Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemotherapy > 2 - B-lactam ABX & B-lactamase Inhibitors > Flashcards

2 - B-lactam ABX & B-lactamase Inhibitors Flashcards

1
Q

4 classes of B-lactam antibiotics

A

Penicillin
Cephalosporin
Monobactam
Carbapenem

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

B-lactam MOA

A

Inhibition of peptidoglycan synthesis by binding to transpeptidase enzyme, preventing NAM amino acids to form crosslinks.

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

4 causes of B-lactam resistance

A

1) B-lactamase production
2) Modification of target PBPs
3) Impaired penetration of drug
4) Drug efflux

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

What structure does all B-lactam have in common?

A

B-lactam ring

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

How does resistance happen through B-lactamase production?

A

B-lactamase enzyme degrade the B-lactam ring

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

Structure of Penicillin?

A

B-lactam ring attached to thiazolidine ring. Different R groups yield derivatives of Penicillin.

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

Penicillin Classification?

A
  • Narrow spectrum
  • penicilinase-resistant penicillins (resistant to staphylococcal b-lactamases)
  • extended spectrum penicillins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Example of narrow spectrum penicillin

A

Penicillin G = Benzylpenicillin (iv)

Penicillin V = phenoxymethyl penicillin (oral)

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

Example of Penicillinase-resistant penicillins (resistant to staphylococcal B-lactamase)

A

Methicillin
Nafcillin
Isoxazoyl penicillins (oxacillin, cloxacillin, dicloxacillin)

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

Example of extended-spectrum penicillins

A

Amoxicillin
ampicillin
piperacillin
ticarcillin

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

Previously, the activity of penicillin G was defined in units. Semisynthetic penicillins are prescribed by?

A

Weight

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

Define penicillin stability in dry and solution state

A

dry crystalline –> years

solution –> degrade very rapidly (24 hours at 20C)

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

Which factors affect oral absorption of Penicillin?

A

Acid stability and protein binding

ex: dicloxacillin, ampicillin, amoxicillin are acid stable and well absorbed

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

All oral penicillin absorption are impaired by food except?

A

amoxicillin

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

When should oral penicillin be administered?

A

1-2 hours before or after a meal

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

Which penicillin derivative causes irritation and local pain if administered in a large dose through IM?

A

Penicillin G. That’s why IV is prefer

red

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

Which penicillin derivative are formulated to delay absorption (repository)? How long can it last?

A

Benzathine and procaine. One dose can last for 10 days.

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

Which body part receives a higher distribution of penicillin?

A

None, its equally distributed throughout the body.

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

Therapeutic concentration of penicilllins are achieved in tissue and secretions (joint fluid, pericardial fluid, bile). Which cell and 2 tissues don’t it penetrate?

A

Living phagocytic cells

1) brain tissue penetration
2) intraocular fluid

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

Penicillin is excreted into the sputum (dahak) and milk up to 15% levels present in the serum. true or false?

A

True. 3-15% of serum levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Excretion of penicillin through the kidneys occur in 2 places, one contributing 10%, one 90%. Which pathways are those?

A

10% - glomerular filtration

90%- renal tubular secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

A penicillinase resistant penicillins (resistant to staph b-lactamase) is primarily cleared by biliary excretion. Which is it?

A

Nafcillin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which penicillin are eliminated by both kidney and biliary excretion?

A

Isoxazolyl penicillins (oxacillin, cloxacillin, and dicloxacillin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why is dose adjustment of penicillin (not just by weight) required in newborns?

A

Penicillin clearance is less efficient in newborns.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which narrow spectrum penicillin is the drug of choice for infections caused by streptococci, meningococci, penicillin-susceptible pneumococci, clostridium, treponema, non b-lactamase producing gram - anaerobic organisms

A

Penicillin G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which narrow spectrum penicillin is indicated only in minor infections, and has a narrow antibacterial spectrum? How many times is it used in a day

A

Penicillin V, 4x a day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which narrow spectrum penicillin is indicated for infection caused by syphillis and b-hemolytic streptococcal pharyngitis?

A

Benzathine penicillin G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which narrow spectrum penicillin is formerly used for treating uncomplicated pneumococcal pneumonia or gonorrhea, but is now rarely used due to resistance?

A

Procaine penicillin G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which penicillin class is indicated for b-lactamase-producing staphylococci, but not for listeria monocytogenes, enterococci, and methicillin resistant strains of staphylococci?

A

penicillinase-resistant Penicillins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Extended-spectrum penicilins are further classified into 3 groups, which are:

A

Aminopenicillins, carboxypenicillins, ureidopenicillins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Extended-spectrum penicilins have greater activity than penicillin G against gram - bacteria because?

A

They have enhanced ability to penetrate the outer membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Name 2 aminopenicillins

A

Ampicillin

Amoxicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Name 2 Carboxypenicillins

A

Carbenicillin,
Carbenicillin indanyl sodium
Ticarcillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Name 3 ureidopenicillins

A

Piperacillin
Mezlocillin
Azlocillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which aminopenicilin is better absorbed orally?

A

Amoxicillin.

amoxicillin 3x a day ~ = 4x ampicilin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Name 4 aminopenicillin indications

A

UTI, meningitis, salmonella, upper respiratory tract infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Which aminopenicillin is effective for shigellosis?

A

Ampicillin

38
Q

Can aminopenicillins be used in empirical therapy of UTI, meningitis, and typhoid?

A

No.

39
Q

Which aminopenicillin can treat serious infections cased by enterococci, listeria monocytogenes, b-lactamase-negative strains of gram - cocci such as e coli and salmonella, and anaerobes (all penicillin susceptible) ?

A

Ampicillin

40
Q

Which drug is not active against microbes causing commonly encountered in hospital-acquired infections, such as klebsiella, enterobacter, p.aeruginosa, etc?

A

ampicillin

41
Q

Which carboxypenicillin is obsolete?

A

carbenicillin. It’s the 1st antipseudomonal carboxypenicillin

42
Q

Which drug class is active against some isolates of P.aeruginosa resistant to ampicillin?

A

Carboxypenicillin (ext. spect peni)

43
Q

Are carboxypenicillins effective for most strains of Klebsiella, Enterococcus faecalis, and S. aureus?

A

No

44
Q

Which drug class is effective to treat gram (-) bacilli, such as Klebsiella pneumoniae?

A

Ureidopenicillins

45
Q

Which drug combination produces the broadest antibacterial spectrum of penicillins?

A

Piperacillin (ureidopenicillin, ext. spectrum pen)+ Tazobactam (cephalosporin)

46
Q

Which drug class can aminoglycosides / fluoroquinolone be combined with to overcome resistant pseudomonal infections outside urinary tract?

A

ureidopenicillins (etx. spec peni)

47
Q

Most common adverse reaction of penicillin is due to?

A

hypersensitivity.
- Antigenic determinants: products of penicillin (penicilloic acid, products of alkaline hydrolysis)

All are cross-sensitizing and cross reacting. This extends to other b-lactam abx

48
Q

Hypersensitive incidence % of penicillin?

A

0.7 - 10%

49
Q

Name at least 3 manifestations of hypersensitivity to penicillin.

A

Maculopapular rash, urticarial rash, fever, bronchospasm, vasculitis, serum sickness, exfoliative dermatitis, stevens-johnson syndrome, shock anaphylaxis

50
Q

Aside from hypersensitivity reactions, are there other adverse reactions of penicillin?

A

-Toxic effects (bone marrow depression, granulocytopenia, hepatitis)
-impaired hemostasis in association with penicillin G, carbenicillin, piperacillin, or ticarcillin
-IM penicillin = pain
IV penicillin = phlebitis / thrombophlebitis
-Large dose orally may lead to GIT upset, nausea, vomitting, diarrhea

51
Q

Core nucleus structure of cephalosporins?

A

7-aminocephalosporanic acid

R1 side chain - B lactam ring - dihydrothiazine ring - R2 side chain

52
Q

Cephalosporins has a broad spectrum of activity. Why?

A

They’re more stable against b-lactamases.

extended spectrum b lactamases can still hydrolyze most cephalosporins.

53
Q

Name 2 1st gen Cephalosporin

A

Cefazolin

Cefadroxil

54
Q

Name 2 2nd gen Cephalosporin

A

Cefuroxime

cefamandole

55
Q

Name 2 3rd gen Cephalosporin

A

Ceftriaxone

Cefotaxime

56
Q

Name a 4th gen cephalosporin

A

cefepime

57
Q

Which class of beta-lactam is more acid stable?

A

Cephalosporins

58
Q

Which class of beta lactam antibiotic has low intrinsic antimicrobial activity, but attachment of R groups in 3rd and 7th position yields potent compounds of low toxicity?

A

Cephalosporins

59
Q

What differentiates different generations of cephalosporin?

A

Increasing generation –>

  1. increase activity against gram - bacteria and anaerobe
  2. increase resistance to b-lactamases
  3. Increase ability to reach CSF and BBB
60
Q

Route of Administration for 1st Gen Cephalosporin?

A

Parenteral (cefadroxil), and orally

61
Q

Excretion route for 1st , 2nd, 3rd, 4thgen cephalosporin?

A

Kidneys

62
Q

1st gen cephalosporin treats?

A

Staphylococcus and streptococcus skin, soft tissue infections, and UTI

63
Q

Which route of administration should be avoided for 2nd Gen cephalosporin?

A

intramuscular. It’s painful

64
Q

2nd gen cephalosporin treats?

A

sinusitis, otitis, lower respiratory tract infections

65
Q

Which 2nd gen cephalosporin can cross the BBB?

A

Cefuroxime

66
Q

Which 3rd gen cephalosporin can treat meningitis?

A

Ceftriaxone and Cefotaxime

67
Q

3rd gen cephalosporin is not used to treat?

A

Infections caused by organisms expressing extended-spectrum b-lactamase. Ex: enterobacter infections

68
Q

Which generation of cephalosporin have true broad spectrum activity?

A

4th gen

69
Q

Which gen of cephalosporin is used in empirical treatment of serious infections acquired in the hospital (nosocomial infections)?

A

4th gen

70
Q

Name 2 examples of 5th gen cephalosporin

A

Ceftabiprole, Ceftaroline

71
Q

Which generation of cephalosporin is active against MRSA (Methicillin-resistant Staphylococcus aureus)?

A

5th gen

72
Q

Name 2 adverse effect of cephalosporins!

A
  1. Allergy - hypersensitivity reaction
    ex: anaphylaxis, fever, skin rash, hemolytic anemia
    tolerable for individuals with penicillin allergy. But if patient experience anaphylaxis to penicillin, avoid ceph!
  2. Toxicity
    appear as:
    - local irritation after i.m injection (severe pain), thrombophlebitis (blood clot in vein) after iv injection
    -renal toxicity
    ceph containing menthylthiotetrazole group: - hypoprothrombinemia (deficiency of prothrombin), bleeding disorder. disulfiram reaction (due to blocking of alcohol oxidation).
73
Q

Which class of b-lactam antibiotics are active against anaerobic gram - rods, but no activity against gram + or anaerobes?

A

Monobactam

74
Q

Monobactams can penetrate well into the CSF. T/F?

A

T

75
Q

Patients that are allergic to penicillin can tolerate monobactams without any reactions. T/F, why?

A

T, because its structure is made up of only one ring structure, unlike the other b-lactam antibiotics that has a b-lactam ring and an additional ring structure attached to it.

76
Q

Name a side effect of monobactam. Does it have any major toxicity?

A

No major toxicity. Side effects: occasional skin rash and elevation of serum aminotransferases

77
Q

Which antibiotic has the broadest antimicrobial spectrum? Which organisms can it inhibit?

A

Carbapenems. Gram - and +, and anaerobes, except for organisms producing metallo-b-lactamase and carbapenemase

78
Q

2 examples of carbapenems are?

A

Imipenem and meropenem

79
Q

What are the differences between meropenem and imipenem?

A

imipenem is inactivated by dehydropeptidases (DHP) in renal rubules, while meropenems are not.

80
Q

Can carbapenems penetrate the body tissues, including CSF?

A

Yes

81
Q

How are carbapenems excreted?

A

Renally

82
Q

Carbapenem indication?

A

Infections resistant to other drugs (ex: pneumonia and sepsis). Infections caused by extended-spectrum b-lactamase-producing gram -

83
Q

State 4 common side effects of carbapenem

A

Nausea, vomiting, diarrhea, skin rashes, and reaction at infusion site.

84
Q

Side effect of imipenem?

A

seizure, especially in renal failure patients

85
Q

Patients allergic to penicillin may be allergic to?

A

carbapenem, cephalosporin,

86
Q

3 examples of b-lactamase inhibitors?

A

Clavulanic acid, sulbactam, tazobactam

87
Q

b-lactamase inhibitor is combined with extended spectrum penicillins because? Give examples.

A

the combination extends the activity of the penicillin to include b-lactamase producing strains of S aureus and some gram - bacteria.
Ex: Ampicillin - sulbactam
amoxicillin - clavulanic acid
piperacillin - tazobactam

88
Q

B lactamase inhibitors are effective on serratia. T/F?

A

F

89
Q

State 3 common features of b-lactam antibiotics

A
  1. B-lactam ring
  2. MoA
  3. Immunological property (cross sensitivity reaction)
90
Q

Why does Imipenem need to be combined with cilastin?

A

Cilastin inhibits renal dehydropeptidase (DHP) which could inactivate the imipenem.

91
Q

Which b-lactam class does not share resistance and cross-sensitivity with other beta lactam?

A

Monobactam

Chemotherapy (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions