L6 Cushman

Question 1

T or F:
lincomycin has antibiotic activity

Answer 1

true but not used bc tox

Question 2

clindamycin MOA

Answer 2

inhibit protein synthesis by binding to 50S

Question 3

T or F:
there is no cross-resistance b/w clindamycin and erythromycin

Answer 3

F, there is

Question 4

Clindamycin effective against _____

Answer 4

AErobic GP Cocci
ANaerobic GN bacilli
(both most common morphologies)

Question 5

T or F:
Clindamycin can treat MRSA

Answer 5

true

Question 6

life threatening toxicity of clindamycin

Answer 6

pseudomembranous colitis

Question 7

clindamycin dosage forms

Answer 7

IV, topical foams, topical solutions, capsules, suspensions

Question 8

how is clindamycin metabolized

Answer 8

by cyp p450 enzymes in the liver

Question 9

T or F:
Clindamycin penetrates the CSF with ease

Answer 9

true actually

Question 10

two treatment options for pseudomembranous colitis from clindamycin

Answer 10

metronidazole or vancomycin

Question 11

T or F:
tetracycline is broad spectrum

Answer 11

true

Question 12

what is the relationship between metal ions and tetracyclines

Answer 12

tetracyclines form stable chelates with metal ions

Question 13

dont give tetracyclines with what

Answer 13

milk, food w/ calcium, tums, hema-anything

Question 14

if you HAVE to have concomitant therapy with tetracyclines and metals cant be avoided what do you do

Answer 14

metal 1 hour before OR 2 hours after to stop chelation

Question 15

what weird thing can tetracyclines cause if given to not-fully-developed people

Answer 15

permanently brown or grey teeth since they chelate calcium during tooth formation

Question 16

T or F:
you can give tetracyclines during pregnancy

Answer 16

true, but avoid after 4th month

Question 17

how do old tetracyclines lose half their potency

Answer 17

epimerization

Question 18

Epimerization is _____ in the solid state and ______ in solution at ph4

Answer 18

slow, rapid

Question 19

where can dehydration occur in tetracyclines

Answer 19

benzylic hydroxyl group at C-6

Question 20

dehydration of tetracyclines produces a toxic metabolite, what is it called and what can it produce?

Answer 20

4-epianhydrotetracycline, Falconi-like syndrome that can be fatal

Question 21

which tetracyclines are completely free of a dehydration reaction and why does this happen?

Answer 21

Doxycycline, Minocycline, and tigecycline they lack a C-6 hydroxyl group

Question 22

When do tetracyclines undergo cleavage

Answer 22

pH values over 8.5

Question 23

Tetracyclines MOA

Answer 23

bind to 30S ribosomal subunit and inhibit bacterial protein synthesis by blocking attachment of the aminoacyl-tRNA to the A SITE of ribosome, this terminates peptide chain growth

Question 24

T or F:
tetracycline binding sites overlap with erythromycin binding sites

Answer 24

false

Question 25

how many different locations on the small ribosomal subunit do tetracyclines bind to

Answer 25

6

Question 26

T or F: tetracyclines are broad spectrum

Answer 26

true

Question 27

most common use of tetracyclines

Answer 27

acne

Question 28

tetracyclines also treatment of choice for infections cause by?

Answer 28

chlamydia

Question 29

Difference in structure between tetracycline and demeclocycline

Answer 29

demec has a secondary hydroxyl at C6 instead of tertiary, this makes it dehydrate slower because the cation intermediate is less stable (higher energy)

Question 30

"tetracycline of choice"

Answer 30

doxycycline

Question 31

Which tetracycline has a long half life that permits once a day dosing

Answer 31

doxycycline shit also sarecycline

Question 32

T or F: sarecycline can cause fetal harm to a pregnant woman

Answer 32

true

Question 33

why should sarecycline not be administered with oral retinoids

Answer 33

bc both can cause increased intracranial pressure

Question 34

sarecycline dosage reduction is recommended with what drug class

Answer 34

anticoagulants

Question 35

Chloramphenicol moa

Answer 35

binds reversibly to 50S, inhibits peptidyl transferase activity and blocks peptide bond formation between P and A site

Question 36

3 resistance mechs for chloramphenicol

Answer 36

1) reduced membrane permeability 2) mutation of 50S 3) elaboration of chloramphenicol acetyltransferase, acetylates hydroxy group(s) to form metabolites that do NOT bind 50S

Question 37

chloramphenicol metabolism

Answer 37

metabolized to glucuronide in the liver

Question 38

most serious toxicity of chloramphenicol

Answer 38

aplastic anemia, fatal, more likely with oral and lowest risk with eye drops

Question 39

T or F: chloramphenicol inhibits cyp p450

Answer 39

true

Question 40

T or F: chloramphenicol reaches CSF

Answer 40

true

Question 41

1st gen quinolones activity against?

Answer 41

GN

Question 42

what is different about 2nd gen quinolones

Answer 42

have a fluorine sub. at C6 and a heterocyclic ring at C7

Question 43

what is the most potent fluoroquinolone?

Answer 43

ciprofloxacin

Question 44

2nd gen quinolones have activity against

Answer 44

More activity against GP and still GN coverage

Question 45

3rd and 4th gen quinolones have activity against

Answer 45

more for GP than 1st and 2nd, still GN but not as much as ciprofloxacin

Question 46

what quinolone is considered the "last resort" due to its toxicities

Answer 46

moxifloxacin

Question 47

what gen is cipro

Answer 47

2nd

Question 48

what gen is levofloxacin

Answer 48

3rd/4th? (he doesnt actually say i think)

Question 49

used topically to treat impetigo A. Ciprofloxacin B. Levofloxacin C. Moxifloxacin D. Ozenoxacin

Answer 49

D

Question 50

Ozenoxacin precaution

Answer 50

overgrowth with non-susceptible bacteria and fungi

Question 51

general adverse effects for all quinolones (unique ones)

Answer 51

tendonitis, tendon rupture, peripheral neuropathy, CNS effects

Question 52

quinolone MOA

Answer 52

inhibition of DNA religation in the topo II-DNA complex

Question 53

UTIs A. Ciprofloxacin B. Levofloxacin C. Moxifloxacin D. Ozenoxacin

Answer 53

A

Question 54

Prostatitis A. Ciprofloxacin B. Levofloxacin C. Moxifloxacin D. Ofloxacin

Answer 54

A and D

Question 55

Shigellosis A. Ciprofloxacin B. Levofloxacin C. Moxifloxacin D. Ozenoxacin

Answer 55

A

Question 56

diabetic foot infections A. Ciprofloxacin B. Levofloxacin C. Moxifloxacin D. Ozenoxacin

Answer 56

A

Question 57

3 resistance mechs for fluoroquinolones

Answer 57

1) decreased cellular permeability 2) efflux pumps 3) mutation of target enzymes

Question 58

T or F: fluoroquinolones are readily absorbed orally

Answer 58

true

Question 59

T or F: all fluoroquinolones are widely distributed

Answer 59

true

Question 60

major inactive metabolite of quinolones

Answer 60

glucuronide at 3-carboxyl position

Question 61

why are fluoroquinolones not recommended for pts under 18?

Answer 61

they can damage growing cartilage and cause arthropathy

Question 62

which random ass quinolone has been associated with hyperglycemia and hypoglycemia in diabetic patients

Answer 62

gatifloxacin