Lecture 3 Clinda/Tetra/Chlorem

Question 1

Clindamycin binds the ___ part of the ____ ribosome, inhibiting protein synthesis.

Answer 1

23s RNA; 50S

Question 2

Clindamycin is used for ___ gram + cocci and _____ gram - bacilli

Answer 2

aerobic; anaerobic

Question 3

Clindamycin is effective in treating lung abscesses and aspiration pneumonia caused by _____ and _____

Answer 3

bacteroides, fusobacterium

Question 4

Clindamycin is/is not effective against MRSA

Answer 4

is effective

Question 5

Clindamycin adminstered IV with _____ and _____ is used to treat AIDS patients with encephalitis caused by _____

Answer 5

pryimethamine, leucovorin;

Toxoplasma gondii

Question 6

Clindamycin is extensively metbaolized by ____ enzymes in the liver to _____ metabolites

Answer 6

CYP450;

inactive

Question 7

Side effects of clindamycin:

_____ ______ and _____ _____caused by C. Diff overgrowth, fever, and rash

Answer 7

Psuedomembranous Colitis, toxic megacolon

Question 8

Tetracyclines form stable ____ with ____ metal ions such as Ca, Al, Cu, and Mg

Answer 8

chelates; polyvalent

Question 9

The chelates made by tetracyclines and polyvalent metals are soluble/insoluble

Answer 9

insoluble

Question 10

Things to avoid when taking tetracyclines (3):

Answer 10

Calcium rich food
antacids
hematinics

Question 11

Tetracyclines chelate calcium during formation of ____. This turns them a ____ color, which becomes worse over time due to _____

Answer 11

teeth; brown/gray;

photo-oxidation

Question 12

Tetracyclines should be administered via injection with ___ and buffered to an ____ pH to decrease pain caused by the insoluble chelates

Answer 12

EDTA; acidic

Question 13

The epimer form of tetracycline, ______ is ______

Answer 13

epitetracycline; inactive

Question 14

The ___ carbon has a ____ group; it has an antiperiplanar relationship with the adjacent carbon’s proton, setting it up for elimination

Answer 14

C6; hydroxyl

Question 15

The metabolite formed via dehydration of tetracycline is _____. It is inactive and ____.

Answer 15

4-epianhydrotetracycline;

toxic

Question 16

4-epianhydrotetracycline can cause fatal ____ syndrome, which is due to decreased re-absorption in the _____

Answer 16

fanconi; PCT

Question 17

____ and ____ are tetracyclines with no C6 ___ group and thus cannot form the toxic metabolite

Answer 17

Minocycline; Doxycycline; OH

Question 18

Mechanism of action via tetracyclines:

Bind the ____ ribosome, blocking attachment of the tRNA to the ____ site, preventing _____

Answer 18

30S; A; translation

Question 19

Specifically, tetracyclines inhibit the ______ interaction

Answer 19

codon/anti-codon

Question 20

The most common use of Tetra- is for ____. They also remain the treatment of choice for infections caused by ____ and ____ due to their intracellular accumulation

Answer 20

acne; chlamydia, Rickettsia

Question 21

Tetracyclines treat infections caused from the “Great outdoors” (aka zoonotics), such as :

Answer 21

Lyme disease**
brucellosis**
Plauge
Tularemia
Q-fever

Question 22

Demeclocycline has a secondary ___ group at the C6 instead of the tertiary hydroxyl group. Its most stable intermediate is the ___ cation intermediate

Answer 22

hydroxyl

tertiary

Question 23

Minocycline has no _____ OH group; and therefore no toxic metabolites. It has especially high ___ bioavailability

Answer 23

C6;

oral

Question 24

Notably, ____ has vestibular toxicities such as vertigo and nausea

Answer 24

minocycline

Question 25

____ is used as prophylaxis for gum disease

Answer 25

minocycline

Question 26

_____ is the most hydrophillic tetracycline and used used along with _____ in eye drops

Answer 26

Oxytetracycline;

polymyxin B sulfate

Question 27

Doxycycline has a ____ half-life relative to the other tetracyclines

Answer 27

long; permits once a day dosing

Question 28

Chloramphenicol:

Binds the ____ ribosomal subunit, inhibiting _____ _____ activity

Answer 28

50s; peptidyl transferase

Question 29

Chloramphenicol blocks peptide formation between the ___ and ___ site

Answer 29

P , A

Question 30

Chloramphenicol is usually administered as chloramphenicol ____ _____, which is ____ in the liver

Answer 30

sodium succinate; hydrolyzed

Question 31

Resistance to chloramphenicol:

1. ____ membrane permeability
2. mutation of the _____

Answer 31

reduced; 50s ribosome

Question 32

Resistance to chloramphenicol:

Elaboration of chloramphenicol ________, which ______ one or both OH groups, forming non-reactive metabolites

Answer 32

acyltransferase

acylates

Question 33

_____ anemia is a rare but serious side effect of chloramphenicol. More common is _____ anemia, which occurs predictably at a cumulative dose of ___

Answer 33

aplastic;

reversible; 20

Question 34

Babies don’t have mature ______. Thus, chloramphenicol can cause _____ in infants

Answer 34

glucuronyl transferase;

gray baby syndrome