EXAM #4: ANTIBIOTICS III Flashcards Preview

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Flashcards in EXAM #4: ANTIBIOTICS III Deck (60)
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1
Q

What class of antibiotic is Clindamycin?

A

Protein synthesis inhibitor

2
Q

What is the spectrum of specificity of Clindamycin?

A

Narrow–commonly used to treat strep and staph soft tissue infections

3
Q

What is the MOA of Clindamycin?

A
  • Blocks the 50S subunit
  • Step 1 (A site)
  • Also blocks translocation of the amino acid chain to the P site
4
Q

What are the key adverse effects associated with Clindamycin?

A

GI disturbances esp. C. DIFF

5
Q

What class of antibiotic is Chloramphenicol?

A

Protein synthesis inhibitor

6
Q

What is the MOA of Chloramphenicol?

A
  • Binds the 50S subunit

- Prevents peptide bond formation

7
Q

What are the key adverse effects seen with Chloramphenicol?

A

1) Suppression of RBC production

2) Gray Baby Syndrome

8
Q

What is Gray Baby Syndrome?

A
  • Serious side effect of IV chloramphenicol administration in newborn
  • Infants have immature UGT
  • UGT is needed to metabolize the drug–concentrations become toxic
9
Q

What is Cloramphenicol typically used to treat?

A

Serious infections such as Typhus and Rocky Mountain Spotted Fever

10
Q

What are the three drugs used to treat “resistant” organisms?

A

Vancomycin
Linezolid
Daptomycin

11
Q

What class of drug is Linezolid?

A

Protein Synthesis Inhibitor

12
Q

What is the specificty of Linezolid?

A

Gram positive organisms

13
Q

What is the MOA of Linezolid?

A
  • Binds 50S subunit

- Binds the A-site

14
Q

What is the key adverse effect associated with Linezolid?

A

Myelosuppression

15
Q

What is the general pattern of specificity regarding the protein synthesis inhibitors?

A

Broad spectrum

16
Q

What protein synthesis inhibitor is NOT broad spectrum?

A

Clindamycin

17
Q

What antibiotic class do the Sulfonamides fall into?

A

DNA synthesis inhibitors

18
Q

List the Sulfonamides.

A

Sulfadizine
Sulfamethoxazole
Sulfamethizole

19
Q

What do you need to remember about the Sulfonamides?

A

Commonly used in conjunction with another class of antibiotics

20
Q

What is the MOA of the Sulfonamides?

A
  • Structurally, these drugs are similar to PABA
  • Compete with endogenous PABA in DNA synthesis
  • Prevent DNA synthesis
21
Q

What are the key adverse effects seen with the Sulfonamides?

A

1) Hypersensitivity
2) Photosensitivty
3) Steven-Johnson Syndrome

Think S-Skin

22
Q

What type of infections are the Sulfonamides commonly used to treat?

A

UTIs

23
Q

What is the specificity of the Sulfonamides?

A

Broad

24
Q

What general class of antibiotic are the Trimethoprims?

A

DNA synthesis inhibitor

25
Q

What two drugs fall into the category of Trimethoprims?

A

Trimethoprim

Pyrimethamine

26
Q

What is the spectrum of activity for Trimethoprim?

A

Gram negative bacteria

27
Q

What is Trimethoprim commonly used to treat?

A

UTIs

28
Q

What is the MOA of Trimethoprim?

A

Inhibitor of bacterial dihydrofolate reductase i.e. DNA synthesis inhibitor

29
Q

What is the key adverse effect associated with Trimethoprim?

A

Bone marrow suppression

Megaloblastic anemia

30
Q

How are Sulfamethoxazole and Trimethoprim commonly administered?

A

Together as TMP-SMX i.e. Bactrim

31
Q

What is TMP-SMX commonly given for?

A

UTI and Prostatitis

32
Q

What class of antibiotics do the Fluoroquinolones fall into?

A

DNA sythesis inhibitors

33
Q

What drugs are Fluoroquinolones?

A
Norfloxacin
Ciprofloxacin 
Levofloxacin
Ofloxacin
Gatifloxacin
Gemifloxacin
Moxifloaxcin
34
Q

What is the specificity of the Fluoroquinolones?

A

Broad (gram positive and negative)

35
Q

What is the MOA of the Fluoroquinolones?

A

Inhibition of Topoisomerase to disrupt the unwinding of DNA

36
Q

What are the key adverse effects seen with the Fluoroquinolones?

A

1) GI disturbances
2) Bind divalent cations e.g. Ca++ and prevent absorptions
3) QT prolongation

37
Q

What is the Group 1 Fluoroquinolones?

A

Norfloaxacin

38
Q

What are the Group 2 Fluoroquinolones?

A

Ciprofloxacin
Levofloxacin
Ofloxacin

39
Q

What type of organisms are best targeted by the group 2 Fluoroquinolones?

A

Gram negative

40
Q

What are the Group 3 Fluoroquinolones?

A

Gatifloxacin
Gemifloxacin
Moxifloaxacin

41
Q

What bacteria are best targeted by the Group 3 Fluoroquinolones?

A

Gram positive

42
Q

What is the mechanism of action of Metronidazole?

A

Induction of DNA damage

43
Q

What types of organisms can be treated with Metronidazole?

A

BOTH bacteria AND protozoa

44
Q

What is unique about Metronidazole?

A

Pro-drug that must undergo reduction

45
Q

What bacteria is Metronidazole used to treat?

A

Anaerobic bacteria b/c they contain the enzyme necessary for reduction i.e. activation

46
Q

What is Metronidazole commonly used to treat?

A

C.diff –along with Vancomycin

47
Q

What are the key adverse effects of Metronidazole?

A

1) GI disturbances

2) Disulfiram-effect; thus, patients should avoid alcohol on this drug

48
Q

What the the MOA of Daptomycin?

A
  • Binds to the membrane of the bacteria
  • Forms a pore and causes membrane depolarization

*This is a bactericidal

49
Q

What is the specificity of Daptomycin?

A

Similar to Vancomycin–useful against Gram positive organisms

50
Q

What key adverse effect is associated with Daptoymcin?

A

MSK disturbances i.e.

1) Rhabdomyolysis
2) Mypoathy

51
Q

What is the MOA of Polymyxin B?

A

Detergent that punches holes in the membrane structure

52
Q

What is Polymyxin B specific for?

A

LPS i.e. it is used to treat Gram negative bacteria

53
Q

How is Polymyxin B commonly used?

A

Topically, similar to Bacitracin

54
Q

What mechanisms of resistance are associated with PCNs and Cephalosporins?

A

1) Beta-Lactamase
2) Alteration of the PBP binding to drug
2) Alteration in porin function

55
Q

What mechanisms of resistance are associated with Aminoglycosides?

A

Expression of enzymes that alter the structure of the drug

56
Q

What mechanisms of resistance are associated with Macrolides?

A

1) Drug efflux pump

2) Alteration in binding to the 50S subunit

57
Q

What mechanisms of resistance are associated with Tetracyclines?

A

Drug efflux pump

58
Q

What mechanisms of resistance are associated with Sulfonamides?

A

1) Less sensitive drug target (isozyme)
2) Increased synthesis of PABA
3) Use of alternate sources of folic acid

59
Q

What mechanisms of resistance are associated with Fluoroquinolones?

A

1) Less sensitive drug target

2) Drug efflux pump

60
Q

What mechanisms of resistance are associated with Chloramphenicol?

A

Expression of inactivating enzymes

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