteriostatic antimicrobials?
Macrolides Tetracyclines Clindamycin Sulfamethoxazole (when used alone) Linezolid
What are the bacteriocidal antimicrobials
Beta-lactams (Exception: Enterococcus spp.)
Aminoglycosides
Fluoroquinolones
Vancomycin (Exception: Enterococcus spp.)
Daptomycin
Metronidazole (against anaerobes)
Sulfamethoxazole-trimethoprim
What is the pharmacodynamic profile for beta-lactams:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Time-dependent
What is the pharmacodynamic profile for erythromycin:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Time-dependent
What is the pharmacodynamic profile for flucytosine:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Time-dependent
What is the pharmacodynamic profile for aminoglycoside:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Concentration-dependent
What is the pharmacodynamic profile for fluoroquinolones:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Concentration-dependent/mixed killing
What is the pharmacodynamic profile for metronidazole:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Concentration-dependent
What is the pharmacodynamic profile for daptomycin:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Concentration-dependent
What is the pharmacodynamic profile for amphotericin B:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Concentration-dependent
What is the pharmacodynamic profile for echinocandins:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Concentration-dependent
What is the pharmacodynamic profile for clarithromycin:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for azithromycin:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for clindamycin:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for tetracyclines:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for linezolid:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for vancomycin:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) dose-dependent (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for tigecycline:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for colistin:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What is the pharmacodynamic profile for azoles:
a) time-dependent (T > MIC)
b) concentration-dependent (Cmax:MIC)
c) mixed killing (AUC24:MIC)?
Mixed
What are the time-dependent killing (T > MIC) antimicrobials?
Penicillin Cephalosporins Aztreonam Erythromycin Flucytosine
What are the concentration-dependent killing (Cmax:MIC) antimicrobials?
Aminoglycosides Fluoroquinolones Metronidazole (against anaerobes) Daptomycin Amphotericin B Echinocandins
What are the mixed-killing (AUC24:MIC) killing antimicrobials?
Fluoroquinolones Clarithromycin Azithromycin Clindamycin Tetracycline Linezolid Vancomycin Tigecycline Colistin Azoles
What is the post-antimicrobial effect?
An effect of antimicrobials where growth is still inhibited even after the concentration of the antibiotic falls below the MIC.
Which antibiotics have a post-antimicrobial effect?
1) Most antibiotics against Gram positive organisms
2) Aminoglycosides against Gram negative organisms
3) Fluoroquinolones against Gram negative organisms
4) Carbapenems against Pseudomonas aeruginosa
What are the rates of cross-reactivity between penicillin-allergic patients and cephalosporins?
1)
What tissues/areas are well penetrated by antibiotics?
Urine, kidneys, other soft tissues
What tissues/areas are poorly penetrated by antibiotics?
1) Eye (privileged site)
2) Prostate (fluoroquinolones and macrolides are best)
3) Abscesses
4) Endocarditis vegetations (biofilms are hard to penetrate)
Why is immune status of the patient important?
1) Provides clues as to the types of pathogens that may be present
2) Can make use favour a bactericidal agent vs. a bacteriostatic agent
What are the characteristics of time-dependent killing (T > MIC)?
Killing is dependent on the time the antibiotic concentrations are above the organisms MIC.
What are the characteristics of concentration-dependent killing (Cmax:MIC)?
Killing is dependent on how high the drug concentration is above the MIC.
What are the characteristics of mixed killing (AUC24:MIC)?
Killing is dependent both on the time of drug exposure above MIC and how high the drug concentration is above MIC.
What are six causes of treatment failure?
1) Incorrect diagnosis (wrong organisms being treated or wrong antibiotic selected)
2) Inadequate exposure of the organism to the antibiotic at the site of infection
3) Acquisition of resistant organisms while on treatment
4) Host factors (impaired immune system, poor source control, foreign materials for biofilms to form on)
5) Drug interactions
6) Non-adherence