Abx II (lecture) Flashcards

1
Q

What is the MoA of linezolid?

A

Bind to 50s of bacterial tRNA, preventing 70s formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the spectrum of Linezolid?

A

Broad G + specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the indication of Linezolid use?

A

Multi drug resistant strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the mechanism of linezolid resistance?

A

Mutation of the 50s subunit preventing linezolid binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What consideration is related to linezolid use with andrenergics, serotonergics and high tyramine intake (wine, cheese, and picked meats)?

A

Enhanced effects may result

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are two drugs are considered tetracyclines (other than tetracycline of course)?

A

Doxycycline and Minocycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the mechanism of tetracyclines?

A

Bind the 30s subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the spectrum of tetracyclines?

A

Broad, mostly G +

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What Rx is indicated in Lyme disease?

A

Doxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does milk influence tetracycline uptake?

A

Cations hinder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are two absolute contraindications of tetracycline use?

A

Pregnancy and under 8 y.o.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the three mechanisms of tetracycline resistance?

A

Efflux pump
Tet-O: Ribosome protecting proteins
Enzymatic inactivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the MoA of tigecycline?

A

Bind the 30s subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the spectrum of tigecycline?

A

Broad G + and G - anaerobe and aerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What “-cycline” is safe for use in renal failure and mild hepatic failure?

A

Tigecycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the MoA of tigecycline (2) resistance?

A

TetX inactivation

AcrAB efflux

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Streptomycin, gentamicin, neomycin, kanamycin and spectinomycin are all examples of what class of Abx?

A

Aminoglycosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the MoA of aminoglycosides?

A

Bind 30s subunit and initiate premature termination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the spectrum of aminoglycosides?

A

Broad G - aerobics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 4 main adverse effects of aminoglycosides?

A

Nephrotoxic
Ototoxic
Curare-like muscular blockade
Nerve dysfunction

21
Q

With which Abx group are aminoglycosides synergistic?

A

B-lactams

22
Q

What are the 2 mechanisms of amino glycoside resistance?

A

Enzyme inactivation

Decreased permeability to inner membrane

23
Q

What is the MoA of chloramphenicol?

A

Prevent transferase on the 50s subunit

24
Q

What is the spectrum of chloramphenicol?

A

Broad G -, most anaerobes

25
Q

How is chloramphenicol metabolized?

A

Hepatic inactivation and renal excretion

26
Q

What are the clinical uses of chloramphenicol?

A

Limited: typhoid, bacterial meningitis, anaerobe infections, rickettsial

27
Q

What is the MoA of chloramphenicol toxicity?

A

Mitochondrial 70s ribosome inhibition

28
Q

What is the concern with administration of chloramphenicol to neonates?

A

Gray baby syndrome (40% fatal)

29
Q

What is the mechanism of resistance with chloramphenicol and in what bacteria (2 genera) is this a primary concern?

A

Decrease membrane permeability
Enzyme inactivation
Salmonella and Shigella

30
Q

What drug classification do erythromycin, clarithromycin, and azithromycin fall under?

A

Macrolides

31
Q

What is the spectrum of macrolides?

A

G +&raquo_space; G -

32
Q

What is the DoC of sinusitis and mild pneumonia?

A

Azithromycin

33
Q

How are microlides excreted?

A

Mainly biliary

34
Q

What macrolide is contraindicated in pregnancy, which is used?

A

Erythromycin is contraindicated

Azithromycin is used

35
Q

What are the mechanisms (4) of resistance to macrolides?

A

ATP-dependent efflux
MLSB decreased binding
esterase hydrolysis
Decreased RNA binding

36
Q

What drug is indicated for B. fragilis, Peptococcus, and Clostridium?

A

Clindamycin

37
Q

What are the routes of clindamycin administration?

A

All: oral, topical, IM or IV (fro serious infections)

38
Q

What are the 3 sites of clindamycin adverse effects?

A
neuromuscular transmission inhibition
GI: 
   - Life threatening pseudomembranous enterocolitis
   - C. difficile overgrowth
   - Diarrhea
Skin: Rash (esp with HIV and AIDS pts.)
39
Q

What is the benefit of clinamycin over macrolides?

A

No ATP dependent efflux

40
Q

What class of Abx ends in “-pristin”?

A

Streptogramins

41
Q

What is the DoC for vancomycin-resistant F. faecium and S. aureus and Strep pyogenes skin infections?

A

Streptogramins

42
Q

How are quinupristin and dalfopristin synergistic?

A

dalf enhances quin binding, which inhibits translocation

43
Q

What is a special consideration of streptogramin administration?

A

5% dextrose only over 1 hr

44
Q

How do streptogramins effect liver metabolism?

A

CYP3A4 inhibitor

45
Q

What are the 3 mechanisms of streptogramin resistance?

A

ATP-dependent efflux
MLSB mutations fo rRNA
Lactonase and acetyl transferase

46
Q

What is the first line drug for UTI?

A

Nitrofurantoin

47
Q

What may nitrofurantoin induce in G6PD?

A

Hemolytic anemia

48
Q

What is a special consideration of nitrofurantoin used during pregnancy?

A

Safe during first 6 months

49
Q

Can nitrofurantoin be used during kidney failure?

A

NO