Antibiotics General Structure/MOA

Question 1

PCN General Structure

Answer 1

Beta-Lactam Ring; Thiazolidine Ring; Acyl Side Chain

Question 2

Beta-Lactam Ring; Thiazolidine Ring; Acyl Side Chain

Answer 2

PCN General Structure

Question 3

PCN MOA

Answer 3

Inhibits Cell Wall Formation

Question 4

PCN Mechanism of Resistance

Answer 4

Enzyme inactivation - Beta-Lactamase

Altered PCN binding Proteins (PBPs)

Question 5

What are the three clinical issues for PCNs

Answer 5

1) Dose adjustment needed for renal d/o
2) Strep pneumo is becoming increasingly resistant
3) Time above MIC is critical to PCN success. 50% of the time the level needs to be above MIC.

Question 6

Cephalosporin General Structure

Answer 6

Beta-Lactam Ring; Dihydrothiazine Ring; Acyl Side Chain

Question 7

Beta-Lactam Ring; Dihydrothiazine Ring; Acyl Side Chain

Answer 7

Cephalosporin General Structure

Question 8

Cephalosporin MOA

Answer 8

Binds to PBPs and interferes with cell wall synthesis (similar to PCNs)

Question 9

Cephalosporin Mechanism of Resistance

Answer 9

Enzyme inactivation - Beta-Lactamse

Altered PCN binding Proteins (PBPs)

Question 10

What are the three clinical issues with Cephalosporins?

Answer 10

1) Most require dosing adjustment for renal failure (not ceftriaxone)
2) Resistance is increasing
3) Need double coverage for Pseudomonas

Question 11

General Structure for Carbapenems.

Answer 11

Beta-Lactam ring; Cabapenem Ring

Question 12

What are the Mechanisms of Resistance for Carbapenems?

Answer 12

Pseudomonas has shown altered permability to Imipenem.

Antagonism has been seen when Imipenem is used with other Beta-Lactams due to increased Beta-Lactamase production

Question 13

Mechanism of Action for Monobactams

Answer 13

Binds to PBPs and therefore inhibits cell wall formation

Question 14

Mechanism of Action for Vancomycin

Answer 14

Inhibits bacterial cell wall synthesis at earlier step than the Beta-Lactams

Question 15

Oxazolidinoe MOA

Answer 15

Protein Synthesis Inhibitor

Question 16

Streptogramin MOA

Answer 16

Protein Synthesis Inhibitor Combination

Question 17

Cyclic Lypopeptide MOA

Answer 17

Inhibits protein, RNA, DNA synthesis by depolarizing bacterial membranes

Question 18

Lipoglycopeptide MOA

Answer 18

Inhibits bacterial cell wall synthesis

Question 19

Glycylcycline MOA

Answer 19

Inhibits protein synthesis (semi-synthetic minocycline derivative)

Question 20

Fluoroquinolone General Structure

Answer 20

3-carboxy-6-fluoroquinolone ring with a Piperazine ring

Question 21

Fluoroquinolone MOA

Answer 21

Inhibits DNA replication in bacteria.

Question 22

Fluoroquinolone mechanisms of resistance

Answer 22

Efflux Pump; Gene mutations; Permeability