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Flashcards in Antibiotic Therapy Deck (84)
0

Vancomycin is a "BLANK"

Glycopeptide

1

Mechanism of action of glycopeptides

Inhibition of bacterial cell wall synthesis. Work at an earlier stage than do beta-lactams.

2

Daptomycin is a "BLANK"

Lipopeptide

3

Mechanism of action of Lipopeptides

Disruption of cell wall.

- Calcium dependent
- Depolarizes cell membrane
- Disrupts RNA, DNA, protein synthesis --> cell death

4

In general, Glycopeptides/Lipopeptides are active against:

Gram +ve organisms, including beta-lactam resistant organisms (i.e. MRSA)

5

Are Glycopeptides/Lipopeptides bacteriostatic or bactericidal?

Bactericidal

6

This Glycopeptide is slowly cidal, and when given PO is not systemically absorbed

Vancomycin

7

Lung surfactant inactivates "BLANK"; therefore, this agent should not be used to treat pneumonia!

Daptomycin

8

Spectrum and indications for Vancomycin IV

Spectrum: Gram +ve (Enterococci, penicillin resistant Streptococci, MRSA, CNS

Indications: Bacteremia, pneumonia, endocarditis, bone/joint, SSTI, surgical prophylaxis

9

Spectrum and indications for Vancomycin PO

Spectrum: C. difficile

Indications: C. difficile infection

10

Spectrum and indications for Daptomycin IV

Spectrum: Gram +ve (Enterococci, penicillin-resistant Streptococci, MRSA, CNS, and VRE)

Indications: Bacteremia, endocarditis, bone/joint, SSTI

11

Gentamycin and Tobramycin are both "BLANKS"

Aminoglycosides

12

Mechanism of action for Aminoglycosides

Inhibit protein synthesis by binding the 30S ribosomal subunit

13

Are Aminoglycosides bacteriostatic or bactericidal?

Bactericidal

14

Aminoglycosides are renally excretable and may cause the following toxicities (2)

1. Nephrotoxicity
2. Ototoxicity

15

Gentamicin and beta-lactams act synergistically against what?

Enterococci

16

Spectrum and indications for Gentamicin IV

Spectrum: Gram -ve, Pseudomonas, synergy vs Streptococci and Enterococci with beta-lactam or vancomycin

Indications: Drug resistant UTI, combination therapy for Gram -ve sepsis, synergy for Gram +ve bacteremia and endocarditis

17

Spectrum and indications for Tobramycin IV

Spectrum: Gram -ve, Pseudomonas (better than gentamicin)

Indications: Drug resistant UTI, combo therapy for serious Pseudomonas infections

18

Azithromycin is a "BLANK"

Macrolide

19

Mechanism of action for Macrolides

Inhibit protein synthesis by binding the 23S rRNA in the 50S ribosomal subunit

20

Macrolides are active against intracellular organisms, true or false?

TRUE

21

Are Macrolides bacteriostatic or bactericidal?

Bacteriostatic

22

Does Azithromycin have a long or short half life?

LONG

23

Spectrum and indications for Azithromycin IV/PO

Spectrum: Mycoplasma, Chlamydophila, Legionella, M. catarrhalis, Chlamydia trachomatis, N. gonorrheae, MAC

Indications: Combo therapy for MAC Tx, MAC prophylaxis in HIV pt's, 2nd line for STI's, combo with beta-lactam for CAP

24

Why is Azithromycin the preferred macrolide over erythromycin and clarithromycin? (5)

1. Broader spectrum
2. Fewer drug interactions
3. Once daily dosing
4. Tolerability
5. IV option

25

Clindamycin is a "BLANK"

Lincosamide

26

What is the mechanism of action of Clindamycin?

Inhibits proteins synthesis by binding to the 50S ribosomal subunit

27

What is the bioavailability of Clindamycin?

Excellent

28

Is Clindamycin bacteriostatic or bactericidal?

Bacteriostatic

29

Clindamycin inhibits toxin production from what?

Group A Streptococcus

30

Clindamycin is used in combination with what other antibiotic to treat necrotizing faciitis?

Penicillin

31

Clindamycin is high risk for what?

C. difficile

32

Spectrum and indications for Clindamycin PO/IV

Spectrum: Streptococci, S. aureus, MRSA (if susceptible), anaerobes

Indications: SSTI, bone/joint, abscesses, alternative for dental infections, polymicrobial infections in combo with Gram -ve agent, combo vs necrotizing faciitis

33

Doxycycline and Tigecycline fall under what family of antibiotics?

Tetracyclines/Glycylcyclines

34

What is the mechanism of action of Tetracyclines/Glycylcyclines?

Inhibits protein synthesis by binding the 30S and 50S ribosomal subunits

35

Tetracyclines/Glycylcyclines are bacteriostatic, true or false?

TRUE

36

Tetracyclines and Glycylcyclines are active against intracellular pathogens, true or false?

TRUE

37

Spectrum and indications for Doxycycline PO

Spectrum: Mycoplasma, Chlamydophila, Legionella, Chlamydia trachomatis, S. pneumoniae, Haemophilus, Moraxella, S. aureus (including MRSA)

Indications: COPD, CAP, Chlamydial STIs, purulent cellulitis (suspected MRSA)

38

Spectrum and indications for Tigecycline IV

Spectrum: Broad spectrum, Gram +ve (E. faecalis, MRSA), Gram -ve, anaerobes

Indications: Last line option of polymicrobial, multidrug resistant organisms if susceptibility confirmed

39

3 problems with Tetracycline PO

1. Requires QID dosing on an empty stomach
2. Poorly tolerated
3. Narrower spectrum than Doxycycline

40

Ciprofloxacin and Levofloxacin are both "BLANKS"

Fluoroquinolones

41

What is the mechanism of action of Fluoroquinolones?

Inhibition of DNA gyrase and topoisomerase

42

Bioavailability of Fluoroquinolones

EXCELLENT

43

Are Fluoroquinolones bacteriostatic or bactericidal?

Bactericidal

44

What 2 Fluoroquinolones are active against intracellular pathogens?

1. Levofloxacin
2. Moxifloxacin

45

Fluoroquinolones are high risk for C. difficile, true or false?

TRUE

46

Widespread use of Fluoroquinolones is leading to the development of resistance by which type of bacteria?

Gram -ve

47

Spectrum and indications for Ciprofloxacin IV/PO

Spectrum: Gram -ve, Pseudomonas

Indications: Not usually 1st line due to increasing Gram -ve resistance, UTI, in combo with metronidazole or clindamycin for polymicrobial infections

48

Spectrum and indications for Levofloxacin IV/PO

Spectrum: Streptococci, Mycoplasma, Chlamydophila, Legionella, Gram -ve

Indications: Not 1st line, reserve for suspected drug-resistant respiratory infections or allergy to 1st line agents.

49

Moxifloxacin is a respiratory fluoroquinolone, what is the risk of C. difficile with this drug?

High

50

Which Fluoroquinolone is active against multidrug resistant TB?

Moxifloxacin

51

Which Fluoroquinolone has no Pseudomonas activity and does not get to therapeutic concentration in the urinary tract?

Moxifloxacin

52

TMP-SMX and Nitrofurantoin are considered to be part of what family of antibiotics?

Anti-folates

53

Mechanism of action of Trimethoprim-sulfamethoxazole

Together they inhibit purine synthesis, preventing DNA synthesis

54

What is the mechanism of action of nitrofurantoin?

It is reduced inside the cell to produce reactive intermediates that cause cellular damage. There is minimal resistance due to complex mechanism.

55

TMP/SMX acts as a "BLANK" agent

Bacteriostatic

56

The bioavailability of TMP/SMX is...

EXCELLENT (PO)

57

Nitrofurantoin is (bacteriostatic/bactericidal), and only achieves therapeutic concentrations in (urine/blood)

Bactericidal, Urine

58

Nitrofurantoin is effective for cystitis, but not "BLANK"

Pyelonephritis

59

Spectrum and indications for Trimethoprim/Sulfamethoxazole IV/PO

Spectrum: Gram -ve, S. aureus (MRSA), S. pneumoniae, Nocardia, Pneumocystis jiroveci

Indications: UTI (not first line), purulent cellulitis (MRSA), Nocardia infections, PCP Tx and prophylaxis

60

Spectrum and indications for Nitrofurantoin PO

Spectrum: E. coli, Klebsiella, E. faecalis

Indications: 1st line for cystitis

61

Metronidazole is in which family of antibiotics?

Nitroimidazoles

62

What is the mechanism of action for Metronidazole?

It inhibits DNA synthesis

63

What is the bioavailability of Metronidazole?

EXCELLENT - also has excellent penetration of the CNS

64

What should you avoid when taking Metronidazole?

Alcohol (disulfiram reaction)

65

Spectrum and indications for Metronidazole PO/IV

Spectrum: Anaerobes (including C. difficile), Protozoa (i.e. Giardia)

Indications: C. difficile, used in combo for polymicrobial infections/abscesses, trichomoniasis

66

Linezolid belong to this class of antibiotics...

Oxazolidinones

67

Mechanism of action for Linezolid

Inhibits protein synthesis by binding to 23S rRNA in 50S ribosomal subunit - prevents the formation of 70S ribosome.

68

Bioavailability of Linezolid...

EXCELLENT

69

Linezolid is bacteriostatic/bactericidal...

Bacteriostatic

70

What is there a risk of with prolonged use (> 2 weeks) of Linezolid?

Cytopenias

71

Linezolid has activity against beta-lactam and vancomycin resistant organisms, true or false?

TRUE

72

Spectrum and indications for Linezolid PO/IV

Spectrum: Streptococci, Enterococci, Staphylococci, anaerobes

Indications: Resistance, allergy or failure with vancomycin therapy

73

Which 4 drugs were presented as anti-tuberculosis drugs?

1. Rifampin
2. Isoniazid
3. Pyrazinamide
4. Ethambutol

74

The 4 drug combo used for TB is bacteriostatic/bactericidal?

Bactericidal

75

Anti-tuberculosis drugs are poorly absorbed, true or false?

FALSE

76

Rifampin is a potent inhibitor/inducer of CYP 3A4?

Inducer

77

What type of toxicity should you monitor for when giving someone the empirical 4 drug combo for TB?

Hepatotoxicity

78

Indications for Rifampin

Penetrates Staph biofilms, TB, MAC, latent TB Tx

79

Indications for Isoniazid

TB and latent TB Tx

80

Indications for Pyrazinamide

TB

81

Indications for Ethambutol

TB, MAC

82

How much can you save by switching to Geico?

15% or more

83

Which antibiotics are effective against MRSA?

1. Vancomycin IV (PO is not systemically absorbed)
2. Daptomycin IV
3. Clindamycin PO/IV (if susceptible..) - High risk of C. difficile!
4. Doxycycline PO
5. Tigecycline IV (last line option)
6. TMP/SMX IV/PO
7. Linezolid PO/IV (expensive, cytopenias with prolonged Tx)