Non-PCN, Non-Ceph Cell Wall Synthesis Inhibitors

Question 1

What are the half-lives of the carbapenems?

Answer 1

All but Ertapenem are 1hr

Ertapenem = 4 hrs (once daily)

Question 2

Which carbapenems penetrate CS fluid in presence of inflamed meninges?

Answer 2

Imipenem and Meropenem

Question 3

In terms of coverage, what is special about carbapenems?

Answer 3

Most broad spectrum compared to the rest of antimicrobials

Question 4

What do carbapenems cover?

Answer 4

G+, G-, Anaerobes

Question 5

Which carbapenem covers Pseudomonas bug?

Answer 5

Doripenem

Question 6

Which carbapenem is used for CNS infection?

Answer 6

Meropenem

Question 7

What do monobactams (Aztreonam specifically) cover?

Answer 7

PBP 3 of G- aerobes; little to no activity against G+ or anaerobes

Question 8

What is the half-life of Aztreonam?

Answer 8

About 2 hrs

Neonates (7 days old and less than 2.5kg) = 5.5 to 10 hrs

Adults w/ renal impairment = 8 hrs

Question 9

With Aztreonam, can you take it if a patient has a rash due to penicillin or other B-lactams?

Answer 9

Yes, no cross-reactivity

Question 10

How does Aztreonam work?

Answer 10

Interacts w/ pen-binding proteins and induces formation of long filamentous bacterial strucutures

Question 11

What are the main glycopeptides?

Answer 11

Vanco + Telavancin

Question 12

How do the glycopeptides work?

Answer 12

1. Inhibit bacterial cell wall synthesis different than B-lactams
2. Inhibits synthesis/assembly of second stage of peptidoglycan polymers
3. Bind firmly to D-ala D-ala which inhibits additonal peptidoglycan units to grow

Question 13

What can Vanco and Telavancin cover?

Answer 13

G+, MRSA

Question 14

What are some AE of vanco?

Answer 14

1. Red-Man Syndrome (related to rate, just lengthen infusion)
2. Ototoxicity
3. Rash

Question 15

What are some AE of Telavancin?

Answer 15

1. Metallic/soapy taste
2. N/V
3. Foamy urine

Question 16

What is the blackbox warning of Telavancin?

Answer 16

Preg Category C + abnormal fetal development

Question 17

How does Dapto work?

Answer 17

Binds to bacterial membrane (not wall) and causes depolarization of membrane potential, which inhibits protein, DNA and RNA synthesis. Cell lysis does not occur

Question 18

What does Dapto cover?

Answer 18

MRSA + VRE (vanco resistant E. faecium)

Question 19

What are some AE of Dapto?

Answer 19

1. Myopathy

2. Creatine phosphokinase elevation (monitor weekly and consider suspending statins)

Question 20

How does Bacitracin work?

Answer 20

Inhibits incorporation of AA into cell wall by inhibiting dephosphorylation of phospholipid carrier cycle + damages cell membranes