Cell Synthesis Inhibitors that are not beta lactams

Question 1

What is vancomycin? MOA?

Answer 1

cell synthesis inhibitor

not a beta lactam

Binds to D-Ala-D-Ala nascent ends of peptidoglycan peptides –> prevents peptidoglycan formation –> stops cell wall synthesis

Bacteriocidal

Question 2

Vancomycin, what do you think of?

Answer 2

Van = big
So big it cant make it’s way into gram negatives - only kills gram positive

and so big that we need to give it slow IV –> can potentially lead to infusion reaction (red man/ red neck syndrome)

Question 3

Vancomycin spectrum?

Answer 3

gram positive only (remember the van is so big it cannot enter gram negatives)

• *** Kills multidrug resistant organisms
• MRSA (methicillin res s. aureus)
• enterococci ?????
• PRSP (penicillin resistant strep pneumonia)

Question 4

Vanomycin susceptible to beta lactamases?

Answer 4

Vanocmycin is not a beta lactamase –> no

Question 5

What is the stepwise order of anti-bac treatment?

Answer 5

Penicillin –> cephalosporin –> carbapenem –> monobactam –> vancomycin –> daptomycin –> bacitracin –> fosfomycin

Question 6

Vancomycin is used to treat?

Answer 6

Beta Lactam resistant, gram positive organisms

eg. MRSA

People that are SEVERELY allergic to beta lactams

Question 7

Vancomycin admin?

Answer 7

Poor oral absorption so

slow IV –> can get red man/ red neck syndrome
can also get accumulation –> ototox and nephrotox

Question 8

Vancomycin AE?

Answer 8

Accumulation —> ototoxicity and nephrotoxicity

Question 9

Vancomycin combination therapy?

Answer 9

give with aminoglycosides (protein synthesis inhibitor)
-makes it easier for the aminogly to get inside of the cell

1) Empiric tx: infective endocarditis
* penicllin can also be used in place of the vancomycin, nut isnt really used anymore because of increasing resistance

2) tx Penicillin Resistant Strep Pneumonia (PRSP)

Question 10

Vancomycin is used to treat?

Answer 10

Staph. enterocolitis

Pseudomembranous colitis (c. dificile) caused by

• ampicillin
• cephalosporins

Question 11

Does vancomycin penetrate the CSF?

Answer 11

yes, when inflamed

Question 12

Daptomycin? MOA? Bacteriocidal?

Answer 12

New mechanism! (just like dapping ie.dabbing is new)
Therefore it is useful against multidrug resistant bacteria!

binds to the cell membrane by Ca dep insertion of its lipid tail

depol cell –> K Efflux (weird) –> cell death

Yes, bacteriocidal

Question 13

Daptomycin spectrum?

Answer 13

kills multidrug resistant organisms because of novel MOA

• gram positive only
• MRSA
• enterococci and VRE (vancomycin res enterococci)
• VRSA (vancomycin resistant staph aureus)

^^similar to vancomycin + vanco resistant things minus PRSP

PRSP : penicillin resistant strep. pneumonia
NOT effective at killing pnuemonia because the surfactant in the lungs inactivates the daptomycin

Question 14

Daptomycin admin?

Answer 14

it is large –> IV only
-can accumulate –> renal insuff

*recall vancomycin: slow IV only (nephrotox and ototox)

Question 15

When is daptomycin contraindicated?

Answer 15

Creatine kinase elevated
indicates myopathy

stop using statins

Question 16

Bacitracin MOA?

Answer 16

not specified
just know, LATE cell wall synth
mechanism is unique –> no cross resistance

Question 17

Bacitracin admin?

Answer 17

topical mainly

-because oral –> nephrotoxicity (v large molecule)

Question 18

Bacitracin spectrum?

Answer 18

gram positive only

so are vancomycin and daptomycin

Question 19

Fosfomycin MOA?

Answer 19

inhibits cytoplasmic enzyme : enolpyruvate transferase

EARLY cell wall synth

Question 20

Fosfomycin spectrum? What is it used to treat?

Answer 20

Gram positive AND negative

only one of the cell wall inhibitors (not incl beta lactams) that includes gram negative

therefore used to treat 
uncomplicated UTIs (mostly gram neg)