Exam 7: Cephalosporins

Question 1

2 First Gen Cephalosporins

Answer 1

Cefazolin
Cephalexin
Most of them have a “ph” in their name.

Question 2

4 Second Gen Cephalosporins

Answer 2

Cefaclor
Cefoxitin
Cefuroxime
Cefprozil
The FAM(ily) is gathered, some wearing FUR coats, and your FOX(y) cousin is drinking TE(a) and taking PRO(zac) while driving her CAR. It’s Nic(e) to have Met(life) insurance.
Sweet Jesus.

Question 3

4 Third Gen Cephalosporins

Answer 3

Ceftriaxone
Cefixime
Ceftaxime
Ceftazidime
Most have a T in their name except for the "fix" one (you have to FIX the car you drove in the second generation mnemonic)

Question 4

4th Gen Cephalosporin

Answer 4

Cefepime

Question 5

5th Gen Cephalosporin

Answer 5

Ceftaroline

Question 6

What structural feature do Cephalosporins share with Penicillins?

Answer 6

Beta Lactam Rings

Question 7

How can we change Cephalosporin structure to affect function?

Answer 7

changes are R1 affect antibacterial properties

Changes are R2 affect metabolism and pharmacokinetics

Question 8

Mechanism of action of Cephalosporins

Answer 8

same as penicillins
Inhibit cell wall synthesis (act on transpeptidase/PBP)
Killing effect

Question 9

Which Cephalosporin has the longest half life?

Answer 9

Ceftriaxone

Question 10

Which cephalosporins cannot be used for meningitis? Why?

Answer 10

1st and 2nd generation
They don’t have good penetration into the CNS (except for Cefuroxime, but it doesnt treat the bugs that cause meningitis anyway)

Question 11

Which Cephalosporins can treat Meningitis?

Answer 11

Some 3rd generations (Ceftriaxone, Ceftaxone, Ceftazidime)
Also Cefepime
Maybe Ceftaroline in the future

Question 12

Cephalosporin metabolism/excretion

Answer 12

Excreted by the kidneys via the organic acid secretory system and by glomerular filtration.
Adjust dosage with renal failure
Ceftriaxone is different (excreted in bile)

Question 13

Ceftriaxone excretion

Answer 13

Mainly excreted in the bile

No need to adjust for renal failure

Question 14

Who shouldn’t get Cephalosporins?

Answer 14

Patients with a history of severe reactions to Penicillin family members
If their reaction to penicillins is very mild, you can cautiously try cephalosporins.
There is no skin test to predict allergic reactions to cephalosporins.

Question 15

Adverse Effects of Cephalosporins

Answer 15

Alcohol intolerance, especially with Cefalozin (buildup of acetaldehyde because of aldehyde dehydrogenase inhibition)
Methythiotetrazole in the R2 position seen in Cefalozin is associated with particularly bad EtOH reaction
Bleeding disorders (kills off Vit K producing bacteria). Again, Cefalozin is especially bad here.
Also nephrotoxicity, seizures, GI problems, opportunistic infections.

Question 16

How can you prevent bleeding disorders with Cephalosporin administration?

Answer 16

Vit K supplementation

Question 17

Resistance Mechanisms to Cephalosporins

Answer 17

Beta lactamase (later generations are less and less susceptible to this)
First generations are easily broken down by beta lactamase
Cofaclor (2nd gen) is also susceptible.

Question 18

What are 3rd gen Cephalosporins best at treating?

Answer 18

Gram Negatives
Strep pneumo
(Not good with most gram positives)

Question 19

What are 2nd gen Cephalosporins best at treating?

Answer 19

Pretty equal at gram negative, strep pneumo, and gram positives

Question 20

What are 1st gen Cephalosporins best at treating?

Answer 20

Strep pneumo
Gram positives
(Not good with Gram Negs)

Question 21

First Gen Cephalosporin activity

Answer 21

Gram positives
Oral cavity anaerobes
Some gram negative enteric

Question 22

Cefazolin

Answer 22

First gen cephalosporin
Drug of choice for surgical prophylaxis *** (probably on test)
Staph and strep infections in patients allergic to penicillins
Other minor infections
Not used for serious systemic infections

Question 23

Second Generation Cephalosporin Activity

Answer 23

Gram positives (not as good as 1st gen)
Gram negatives like H flu, Moraxella (better than 1st gen)
Good for Upper respiratory infections because of this
Some anaerobic coverage
Cefoxitin has activity against Bacteroides fragilis and is used for mixed anaerobic infections
Never used for meningitis

Question 24

Third Generation Cephalosporin Activity

Answer 24

More active against gram negatives than second generation
Less effective than first gen with gram positives
Useful against beta lactamase producing Neisseria and H flu
Wide use for many types of infections

Question 25

Ceftazidime

Answer 25

3rd gen Cephalosporin

Active against Pseudomonas

Question 26

Ceftriaxone and Cefotaxime

Answer 26

3rd gen Cephalosporins

Activity against penicillin-resistant Strep pneumo

Question 27

First line therapy against Gonorrhea

Answer 27

Ceftriaxone followed by Cefixime (3rd generations)

Probably also use a macrolide or another antibiotic due to resistance.

Question 28

Meningitis Cephalosporin Therapy

Answer 28

3rd Gen cephalosporins because they can cross BBB and have activity against meningitis agents
Ceftriaxone, Cefotaximi, Ceftaxidine
Add Ampicillin if you suspect Listeria

Question 29

Lyme Disease Cephalosporin

Answer 29

Ceftriaxone treats neurological complications

Question 30

Cefepime

Answer 30

4th gen cephalosporin
More resistant to beta-lactamases
Useful against Gram negatives that are resistant to 3rd gen
Useful against Enterobacter infections (UTI)
Active against penicillin-resistant Strep

Question 31

Ceftaroline

Answer 31

5th gen cephaosporin
Activity against MRSA!!!***
Used for community acquired pneumonia and skin infections caused by Staph aureus/MRSA