Walters- Cephalosporins

Question 1

what are cephalosporins made up of?

Answer 1

beta-lactam + dihydrothiazine ring with side chains

Question 2

what is the main mechanism of cephalosporins?

Answer 2

same as PCNs - inhibit transpeptidase and inhibit cell wall synthesis and cause cell lysis

Question 3

what is the advantage of a cephalosporin over PCNs?

Answer 3

they are resistant to many PCNases (beta-lactamases)

Question 4

what do the first generation of cephalosporins resist?

Answer 4

Staph PCNase

Question 5

what are 3 first generation drugs of cephalosporins?

Answer 5

Cefazolin, Cephalexin, and Cefadroxil

Question 6

what are the second generation of cephalosporins used against?

Answer 6

less gram positive and more gram negative (than first) - cover PEck and H.influenza and some neisseria (HNPEcK)

Question 7

what generation is Cefaclor in and when is it used?

Answer 7

2nd generation and orally every 8 hours (associated with serum sickness)

Question 8

what generation is Cefuroxime in and how is it administered?

Answer 8

2nd - oral = ceftin and IV/IM = Zinacef

Question 9

what generation is Cefoxitin in and what is it active against?

Answer 9

2nd - Bacteroides fragilis (IV/IM)

Question 10

what generation is Cefotetan in and what does it do?

Answer 10

2nd - methylthiotetrazole side-chain antagonizes vit K = hypoprothrombinemia (must supplement with vit K)

Question 11

What coverage do the 3rd generation cephalosporins have?

Answer 11

they have much less gram positive but more gram negative

Question 12

what generation is Ceftriaxone in and what does it do?

Answer 12

3rd - 85-90% protein bound and easily displaces bilirubin from albumin (do not use if less than 3 months old unless its for gonorrhoeae conjunctivitis)

Question 13

what does Ceftriaxone have good activity against?

Answer 13

meningitis (strep pneumoniae and N. meningitidis)

Question 14

what is the FDA warning for Ceftriaxone?

Answer 14

do not use with Ca2+ containing products in patients less than 28 days old - may precipitate in kidneys/lungs and give Rxs sequentially (flush IV between Rxs)

Question 15

what can Ceftriaxone cause in children?

Answer 15

sludge (pseudolithiasis) - nausea, anorexia, epigastric distress, colic = reversible when discontinued

Question 16

what generation is Cefotaxime in and how is it used?

Answer 16

3rd - IV/IM, parent and metabolite active and increases the spectrum

Question 17

what generation is Ceftazidime in and what can it cause?

Answer 17

3rd - neurologic SE e.g. myoclonus, EEG changes with increased risk if epileptic; disorientation

Question 18

what generation are Cefpodoxime and Cefdinir in are what are they used for?

Answer 18

3rd - oral use (Cefdinir is excreted mostly unchanged = binds Fe and reddens infants faces in infants fed high Fe formula)

Question 19

what generation is Cefepime in and what does it do?

Answer 19

4th - (IV/IM) for gram - rods resistant to 3rd generation, good for CNS penetration

Question 20

what are the side effects for Cefepime? and how is it excreted?

Answer 20

neurological - disorientation, myoclonus, EEG changes, mostly renal excretion

Question 21

what generation is Cefditoren and what happens to the drug during absorption?

Answer 21

4th - pro-Rx = hydrolyzed by esterases during absorption, which activates the drug.

Question 22

what drug is considered an advanced generation cephalosporin?

Answer 22

Ceftaroline = IV proRx used for community acquired bacterial pneumonia and complicated skin and skin structure infections including MRSA

Question 23

what are the general side effects of cephalosporins?

Answer 23

hypersensitivity = risk of cross-allergy with PCN (greatest with 1st), nephrotoxicity and risk of immune-mediated hemolytic anemia