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Pharmacology Fall 2016 > 50S Inhibitors > Flashcards

Flashcards in 50S Inhibitors Deck (43):
1

What are the 3 clinically relevant Lincosamides?

1. Lincomycin

2. Clindamycin

3. Pirlimycin

2

What is the MOA of Lincosamides?

Bind to the 50S subunit of the ribosome and prevent exiting of the growing peptide chain.

3

Is the MOA of Lincosamides reversible or non-reversible? Bacteriostatic or bactericidal?

Reversible --> Bacteriostatic

4

What is the spectrum of the Lincosamides?

1. Gram (+) aerobes: Staph & Strep

2. Gram (+) anaerobes

3. Gram (-) aerobes: Campylobacter & Brachyspira

4. Gram (-) anaerobes: Bacteroides & Fusobacterium

5. Eukaryotes: Toxoplasma (Clindamycin)

5

Which is better with anaerobes, Clindamycin or Lincomycin?

Clindamycin

6

Which is better with Staphylococcus, Clindamycin or Lincomycin?

Clindamycin

7

What is Pirlimycin used against?

Bovine mastitis

8

How is Pirlimycin administered?

Intramammary

9

When is Pirlimycin NOT to be used vs. mastitis?

NOT to be used vs. gram (-) bacilli

10

How do bacteria mount resistance to Lincosamides?

Via methylation of the ribosome, so the ribosome cannot produce proteins.

11

The methylation process through which Lincosamides mount resistance to bacteria confers resistance to what 3 drug classes?

1. Phenicols

2. Macrolides

3. Streptogramins

12

Clindamycin causes ____ ____ due to inhibition of good intestinal microbes.

Pseudomembranous colitis

13

Which drug can be given in conjunction with Clindamycin to prevent pseudomembranous colitis?

Metronidazole

14

What is virginiamycin a mixture of?

1. Virginamycin M (Group A)

2. Virginamycin S (Group B)

15

What is synercid a mixture of?

1. Dalfopristin (Group A)

2. Quinupristin (Group B)

16

What is the MOA for the Streptogramins?

50S inhibitors

17

Are Streptogramins bacteriostatic or bactericidal?

Bactericidal (2 drugs combined)

18

Group B Streptogramins share cross-resistance with which 2 antimicrobial classes?

1. Macrolides

2. Lincosamides

19

Do Group A Streptogramins share cross-resistance with Group B?

No

20

Are Streptogramins water or fat soluble?

Water soluble

21

Are Streptogramins orally bioavailable?

No - poor oral bioavailability

22

How do Streptogramins have to be administered?

Injected

23

What is the spectrum of the Streptogramins?

Gram (+) aerobes and anaerobes

24

What are the 2 clinically relevant phenols?

1. Chloramphenicol

2. Florfenicol

25

What is the MOA of the phenols?

50S inhibitors

26

What is the spectrum of the Phenols (chloramphenicol and florfenicl)?

Very broad, including Rickettsia

27

Which 2 organisms are the Phenols resistant to?

1. Nocardia

2. Mycoplasma

28

How do bacteria mount resistance to the Phenols?

The bacteria modify the drug via acetylation

29

Which of the following has 2 targets for resistance: Chloramphenicol or Florfenicol?

Chloramphenicol

30

Which of the following only has 1 target for resistance: Chloramphenicol or Florfenicol?

Florfenicol

31

Resistance to which is less likely, Chloramphenicol or Florfenicol?

Florfenicol

32

Which drug is the "broadest", Chloramphenicol or Florfenicol?

Florfenicol

33

Why are the Phenols good against meningitis?

60% of the plasma concentration reaches the CSF

34

Which is more likely to cause aplastic anemia in a human, Chloramphenicol or Florfenicol?

Chloramphenicol

35

How do the Phenols cause aplastic anemia?

Inhibit mitochondrial protein synthesis in erythropoeitic cells

36

What is Florfenicol used against in the cow?

Bovine respiratory disease

37

What is Florfenicol + NSAID?

Flunixin

38

What is the MOA of the pleuromutilins?

50S inhibitors

39

What are the 2 clinically relevant Pleuromutilins?

1. Tiamutilin

2. Valnemulin

40

What is the spectrum of the Pleuromutilins?

Gram (+)

41

What is the MOA of the oxazolidinones?

50S inhibitors

42

What is the spectrum of the Oxazolidinones?

Gram (+) aerobes and anaerobes

43

What is 1 clinically relevant oxazolidinone?

Linezolid