Cephalosporins-Cell wall synthesis inhibitors Flashcards Preview

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Flashcards in Cephalosporins-Cell wall synthesis inhibitors Deck (59)
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1

What are the major types of bacterial cell wall synthesis inhibitors APART from penicillins?

1) Cephalosporins
2) Carbapenems
3) Monobactams

2

Cephalosporins are not active against which organisms?

Cephalosporins are not active against Enterococci and Listeria

3

How do first generation cephalosporins compare to later generations?

1st generation are more active vs gram positive organisms (e.g. staph, streptococci), while later drugs (2nd, 3rd, 4th gen) are more active vs gram negative aerobic organisms (e.g. E. coli, etc.)

4

What generation of cephalosporin is Cefazolin?

First generation cephalosporin

5

What is the mechanism of action of Cefazolin?

Binds to PBP’s, and thereby inhibits the assembly of the bacterial cell wall, leading to bactericidal action

6

What organisms are sensitive to Cefazolin?

Sensitive: most streptococci, most S aureus (MSSA), most oral anaerobes, some sensitive GNR like E. coli

7

What organisms are resistant to Cefazolin?

Resistant: MRSA (about 30% and growing), enterococcus, nosocomial GNRs, some pneumococcus, bowel anaerobes

8

How is Cefazolin usually administered?

Usually administered IV but can be given IM

9

What toxicity is associated with Cefazolin?

Contraindicated in serious Pen-allergic patients (cross-allergy); anemia, drug allergy especially rash, analphylaxis, antibiotic-associated colitis

10

What drug interactions should be considered with Cefazolin?

probenecid inhibits renal active tubular secretion, prolongs half-life

11

What are the indications for Cefazolin?

Soft tissue infections (strep and staph)
- UTI
- Patients with mild allergies (but not anaphylaxis) to penicillins
- Surgical prophylaxis (e.g. just before appendectomy or hysterectomy)

12

What is the mechanism of action of Ceftriaxone (3rd generation cephalosporin)?

Binds to PBP’s, and thereby inhibits the assembly of the bacterial cell wall, leading to bactericidal action; more active against many GNRs which produce beta-lactamases

13

What organisms are sensitive to Ceftriaxone?

Sensitive: streptococci, most (>90%) pneumoccus, many S aureus (only MSSA), most oral anaerobes, Neisseria, Most gram negative rods, Lyme disease

14

What organisms are resistant to Ceftriaxone?

Resistant: MRSA (about 30% and growing), 5-10% pneumococcus, bowel anaerobes, enterococcus, nosocomial GNRs, bowel anaerobes, pseudomonas, and Listeria

15

How is Ceftriaxone generally administered?

Usually given IV, but can be given IM

16

What toxicity is associated with Ceftriaxone?

Contraindicated in serious Pen-allergic patients (cross-allergy); anemia, drug allergy especially rash, anaphylaxis, antibiotic-associated colitis

17

What drug interactions should be considered with Ceftriaxone?

-Probenecid inhibits renal active tubular secretion - Synergistic with gentamicin against some gram negative rods
- May enhance effects of warfarin

18

What are the indications for Ceftriaxone?

Meningitis, serious pneumonia, gonorrhea, otitis, sinusitis

19

To what generation of cephalosporin does Ceftazidime belong?

3rd generation cephalosporin

20

What is the mechanism of action of Ceftazidime?

-Binds to PBP’s, and thereby inhibits the assembly of the bacterial cell wall, leading to bactericidal action
- More active against many GNRs which produce beta-lactamases

21

What organisms are sensitive to Ceftazidime?

Sensitive: some streptococci, but most effective against many GNRs, including most PSEUDOMONAS strains

22

What organisms are resistant to Ceftazidime?

Resistant: large majority of staph, some pneumococcus, bowel anaerobes; good at inducing resistance

23

How is Ceftazidime usually administered?

IV but can be given IM

24

What toxicity is associated with Ceftazidime?

Contraindicated in serious Pen-allergic patients (cross-allergy); drug allergy especially rash, anaphylaxis, antibiotic-associated colitis

25

What drug interactions should be considered with Ceftazidime use?

-Synergistic with gentamicin against some GNR, especially Pseudomonas
- May enhance effects of warfarin

26

What are the indications for Ceftazidime?

- Infections where resistant GNRs and Pseudomonas are likely
- Meningitis or sepsis where GNR is likely pathogen
- Bacteremia, UTI, urosepsis
- Empiric Rx of febrile neutropenic pts

27

To what generation of cephalosporin does Ceftaroline belong?

- “5th generation” cephalosporin
- Amazingly active against GNR (like the 3rd and 4th generation drugs), but also active against GPC like staph aureus, including both MSSA and MRSA

28

What is the mechanism of action of Ceftaroline?

Binds to PBP’s, and thereby inhibits the assembly of the bacterial cell wall, leading to bactericidal action; more active against many GNRs which produce beta-lactamases

29

What organisms are sensitive to Ceftaroline?

Sensitive: many GNR (E. coli, Klebsiella, H. influenza)
-Many GPC, including Str. pneumoniae, both MSSA and MRSA

30

How is Ceftaroline generally administered?

IV but can be given IM