Cephalosporins, Carbapenems, and Monobactams Flashcards Preview

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Flashcards in Cephalosporins, Carbapenems, and Monobactams Deck (39):
1

List the organisms that 1st gen cephalosporins are effective against. Which is target?

Gram-pos: - MSSA (*target) - PCN-susc. Strep pneumo - Group streptococci - Viridians streptococci Grem-neg: (PEK) = - Proteus mirabilis - E. coli - Klebsiella pneumoniae

2

List the organisms that 2nd gen cephalosporins are effective against. *Which group is unique to this gen?

Gram-pos: (slightly less active than 1st gen) - MSSA (*target), PCN-susc. Strep pneumo, Group streptococci, Viridians streptococci. Gram-neg: (HENPEK) = - H. influenzae - Enterobacter spp. - Neisseria spp. - Proteus mirabilis - E. coli - Klebsiella pneumoniae (+ M. catarrhalis). Anaerobes: Bacteroides fragilis /group

3

List the organisms that 3rd gen cephalosporins are effective against. *Which is target?

Gram-neg (HENPECKSSS P) = - H. influenzae - Enterobacter spp. - Neisseria gonorrhoeae - Proteus mirabalis - E. coli - Citrobacter spp. - Klebsiella pneumoniae - Serretia marcescens - Salmonella spp. - Shigella spp.; *Pseudomonas aeruginosa (target) (still have gram-pos activity but less active than earlier gens)

4

Which 3rd gen. cephalosporin does NOT target pseudomonas, unlike the others? Which would you use instead?

Ceftriaxone - Ceftazidime

5

How does the activity of 4th gen cephalosporins change compared to 3rd gen?

Gram-pos: similar to ceftriaxone. Gram-neg: Similar to ceftriaxone but also adds: - Pseudomonas aeruginosa - Beta-lactamse-producing enterobacter spp.

6

List the categories/organisms that 5th gen cephalosporins are effective against. *Which is unique to this gen?

Resp pathogens - H. influenzae - strep. Pneumoniae - Moraxella - Staph aureus. Gram-pos + SSSI: - Strep pneumonia *MRSA*

7

*What important organisms are cephalosporins NOT active against? (6)

SMACLE - Stenotrophomonas maltophilia - MRSA (*except for the 5th gen) - Atypical bacteria (eg Legionella; cuz no cell wall) - C-diff - Listeria - Enterococcus spp.

8

All cephalosporins are eliminated via the ___________ except for ___________ and ___________ (how are each eliminated?)

- Kidney - Ceftriaxone (bile) - Cefoperazone (liver)

9

Which gens of cephalosporins are used for surgical prophylaxis?

1st and 2nd (2nd for more intense surgeries?)

10

What are some of the uses of ceftriaxone? (4 orgs)

- Uncomplicated gonorrhea (single IM dose) - CAP - PRSP - Viridans strep endocarditis

11

What's the most important organisms that 4th gen cephalosporins cover (that ceftriaxone doesn't)?

Pseudomonas

12

What are the major adverse effects of all gen cephalosporins? (2)

1. Hypersensitivity 2. C-diff

13

- Are Carbapenems broad or narrow spectrum? - What major groups are they effective against? - What are their target organisms?

- Most broad-spectrum available - Many gram-pos and gram-neg aerobes, as well as gram-pos/neg anaerobes. - Targets: MSSA, bacteroides.

14

*What organisms are carbapenems NOT effective against? (7)

*NOT effective against: MRSA, PRSP, VRE, coag-neg staph, c-dif, atypical bacteria, S. maltophila

15

-______________, a carbapenem, undergoes hydrolysis by a dihydropeptidase enzyme in the ________________ to a toxic metabolite. - Therefore, it's comarketed with _________, a DHP inhibitor (to prevents this)

- Imipenem - Renal brush border (hepatotoxic) - Cilastatin (not on test, but USMLE)

16

What major drug category do cephalosporins fall under? Carbapenems?

- Beta-lactams - Beta-lactams

17

What are carbapenem's mech of action? - Baciocidal or static? - Time or conc-dependent?

Inhibitors of cell wall synthesis by binding to and inhibiting PBPs; primary target is PBP-2 - Bacteriocidal - Time-dependent

18

Name the major carbapenems. - Which 2 are the "best"?

DIME - Doripenem (best) - Imipenem (best) - Meropenem - Ertapenem

19

What are the mechs of resistance for cephalosporins? (which is most important?)

- Beta-lactamase enzymes (most important) - PBP alteration - Decreased membrane penetration

20

Beta-lactams are all cross-allergenic except for which one?

Aztreonam

21

Are cephalosporins bacteriocidal or bacteriostatic?

Bactericidal

22

Which subset of the cephalosporins are the only ones that have activity against anaerobes? - Which generation is it in?

Cephamycins - 2nd gen

23

*What gen. cephalosporin is used for the treatment of meningitis?

3rd gen

24

When treating meningitis w/3rd gen cephalosporins, if pseudomonas is suspected or present, what specific drug would you use?

Ceftazidime

25

What is the main thing that 5th gen cephalosporins are used for?

Drug-resistant organisms

26

Why were cephalosporins developed?

Beta lactams that are less susceptable to beta-lactamase enzymes.

27

Why were carbapenems developed?

- Extended spectrum of activity - Further beta-lactamase stability

28

What are the clinical uses of carbapenems?

- Empiric therapy for HA-infections - Polymicrobial infections - Infections due to β-lactamase-producing organisms (SPICE, SPACE, others)

29

*If pseudomonas is suspected, which carbapenem would you avoid?

*Avoid ertapenem if pseudomonas suspected

30

What are the main adverse effects of carbapenems?

- CNS (e.g. seizures) - GI - Hypersensitivity

31

Do carbapenems have hypersensitivity/cross-reactivity w/PCNs like cephalosporins do?

Yes

32

What category of drug is a monobactam? - How can it be administered?

Synthetic monocyclic beta-lactam - IV

33

Monobactams are beta-lactams. What specific part of the cell wall do they target? - What is the main class of organisms they target?

PBP-3 - of gram-negative aerobes

34

Recall: what class of organisms do monobactams inhibit? - What's its main target?

Gram-neg aerobes * Pseduomonas

35

Recall: what is the class of drugs that aztreonam is a member of? Since aztreonam is the only beta-lactam that does have cross-allergencitiy, what clinical implications does this have?

- Monobactams - Can be used in PCN-allergic pts

36

What are the major adverse effects of monobactams?

N/D

37

What are the major adverse effects for 2nd gen cephalosporins, besides hypersensitivity and c-diff?

- Hypoprothrombinemia - Ethanol intolerance due to disulfiram-like rxn

38

Which gen's of cephalosporins inhibit pseudomonas?

- 3rd (except ceftriaxone) - 4th

39

Which gen of cephalosporins are effective against anaerobes like bacteroides?

2nd gen only