LEC 16,17 - Inhibitors of Cell Wall Synthesis Flashcards Preview

Pharmacology II > LEC 16,17 - Inhibitors of Cell Wall Synthesis > Flashcards

Flashcards in LEC 16,17 - Inhibitors of Cell Wall Synthesis Deck (104):
1

What are the beta-lactam antibiotics?

Penicillin 

Cephalosporin 

Carbapenems 

Monobactams

2

What is polymixin used for?

Topically to treat Gram (-) infections in skin + eye + ear 

 

3

What are the five ways that a bacteria can become resistant to pencillin?

Inactivation 

Decreased permeability 

Alteration to PBP 

Autolytic enzymes not activated 

Lack of Cell wall

4

What must imipenem be given with? Why?

Cilastatin 

Rapidly inactivated by renal tubule dehydropeptidases. Cilastatin is a dehydropeptidase inhibitor  

5

What is the general activty of ertapenem?

Wide variety of

gram+

gram-

anaerobic

Eneterobateriaceae 

 

6

bacterial target of pencillinase resistant penicillins

Low activity againse certain gram +'s 

Resistant to penicllinase 

DOC - penicillinase producing Staphylocccocus areus 

7

Which of the natural penicillins are resistant to gastric acid?

Penicillin V 

8

How does B-lactamase stop B-lactams from being active?

Cleaves the B-lactam ring 

9

What is the general activity of carbaenems?

Broad spectrum 

Anaerobes 

Gram (+) 

Gram (-) rods 

10

Antipseudomonal penicillins (2) 

Piperacillin 

Ticarcillin 

11

How are cephalosporins excreted?

Unchanged by the kindey 

12

What are your two atypical bacteria?

Chlamydia 

Mycoplasma

13

What are the specific bacteria that 1st gen cephalosporins are good against?

E. Coli 

Klebsiella pneumoniae 

Proteus mirabilis 

14

How do the glycopeptides work?

Sterically inhibit addition of subunits to the peptidoglycan backbone

15

What are the bacterial targets of antipseudomonal penicillins?

Those covered by extended spectrum penicillins + addition gram negative bacilli 

NO KLEBSIELLA 

Major treatment for Pseudomonas aeruginosa

16

What is the function of the cell wall in bacteria?

Bacteria are hyperosmolar to their environment. The cell wall prevents osmotic rupture 

17

What is the adverse effects of imipenem?

Seizures can occur with high levels 

Use carefully in patients with brain lesion, head trauma , or hx of CNS disorders 

18

What is the general structure of gram positive bacteria?

Only layered structure external to cell membrane and is thick 

19

Route of Admin - Pen G procaine

IM 

20

What cephalosporin is the only one allowed in food animals?

Cephapirim 

Cows, pigs, turkey, and chickens 

21

Use - Ceftiofur

Respiratory infections

22

What is the big difference between bacteria and mammialian cells?

Rigid cell wall external to the cell membrane

23

How is vancomycin excreted?

Primarily unchanged via the kidney 

 

24

What is Penicillin G not effective against?

Amoebae 

Plasmodia 

Rickettsiae 

Fungi 

Virus

25

Route of Admin - Pen G potassium 

IV + IM 

26

What is the real reason behind the loss of cell-wall integrity following treatment of CWSi?

Bacteria's own cell wall remodeling enzymes aka autolysins 

Cleave peptidoglycan bonds 

27

If choosing carbapenems for a pseudomonas infection how is recommended to be given? WHy?

resistance occurs quickly 

Give with aminoglycoside 

28

Carbapenems (3)

Imipenem 

Meropenem 

Ertapenem 

29

What is the rank of antipseudomonal activity?

Piperacillin > Ticarcillin

30

When should doses of cephalosporin be adjusted?

Renal impairment 

31

Penicillinase ressitant penicillins (3) 

Oxacillin 

Cloxacillin 

Methicillin 

32

How does bacitracin work?

Inhibits the conversion to its active form of the lipid carrier that moves water soluble cytoplasmic peptidoglycan subunits through cell membrane to cell exterior 

33

Use - Cefovecin

Skin and soft tissue infections

34

What is a very important thing to remember about monobactams (aztreonam) when it comes to theraputic use?

No cross sensitivty with penicillin, can give it to those who are allergic 

35

B-lactamase inhibitor combo - Piperacillin 

Tazobactam 

36

What are the adverse effects of monobactams?

Phlebitis 

Skin rash 

Abnormal liver function

37

Route of Admin - Penicillin V 

Oral

38

Use - Cefpodoxime 

Skin and soft tissue infections in dogs

39

Natural penicillins (4) 

Penicillin G potassium 

Penicillin G benzathine 

Penicillin G procaine 

Pencillin V 

40

How are natural penicillins excreted?

Active transport in the kidney 

41

What is vancomycin useful against?

Penicillin + methicillin resistant staphylococcus aureus 

Treating gram (+) infections in penicillin allergic patients

42

how can you prolong the time penicillin stays in the body? How does it work?

Give probenecid 

Tubular secretion partially blocked by probenecid 

Used for severe infections 

43

Can you take antipseudomonals orally?

Acid sensitive

44

Where is PBP located?

On the cytoplasmic membrane

45

What are the three groups of polymyxins?

Monobactams 

Carbapenems 

Others...

46

Where is the antibacterial activity located in penicillin?

Intact B-lactam ring

47

What are the symptoms of penicillin toxicity?

Mostly just allergic reactions 

Anaphylactic 

Cytotoxic 

Arthus 

Cell mediated 

48

What are the the six major groups of drugs that inhibit cell wall formation?

Polymyxins 

Natural penicillins 

Penicillinase 

Resistant penicillins 

Extended spectrum penicillins 

Antipseudomonal penicillins 

Cephalosporins 

49

1st gen cephalosporins (4)

Cefazolin 

Cefadroxil 

Cephalexin 

Cephapirim

50

What is the general activty of 4th gen cephalosporins?

More resistant to B-lactamases 

51

What do B-lactamase inhibitors not work against?

Methicillin-resistant, penicillinase-producing, Staphylococci 

52

What is the structure of the bacterial cell wall? 

Resistant to osmotic lysis in both gram positive and gram negative due to peptidoglycan 

Convalently linked sacculus that surrounds bacterium 

53

What are the two ways vancomycin inhibits cell wall synthesis?

1 - binding to D-ala-D-ala terminus of peptidoglcan peptide = prevention of crosslinking 

2- inihibits transglycosylation which inhibits elongation of peptidoglycan and chain

54

What does resistance form against vancomycin?

1 - D-ala-D-ala replaced with D-ala-D-lactate 

 

55

B-lactamase inhibitor combo - Amipicillin 

Sulbactam 

56

What is the upside to using ertapenem?

Highly stable against beta-lactamases 

 

57

What are the gram - bacteria that are targeted by extended spectrum penicillins? (5) 

E. Coli 

Salmonella 

Shigella 

H. influenzae 

Proteus 

58

What is the major characteristic of penicillin excretion?

one of the fastest drugs to be excreted renally 

59

Why is polymixin not used parenteral?

Too nephrotoxic 

60

Use for cefazolin

surgical prophylaxis 

61

What is the mechanism by which bacitracin works?

Interferes with final dephosphorylation step in the phospholipid carrier cycle 

Impedes on mucopeptide transder to growing cell wall 

62

Why is parenteral bacitracin used with extereme caution?

Serious nephrotoxicity 

63

What is the general structure of gram negative bacteria?

Outer membrane external to very thin peptidoglycan layer

64

How is bacitracin most commonly used?

Prevent superficial skin + eye infections following minor injuries

65

What is polymixin B normally combined with?

Bacitracin for broad spectrum antibacterial effects 

66

What are the gram + exceptions to 1st gen cephalosporin susceptibility?

Enterococci 

MRSA 

67

What is the requirement for biological activity of penicillin?

Penicillin nucleus 

68

What are the extra bacterial targets of the antipseudomonal pencillins?

Proteus 

Enterobacter

69

What is the general activity of 2nd gen cephalosporins?

Increased activity against gram (-) 

70

4th gen cephalosporin (1) 

Cefepimes

71

What drugs are contraindicated when using CWSi?

Protein synthesis inhibitors

72

What is the general activity of 1st gen cephalosporins?

good activity - gram + (cocci most) 

moderate activity - gram - 

 

73

What is the mechanism of action for polymixin B?

Interacts with phospholipids in bacterial cell wall membrane to produce a detergent-like effect + membrane disruption 

 

74

What are the four things that cephalosporins do not work against?

MRSA 

Listeria monocytogene s

Enterococci 

Atypicals

75

What group of bacteria are ICWS most effective against?

Gram + 

76

How is penicillin excreted?

10% glomerular filtration 

90% tubular secretion

77

B-lactamase inhibitor combo - Ticarcillin 

Calvulanic Acid 

78

When is polymixin B administered orally?

Cattle + Swine 

Treatment of Gram (-) enteric infections

79

When can polymixin B be used parenterally?

Severe cases in horses

80

Extended spectrum penicillins (2) 

Ampicillin 

Amoxicillin 

81

How is resistance to b lactamase inhibitors occurring?

Develope independently upon b-lactamase production 

altered PBP production

82

What is the general activity of 3rd gen cephalosporins?

less active against gram + cocci 

more active against Enterobacteriaceae 

83

How do b-lactams function?

Prevent cross-linking reaction called transpeptidation

84

How do the CWS inhibitors cause cell death?

Osmotic lysis 

85

Route of Admin - Pen G bezathine 

IM 

86

What is the general activity of Bacitracin?

Gram (+) 

87

What bacteria lack a cell wall?

Mycoplasma L forms 

Chlamydia 

88

What are the regulations of vancomycin use in food animals 

89

Monobactams (1)

Aztreonam

90

2nd gen cephalosporin 

Cefoxitin 

Cefaclor 

91

What are the bacterial targets of extended spectrum penicillin?

Lower gram + coverage 

Extended gram - coverage 

Anaerobic coverage (w/ penicillinase inhibitors) 

92

What are the adverse reactions to vancomycin?

Hypersensitivty 

Ototoxic 

Nephrotoxic 

Uremia 

93

What are the bacteria that do not have the autolytic enzymes activate and therefore are tolerant to penicillin?

Listeria 

Staphylococci 

94

What does vancomycin have synergistic effects against?

Aminoglycosides 

95

What are the glycoeptides?

Vancomycin 

96

Use - Cefixime 

Skin + Soft tissue + Urinary infections

97

What is the general activity of monobactams?

Relatively resistant to beta-lactamases 

Active against gram(-) rods (pseudomonas) 

No activity against gram + or anaerobes 

98

What are the drugs the b lacatamase inhibitors are added with?

Ampicillin 

Amoxicillin 

Ticarcillin 

Pipercillin 

99

What specific bacteria do ICWS work the best against?

Pseudomonas aeruginosa 

100

B-lactamase inhibitor combo - Amoxicillin 

Clavulanic acid 

101

When is polymixin B bactericidal?

Gram (-) organism 

102

What are the three B-lactamase inhibitors?

Clavulanic acid 

Sulbactam 

Tazobactam 

103

Two other cell wall synthesis inhibitors that are not in groups

Vancomycin 

Bacitracin 

104

3rd gen cephalosporins 

Ceftiofur 

Cefovecin 

Cefixime 

Cefpodoxime