Other Beta-Lactams

Question 1

what is the distribution of cephalosporins?

Answer 1

mostly extracellular

Question 2

how are cephalosporins excreted?

Answer 2

renal filtration +/- secretion

Question 3

are first-generation cephalosporins affected by penicillinase?

Answer 3

no: good activity against most Staphylococcus
used frequently for skin and bone infections

Question 4

why are first-generation cephalosporins not as reliable against obligate anaerobic bacteria, especially gram-negative anaerobes?

Answer 4

anaerobes can make cephalosporinases

Question 5

what are the common agents of first-generation cephalosporins?

Answer 5

cephalexin
cefazolin
cephapirin

Question 6

second generation cephalosporins have better ___________________ than first-generation cephalosporins

Answer 6

gram-negative activity

Question 7

what makes cefoxitin and cefotetan unique among cephalosporins?

Answer 7

good anaerobic activity: including Bacteroides fragilis
4-quadrant coverage

Question 8

what is the gram negative and positive activity like of third generation cephalosporins?

Answer 8

increased gram negative activity
slightly lower gram positive activity than first generation drugs

Question 9

what allows therapeutic concentrations of third-generation cephalosporins to cross the blood brain barrier?

Answer 9

low MICs and low to moderate protein binding

Question 10

what are the drugs of choice for bacterial meningitis?

Answer 10

third-generation cephalosporins

Question 11

what are the common agents of veterinary cephalosporins?

Answer 11

cefpodoxime proxetil
cefovecin
ceftiofur
naxcel
excenel
excede

Question 12

what are the approved uses of cefovecin in the US?

Answer 12

skin infections dogs and cats
injectable approved for use every 7-14 days in dogs and cats

Question 13

is there milk withdrawal with systemic administration for ceftiofur?

Answer 13

no

Question 14

what formulation is excede (ceftiofur crystalline free acid)?

Answer 14

repository formulation

Question 15

what is the spectrum like in carbapenems?

Answer 15

perhaps broadest spectrum of activity of any antimicrobial

Question 16

what pathogens are carbapenems very effective against?

Answer 16

staphylococci
streptococci
obligate anaerobes
Pseudomonas aeruginosa

Question 17

are carbapenems effective against E. coli?

Answer 17

yes, very

Question 18

are cephalosporins able to cross the blood brain barrier?

Answer 18

third generation cephalosporins

Question 19

what is the metabolism of cephalosporins?

Answer 19

limited, depends on agent

Question 20

how are first generation cephalosporins different than narrow-spectrum penicillins?

Answer 20

not affected by penicillinase
slightly better gram negative activity
not as reliable against anaerobic bacteria, especially gram negative anaerobes

Question 21

what is used for perioperative prophylaxis?

Answer 21

cefazolin

Question 22

for the four quadrants, how does cephalexin fair?

Answer 22

E. coli: +/-
Staphylococcus: ++
Streptococcus: +
anaerobe: *

Question 23

for the four quadrants, how does cefazolin fair?

Answer 23

E. coli: +
Staphylococcus: ++
Streptococcus: +
anaerobe: *

Question 24

what is one second-generation cephalosporin?

Answer 24

cefoxitin

Question 25

what makes cefoxitin less susceptible to cephalosporinase produced by anaerobes?

Answer 25

structurally cephamycins, not cephems

Question 26

how does cefoxitin do with the four quadrants?

Answer 26

E. coli: ++
Staphylococcus: ++
Streptococcus: +
anaerobe: +

Question 27

what allows third generation cephalosporins to cross the blood brain barrier?

Answer 27

low MICs and moderate protein binding

Question 28

what is the four quadrant coverage of cefotaxime/third generation cephalosporins like?

Answer 28

E. coli: +++
Staphylococcus: ++
Steptococcus: +
anaerobe: +/-

Question 29

what is considered the first or second tier drug for pyoderma in dogs?

Answer 29

Cefpodoxime proxetil

Question 30

what is the activity of carbapenems against the four quadrants?

Answer 30

E. coli: +++
Staphylococcus: ++
Streptococcus: +
anaerobe: +