Antimicrobials - Cell Wall Inhibitors - Carbapenems & Monobactams

Question 1

What is the suffix for carbapenems?

Answer 1

-Penem

Question 2

What is the suffix for monobactams?

Answer 2

-Nam

Question 3

How do carbapenems and monobactams block cell wall synthesis?

Answer 3

They bind to the penicillin-binding protein (PBS) which inhibits the transpeptidase enzyme

Question 4

What is the bactericidal effect dependent on?

Answer 4

The drug is time-dependent and must be at the Minimum Bactericidal Concentration (MBC). Killing power does not increase with concentration but killing power will continue as long as the drug is above the MBC.

Question 5

How do carbapenems and monobactams degrade peptidoglycan?

Answer 5

The drugs contain autolysins and murein hydrolases which destroy the bacterial cell wall (peptidoglycan)

Question 6

Name 3 drugs that are cell wall inhibitors but do not fall under the following drug classes:

Penicillins
Cephalosporins
Carbapenems
Monobactam

Answer 6

Vancomycin
Fosfomycin
Daptomycin

Question 7

Name the 4 carbapenems

Answer 7

Imipenem
Meropenem
Doripenem
Ertapenem

Question 8

Name the 1 Monobactam

Answer 8

Aztreonam

Question 9

How does fosfomycin work?

Answer 9

Fosfomycin inhibits enol-pyruvate transferase which interferes with monomer production of the peptidoglycan layer.

Question 10

How does vancomycin work and what is its effect?

Answer 10

Vancomycin inhibits transglycosylation and is bactericidal

Question 11

How does daptomycin? What is the effect?

Answer 11

Daptomycin aggregates in the membrane by inserting itself in a phosphatidylglycerol dependent manner. This destroys the membrane and kills the bacteria because ions leak out. The effect is bactericidal.