Cephalosporin/Monobactams/Carbapenems

Question 1

Are cephalosporins water soluble or lipid soluble?

Answer 1

Mainly water soluble

Question 2

How do cephalosporins work?

Answer 2

Same as beta-lactams.

Question 3

Are cephalosporins bactericidal or bacteriostatic?

Answer 3

Bactericidal

Question 4

Do cephalosporins work in purulent debris?

Answer 4

NO!

Question 5

What are the generations of cephalosporins:

Answer 5

First generation
Second generation
Third generation
New gen cephalosporins

Question 6

How are cephalosporins/carbapenems eliminated?

Answer 6

Mostly renal.

Question 7

What do all cephalosporins work on?

Answer 7

Staph, Strep, Pasteurella, and E. coli (Broad spectrum minus anaerobes).

Question 8

Cephalexin/Cefazolin

Answer 8

1st generation cephalosporins.
Broad spectrum minus anaerobes.
Cefazolin is the ONLY injectable 1st gen cephalosporin.
Cefazolin works better on E. coli than Cephalexin.

Question 9

Cefoxitin

Answer 9

2nd generation cephalosporin.
Broad spectrum + anaerobes and B. fragilis.
Injection ONLY!

Question 10

Ceftriaxone/Ceftazidime

Answer 10

3rd generation cephalosporin.
Broad spectrum minus anaerobes + Lyme.
ONLY ceftazidime works on Pseudomonas.
Drugs of choice in bacterial meningitis. CAN CROSS BBB.

Question 11

Ceftiofur/Cefpodoxime/Cefovecin

Answer 11

New generation cephalosporins.
Broad spectrum minus anaerobes.
Only cefovecin works on Lyme, but it doesn’t work well on E. coli.
Ceftiofur sodium (Naxcel) and Ceftiofur HCl (Excenel) have very short withdrawal times (2-4 days) for meat, and NO withdrawal for milk.

Question 12

Are monobactams/carbapenems water or lipid soluble?

Answer 12

Monobactams are seldom used in vet med, but carbapenems can cross the BBB.

Question 13

Meropenem

Answer 13

All broad spectrum bacteria + B. fragilis and Pseudomonas.