PKPD of Antimicrobial Agents

Question 1

What are the three pkpd indices of antimicrobial agents?

Answer 1

%T > MIC
Cmax: MIC
AUC : MIC

Question 2

What agents have a %T > MIC pkpd indice?

Answer 2

COMP-C

C: Cephalosporins
O: Oxazolidiones
M: Macrolides
P: Penicillins
C: Carbapenems

We should adjust dose for these drugs by increasing infusion times, using continuous infusions, decreasing dose intervals and increasing doses.

Question 3

What Agents have a Cmax: MIC pkpd indice?

Answer 3

Aminoglycosides and Quinolones

To optimize dosing–> use extended interval dosing and maximize safe dose.

Question 4

What agents follow AUC:MIC pkpd indice?

Answer 4

VAT

V: Vancomycin
A: Azithromycin
T: Tetracycline

Question 5

Hydrophilic Antimicrobials

Answer 5

LAG-B

L: Lipopeptides
A: Amioglycosides
G: Glycopeptides
B: Beta-Lactams

Question 6

Which antimicrobials are renally cleared?

Answer 6

Hydrophillic

Question 7

Where do hydrophillic and hydrophobic antimicrobials distribute?

Answer 7

Hydrophillic = ECF
Hydrophobic = ICF

Question 8

Which antimicrobials should have dose adjustments in sepsis?

Answer 8

Hydrophilic

Question 9

When would you adjust the dose of a hydrophobic antimicrobial agent?

Answer 9

Liver Failure

Question 10

Which Antibiotics do not need renal dose adjustments:

Answer 10

CLEAN Dox MeT QD

C: Clindamycin and Ceftriaxone
L: Linezolid
E: Erythromycin
A: Azithromycin
N: Nafcillin

D: Doxycycline

M: Moxifloxacin and Metronidazole
T: Tigecycline

Q: Quinpristine
D: Dalfupristin

Question 11

Rapid Resistors

Answer 11

QCR

Q: Quinolones
C: Clindamycin
R: Rifampin

Question 12

Fluoroquinolone AUC Goals

Answer 12

AUC:MIC 125-250

Do not let AUC:MIC <100 —> Resistance concerns

Question 13

Vancomycin AUC: MIC Ratio

Answer 13

> 400 mg*hr/L

Question 14

Old-School Trough Goals for vancomycin

Answer 14

10-15/15-20

Question 15

Vancomycin dose

Answer 15

15 mg/kg/Q12 hr –> Round to the nearest 250 mg dose.

Question 16

Explain how the following will effect the concentration of a hydrophilic antimicrobial agent:

1.) Decreased Cardiac Output
2.) Increased Capillary Leakiness
3) AKI
4) CKD

Answer 16

1. Reduced CL –> Higher Concentrations
2. increased Vd —> Lower Concentrations
3. AKI–> Increased or Decreased CL
4. Reduced CL–> Higher Concentrations.

Question 17

Where do most infections in healthy people typically occur?

Answer 17

Highly perfused tissues.

Question 18

In gram negative bacteria, the ____ serves as a significant barrier to a number of antibiotics.

Answer 18

Outer membrane.

Question 19

Which anaerobes are typically more pathogenic?

Answer 19

Gram Negative.

Question 20

______: In every population of bacteria there are some which have the resistant gene. Therefore, when antibiotics are given, we are positively selecting for resistant populations which will grow when sensitive populations are killed off.

Answer 20

Heteroresistance.