Beta-Lactam Iii Antibiotics And Other Inhibitors Of Cell Wall Syntheses

Front 1

What is the structure of monobactams and what is an example of one?

Back 1

aztreonam; a monocyclic beta-lactam ring (vs. penicillins and cephs which have a bi-cyclic beta-lactam ring), a thiazolide ring, a secondary amino side chain.

Front 2

can penicillin allergic patients tolerate monobactams without a reaction?

Back 2

YES THEY CAN!!!!!!!!!!

Front 3

What type of killing do monobactams do?

Back 3

Time dependent killing-depends on sustained concentrations above MIC of organism.

Front 4

What is the mechanism of action of of monobactams?

Back 4

acetylation of transpeptidases that make cell wall.

Front 5

What is a mechanism of resistance to monobactams?

Back 5

affected by Beta-lactamases, especially Klebsiella's

Front 6

How is aztreonam administered?

Back 6

IV only!

Front 7

How is aztreonam eliminted?

Back 7

Urinary excretion of drug unchanged-adjust the dose in renal patients!

Front 8

What does aztreonam (monobactam) cover?

Back 8

Gram - rods, including Pseudomonas. No Gram + coverage at all OR anaerobes.

Front 9

What is an indication for aztreonam (monobactam)?

Back 9

penicillin allergic patients who require broad spectrum Gram - coverage for nosocomial infections (sepsis, nosocomial pneumonia and febrile neutropenia)

Front 10

What are some adverse effects of monobactams?

Back 10

Skin rash, nausea, vomiting diarrhea, elevations in serum aminotransferases.

Front 11

What are the structures of carbapEn=mS?

Back 11

Related to beta lactams, substitution of C for S atom and addition of double bond to penicillin nucleus.

Front 12

Is there any cross reactivity between penicillin allergic patients and carbapenems?

Back 12

Yes, up to 50% of patients will react.

Front 13

What is the mechanism of action for crbapenems?

Back 13

Binds bacterial peptidases, the penicillin binding proteins.

Front 14

Are carbapenems resistant to most bacterial beta-lactamases?

Back 14

YES! Except- metallo-beta-lactamases.

Front 15

What is a mechanism of resistance for Enterococcus faecium?

Back 15

Alteration of PBP

Front 16

What is a mechanism of resistance for Pseudomonas?

Back 16

modification of cell membrane to prevent penetration.

Front 17

How are carbapenems given? Do they penetrate CSF? How are they eliminated?

Back 17

IV only; YES; renally-adjust dose in renal patients

Front 18

What are the indications for carbapenem administration?

Back 18

Enterobacter, Citrobacter, Serratia, Acinetobacter, E. coli and Klebsiella

Front 19

Name some carbapenems

Back 19

Imipenem/cilastatin, meropenem, ertapenem, doripenem.

Front 20

What does Imipenem/cilistatin cover

Back 20

Gram- bacilli, Gram + cocci, anaerobes (NOT active against Enterococcus Faecium, MRSA, C. diff, Chlamydia, Mycoplasma)

Front 21

How are imipenems inactivated and what problem does this pose?

Back 21

Inactiviated by Dihydropeptidases in the renal tubules and produce toxic metabolite so have to be administered with dihydropeptidase inhibitor (Cilistatin)

Front 22

Side effects of Imipenem/cilistatin include?

Back 22

Lots of shit including seizures in less than 1%. Risk for seizures increased with Hx of seizure, loss of CNS activity or inadequate dosing in renal dysfunction.

Front 23

Why is Imipenem/cilistatin not recommended for meningitis?

Back 23

risk of seizure.

Front 24

What is meropenem used for?

Back 24

less likely than Imipenems to cause seizures so can be used for meningitis;

Front 25

Ertapenem active against?

Back 25

Gram+ and Gram- aerobic and anaerobic bacteria. NOT against MRSA, Pseudomonas or Enterococcus.

Front 26

What is an advantage to using Ertapenem?

Back 26

Once daily dosing.

Front 27

What is an indication for Ertapenem?

Back 27

Intra-abdominal infections; CAP; skin and soft tissue infections.

Front 28

Doripenem activity

Back 28

Many Gram - bacilli, including Pseudomonas, Gram + cocci and anareobes.

Front 29

What is an indication for Doripenem?

Back 29

Intraabdomial infection and complicated UTIs.

Front 30

How to select a carbapenem. Three questions.

Back 30

1) Is this a CAP like E. Coli, Kleb?
-If yes=>use ERTAPENEM
2) Is this a nosocomial ICU bug?
-If yes=>must ask third question:
3) Risk of seizure
-If yes=> give meropenem or doripenem
-If no=> give imipenem, meropenem or doripenem.
***Take home point: use Ertapenem for CAP, use the other three for ICU bugs but not Imipenem if there is seizure risk present.

Front 31

What is the action of Vancomycin?

Back 31

Inhibits cell wall syntheses by binding to D-ala-D-ala; prevents elongation of peptidoglycan; acts a step earlier than penicillin so no resistance.

Front 32

Are enterococci resistant to Vanco?

Back 32

Yes! How=> Terminal D-ala gets replaced by a D-lactate in E. faecalis and E. faeciuml Terminal D-ala gets replaced by D-serine in other enterococcus vanco can't bind these substituted amino acids as well

Front 33

What is VRE

Back 33

Vancomycin Resistant Enterococcus

Front 34

Is staph resistant to Vanco?

Back 34

Yes, some. In VISA (intermediate resistance) thicker cell wall...In VRSA gene similar to enterococci for D-ala substitution.

Front 35

What is the activity of Vanco?

Back 35

Only covers gram + organisms, partiularly staph.

Front 36

Vanco is the drug of choice for what?

Back 36

MRSA, Corynebacterium JK, MDR Strep pneumo.

Front 37

Vanco has synergistic killing with aminoglycosides against which organisms?

Back 37

Enterococcus.

Front 38

Is Vanco absorbed from the GI tract?

Back 38

NO.

Front 39

What is the only oral use of Vanco?

Back 39

Treatment of C. diff colitis.

Front 40

Does vanco reach the CSF?

Back 40

Yes.

Front 41

What is the elimination of Vancomycin?

Back 41

Renal-accumulates in renal insufficiency.

Front 42

Does Vanco exhibit time dependent killing?

Back 42

Yes!

Front 43

Indications for Vancomycin?

Back 43

MRSA, meningitis caused by penicillin resistant pneumococci ( with ceftriaxone), surgical prophylaxis in penicillin allergic patients.

Front 44

What are some major side effects for vanco?

Back 44

Phlebitis at injection site, ototoxicity, nephrotoxicity, red man syndrome-infusion related flushing caused by histamine), rash-IgA bullous disease (stop vanco and give steroids)