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Flashcards in Antimicrobials Deck (68):
1

What had biggest effect on human life expectancy?
A. Public health measures, sanitation, and immunization
B. Antimicrobials

A. Public health measures

2

% of death worldwide due to infectious disease?

10%

3

How are antibacterials classified?

By MOA

4

MIC definition?

Lowest concentration of drug that inhibits visible growth

5

MBC definition?

Lowest concentration of drug that kills bacteria

6

Define bacteriostatic in terms of MBC and MIC

MBC >> MIC

7

Define bactericidal in terms of MBC and MIC

MBC roughly equals MIC

8

The lower the MBC/MIC of an organism/drug combo, the ____ the organism.

more susceptible

9

Methods for determining microbial susceptibility/resistance?

Culture based (disk diffusion and E-test) or molecular detection of resistance mutations (i.e. PCR)

10

What is a hospital antibiogram?

Summary of antibiotic susceptibilities in your own site to track resistance trends

11

Pharmacodynamics is...

the biological effects of the drug on the body (i.e. time course and intensity of therapeutic and adverse effects)

12

Pharmacokinetics is...

the body's effect on the drug (i.e. time course of absorption, distribution, metabolism, and excretion)

13

Cmax is?

Peak concentration of drug in body

14

AUC is?

Area under the curve

15

Time dependent killing goal?

Maximize time above the MIC; you want serum [drug] above MIC for at least 50% of dosing interval

16

Beta lactam MOA?

bind PBP and inhibit peptidoglycan synthesis

17

Name the 5 beta lactam subclasses

penicillins, carbapenems, monobactams, clavulanic acid, cephalosporins

18

Glycopeptides MOA?

inhibit transglycosylase activity in peptidoglycan synthesis

19

Function of PBPs?

make peptidoglycan

20

PBPs must have ____ function, and may also have ____ function.

peptidyltransferase; transglycosylase

21

Penicillin resembles...

D-Ala D-Ala moiety

22

Concentration-dependent killing goal?

Maximize Cmax and therefore AUC

23

Drugs with TDK MOA?

Penicillins, Cephalosporins, Macrolides, Clindamycin

24

Drugs with CDK MOA?

Fluoroquinolones, Aminoglycosides

25

Post antibiotic effect is...

time it takes bacteria to return to log phase growth after removal of abx

26

Bacteria with longer PAEs require need ___ frequencies of dosing.

lower

27

Which generally needs longer PAE? CDK or TDK?

CDK

28

Which generally needs longer PAE? Gram + or -?

Gram +

29

What are the three main antibiotic resistance mechanisms?

Enzymatically inactivate drug, alter drug target, alter drug exposure

30

What does beta-lactamase do?

Enzymatically inactivate beta-lactams

31

What does clavulanic acid do?

Inhibits beta-lactamase, overcome abx resistance

32

2 beta-lactamases to know?

ESBL (extended spectrum beta lactamases) and Metal-dependent/New Delhi

33

What is the "nuclear option" for beta-lactam resistance?

PBP mutation that alters affinity for beta-lactams, but still retain transpeptidase activity

34

Prioritize choosing abx with ____ fitness cost for resistance

higher

35

Gram ___ bacteria alter their membrane permeability to pump out abx

negative

36

2 ways to alter drug exposure?

decrease membrane permeability; increase efflux of drug to shoot out of cell

37

Main abx resistance mechanism for vancomycin?

Alter D-Ala D-Ala slightly with lac so that vancomycin cannot bind precursor.

38

Lipopeptides MOA?

disrupt cell membrane of G+ by binding phosphatidyl-glycerol forming pores

39

Why are lipopeptides specific?

Phosphatidyl-glycerol is abundant in bac cells but not human cells

40

What part of body should lipopeptides not be used to treat?

Lungs (surfactant)

41

Main lipopeptide to know?

Daptomycin

42

Main class of folate synthesis inhibitors?

Sulfonamides

43

Main sulfonamide to know?

Sulfamethoxazole

44

Are sulfonamides bacteriostatic or bactericidal?

Bacteriostatic, combine with trimethoprim to make bactericidal

45

Are fluoroquinolones bacteriostatic or bactericidal?

Bactericidal

46

Fluoroquinolone resistance is usually via ____ and/or ___

altering the drug target (mutations in topoisomerase genes); altering the drug exposure by decreasing uptake

47

Rifamycins MOA?

inhibit mRNA synthesis by binding DNA dep RNA Pol

48

Rifamycins bacteriostatic or bactericidal?

Either! Depends on concentration

49

Rifamycin to know?

Rifampin

50

Rifamycin is rarely used alone because it quickly develops abx resistance by ____

mutations in RNA polymerase gene (altered drug target)

51

2 main classes of drugs that damage DNA?

fluoroquinolones and nitroimidazoles

52

Main nitroimidazole to know?

metronidazole

53

Nitroimidazole MOA?

forms free radicals that damage DNA

54

Which class of abx is a prodrug? What does this mean?

nitroimidazoles - must be activated by microbial enzymes

55

Most likely cause of abx resistance in nitroimidazoles?

mutations in microbial enzymes that convert prodrug to active compound

56

Name all the classes of 30S ribosome antibiotics.

tetracyclines, aminoglycosides

57

Name the 2 important tetracyclines to know.

Tetracycline, doxycycline

58

Name the 2 important aminoglycosides to know.

gentamycin, streptomycin

59

Name the 2 classes of abx used for anaerobic microbes exclusively. Which one is bacteriostatic and which one is bactericidal?

Lincosamides, nitroimidazoles; lincosamides = static, nitroimidazoles = cidal

60

Aminoglycosides should not be used in what part of the body and why?

the GI tract; will be ineffective because anaerobes are intrinsically resistant

61

Tetracycline is bacteriostatic or bactericidal?

Bacteriostatic

62

Bacteriostatic drugs + bactericidal drugs = ?

Antagonistic effect

63

5 classes of abx that bind 50S subunit?

oxazolidenones, streptomycins, lincosamides, macrolides, chloramphenicol

64

Clindamycin falls under what class of antibiotic?

Lincosamide

65

2 main types of macrolides to know?

erythromycin, azithromycin

66

MLSb resistance is associated with which abx? Why does it happen?

macrolides, lincosamides, and streptogramins; similar MOA

67

What does the D test detect?

inducible clindamycin resistance

68

Main oxazolidinone to know?

linezolid