Antibacterial Agents 3: Protein Synthesis Inhibitors

Question 1

What are the main Protein Synthesis inhibitors?

Answer 1

1. Macrolides (-Thromycins)
2. Tetracyiclines (including Doxycycline)
3. Clindamycin
4. Aminoglycosides (linezolid)

Question 2

Are Protein Synthesis inhibitors more lipid soluble or water soluble? Why is this important?

Answer 2

Lipid

Lipid soluble drugs tend to be metabolized.

Question 3

Which DQCRIMES drugs are Non renal eliminated (also non hepatotoxic)

Answer 3

Doxy and Clindamycin

Question 4

Which Erythromycin like drug (from DQCRIMES) does not inhibit P450?

Answer 4

Azithromycin is A-OKAY

Question 5

Which DQCRIMES inhibit P450?

Answer 5

Quinolones

Erythromycin like drugs (Macrolides)except Azithromycin

Question 6

Protein Synthesis inhibitors generally target the __________ and are (bactericidal or bacteriostatic drugs)

Answer 6

Target Mitochondrial subunits (do not need to know 30 vs 50s)

They are bacteriostatic (except aminoglycosides)

Question 7

Which of the following mechanisms of resistance is true of macrolides?

1. Inc Efflux
2. Dec entry
3. Ezymatic inactivation
4. Altered target

Answer 7

Altered Target

S. Pneumonia and H. Influenza change the 50s binding site.

Question 8

How are macrolides administered?

Answer 8

Orally

Question 9

T/F Azythromycin is metabolized in the liver.

Answer 9

False, It is NOT metabolized but instead excreted in the biliary pathway.

Question 10

One large single dose of azithromycin can cover

Answer 10

Atypical Chlamydia.

Question 11

What is the major advantage of Clarithromycin?

Answer 11

Greater duration of Activity.

Question 12

What is the mechanism of resistance for Tetracyclines?

1. Inc Efflux
2. Dec entry
3. Ezymatic inactivation
4. Altered target

Answer 12

1. Inc Efflux

MDR transporters move drug OUT OF CELL

Question 13

True or False: Doxycycline is absorbed better than tetracycline AND may penetrate placental tissue.

Answer 13

True

Question 14

T/F: All protein inhibitors can treat MSSA and MRSA.

Answer 14

False:

Macrolides, doxycycline and Clindamycin can.
Aminoglycosides CANT

Question 15

Gonorrhea frequently “travels” with which other bacteria?

Answer 15

Atypical Chlamydia.

Question 16

Which protein synthesis inhibitors treat Atypical Chlamydia and Mycoplasma?

Answer 16

Macrolides(-thromycins) and Doxycyclin.

Question 17

Which drugs have a broad enough coverage to be able to cause superinfections (C. Diff)?

Answer 17

1. Clindamycin** Important
   has no action against C.diff
2. 3rd Gen Cephalo
3. Amox/Clav
4. Flouroquinones

Question 18

Which drugs can treat C. Diff?

Answer 18

1. Vancomycin

2. Metronidazole (DNA inhibitor)

Question 19

Which drug class can cause a fungal (candida) overgrowth?

Answer 19

Tetracyclines

Question 20

How does clindamycin work?

Answer 20

It is a static protein synthesis inhibitor (he said this was the answer to a TQ)

Question 21

Which PSIs best treat B. Fragilis?

Answer 21

Clindamycin***most important

Tetracycline

Question 22

What are some of the common adverse reactions for clindamycin?

Answer 22

Nausea, Diarrhea (c. diff), Skin rashes.

Question 23

Aminoglycosides are ONLY effective against __________ (bacteria type)

Answer 23

Gram - Rods

E. Coli and Pseudomonas

Question 24

T or F:

Amino glycosides bind reversibly to ribosomal subunits.

Answer 24

False

They bind IRREVERSIBLY to ribosomes. This is why they are bactericidal.

Question 25

How are Aminoglycosides administered?

Answer 25

IM injection.

Question 26

Where do aminoglycosides tend to accumulate in the body?

Answer 26

1. Renal Cortex (nephrotoxicity)

2. Inner Ear (ototoxicity)