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Pharmacology Fall 2016 > 50S Inhibitors > Flashcards

Flashcards in 50S Inhibitors Deck (43)
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1
Q

What are the 3 clinically relevant Lincosamides?

A
  1. Lincomycin
  2. Clindamycin
  3. Pirlimycin
2
Q

What is the MOA of Lincosamides?

A

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

3
Q

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

A

Reversible –> Bacteriostatic

4
Q

What is the spectrum of the Lincosamides?

A
  1. Gram (+) aerobes: Staph & Strep
  2. Gram (+) anaerobes
  3. Gram (-) aerobes: Campylobacter & Brachyspira
  4. Gram (-) anaerobes: Bacteroides & Fusobacterium
  5. Eukaryotes: Toxoplasma (Clindamycin)
5
Q

Which is better with anaerobes, Clindamycin or Lincomycin?

A

Clindamycin

6
Q

Which is better with Staphylococcus, Clindamycin or Lincomycin?

A

Clindamycin

7
Q

What is Pirlimycin used against?

A

Bovine mastitis

8
Q

How is Pirlimycin administered?

A

Intramammary

9
Q

When is Pirlimycin NOT to be used vs. mastitis?

A

NOT to be used vs. gram (-) bacilli

10
Q

How do bacteria mount resistance to Lincosamides?

A

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

11
Q

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

A
  1. Phenicols
  2. Macrolides
  3. Streptogramins
12
Q

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

A

Pseudomembranous colitis

13
Q

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

A

Metronidazole

14
Q

What is virginiamycin a mixture of?

A
  1. Virginamycin M (Group A)

2. Virginamycin S (Group B)

15
Q

What is synercid a mixture of?

A
  1. Dalfopristin (Group A)

2. Quinupristin (Group B)

16
Q

What is the MOA for the Streptogramins?

A

50S inhibitors

17
Q

Are Streptogramins bacteriostatic or bactericidal?

A

Bactericidal (2 drugs combined)

18
Q

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

A
  1. Macrolides

2. Lincosamides

19
Q

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

A

No

20
Q

Are Streptogramins water or fat soluble?

A

Water soluble

21
Q

Are Streptogramins orally bioavailable?

A

No - poor oral bioavailability

22
Q

How do Streptogramins have to be administered?

A

Injected

23
Q

What is the spectrum of the Streptogramins?

A

Gram (+) aerobes and anaerobes

24
Q

What are the 2 clinically relevant phenols?

A
  1. Chloramphenicol

2. Florfenicol

25
Q

What is the MOA of the phenols?

A

50S inhibitors

26
Q

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

A

Very broad, including Rickettsia

27
Q

Which 2 organisms are the Phenols resistant to?

A
  1. Nocardia

2. Mycoplasma

28
Q

How do bacteria mount resistance to the Phenols?

A

The bacteria modify the drug via acetylation

29
Q

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

A

Chloramphenicol

30
Q

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

A

Florfenicol

31
Q

Resistance to which is less likely, Chloramphenicol or Florfenicol?

A

Florfenicol

32
Q

Which drug is the “broadest”, Chloramphenicol or Florfenicol?

A

Florfenicol

33
Q

Why are the Phenols good against meningitis?

A

60% of the plasma concentration reaches the CSF

34
Q

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

A

Chloramphenicol

35
Q

How do the Phenols cause aplastic anemia?

A

Inhibit mitochondrial protein synthesis in erythropoeitic cells

36
Q

What is Florfenicol used against in the cow?

A

Bovine respiratory disease

37
Q

What is Florfenicol + NSAID?

A

Flunixin

38
Q

What is the MOA of the pleuromutilins?

A

50S inhibitors

39
Q

What are the 2 clinically relevant Pleuromutilins?

A
  1. Tiamutilin

2. Valnemulin

40
Q

What is the spectrum of the Pleuromutilins?

A

Gram (+)

41
Q

What is the MOA of the oxazolidinones?

A

50S inhibitors

42
Q

What is the spectrum of the Oxazolidinones?

A

Gram (+) aerobes and anaerobes

43
Q

What is 1 clinically relevant oxazolidinone?

A

Linezolid