Pharm - Protein Synth Inhibitors: Tetracyclines and glycylcyclines

Question 1

tetracyclines and glycylcyclines are bacteriostatic or cidal?

Answer 1

static

Question 2

macrolides are bacteriostatic or cidal?

Answer 2

static

Question 3

erythromycin is an examples of a……..

Answer 3

macrolide

Question 4

streptogramins are bacteriostatic or cidal?

Answer 4

cidal (in combo)

Question 5

cloramphenicol is bacteriostatic or cidal

Answer 5

static

Question 6

lincosamides are bacteriostatic or cidal

give an ex

Answer 6

clindamycin

static

Question 7

aminoglycosides are bacteriostatic or cidal

Answer 7

cidal

Question 8

oxazolidinones are bacteriostatic or cidal

Answer 8

static

Question 9

most of a bacterial ribosome consists of what?

Answer 9

RNA

Question 10

aminoglycosides act on what bacterial ribosome

Answer 10

30s

Question 11

tetracyclines and glycylcyclines act on what bacterial ribosome

Answer 11

30s

Question 12

____- and _____ are the only protein synthesis inhibitors that act on the 30s ribosome. all the others act on 50s

Answer 12

tetracyclines and glycylcyclines and aminoglycosides

Question 13

the 50s subunit is the ___ ribsosome

Answer 13

the larger ribosomal subunit

30s is the smol one

Question 14

name 3 glycylcylines

Answer 14

tigecycline
eravacycline
omadacycline

Question 15

why were the glycylcyclines made

Answer 15

are long acting (better pharmacokinetic profile) and have a better resistance profile than tetracyclines

Question 16

how do the glycylcyclines have a better resistance profile than the tetracyclines

Answer 16

their structure doesn’t allow for proper binding to the efflux pump

Question 17

tetracyclines are _____ spectrum ____ antibiotics that inhibit what?

Answer 17

broad spectrum bacteriostatic that inhibit protein synthesis

Question 18

briefly explain the MOA of tetracyclines

Answer 18

they reversibly bind to the 30s subunit of the bacterial ribosome

this blocks the binding ot the aminoacyl-tRNA to the acceptor (A) site on the mRNA-ribosome complex

Question 19

what is the aminoacyl-tRNA

Answer 19

the tRNA that brings the amino acid

Question 20

how do tetracyclines enter the bacteria

Answer 20

by passive diffusion and in part by active transport (energy dependent)

Question 21

true or false

tetracyclines are only active against gram negative bacteria

Answer 21

FALSE - broad spectrum
gram (+) and (-)

Question 22

what are tetracyclines NOT very active against

Answer 22

pseudomonas, neisseria, enterobacter

Question 23

3 methods of tetracycline resistance

Answer 23

1. decreased influx of the AB OR getting an efflux pathway
2. bacteria produce a protein that protects the ribosome - displaces the tetracycline from its 30s target
3. enzymatically inactivated

Question 24

name 3 different efllux pumps that bacteria can produce against tetracyclines

include what bacteria produce them and what they provide resistance to

Answer 24

Tet (AE) efflux pump - produced by gram negative species. provides resistance against tet,doxy, and mino - BUT NOT TIGECYCLINE

Tet (K) efflux pump - produced by staphylococci. provides resistance to tetracycline but NOT doxy, mino, or tigecycline

proteus and pseudomonas produce their own specific efflux pump that gives resistance to ALLL - tetracyclines and tigecycline

Question 25

as mentioned, a mechanism of resistance to tetracyclines is the production of a ribosomal protection protein name 2 of these proteins and what they are/aren't resistant to

Answer 25

tet(M) and tet(O) resistant to doxy, tet, and mino, BUT STILL SUSCEPTIBLE TO TIGECYCLINE therefore, tigecycline overcomes 2 resistance mechanisms

Question 26

what other antibiotic class has a similar resistance mechanism of protection proteins

Answer 26

fluoroquinolones --- QNR proteins

Question 27

how can the absorption of tetracyclines be impaired

Answer 27

when given with divalent and trivalent cations (like quinolones) do not give dairy products or antacids

Question 28

the oral absorption of most tetracyclines is......

Answer 28

incomplete

Question 29

how is tigecycline administered

Answer 29

NOT ABSORBED WELL -- only parenteral

Question 30

concern with tetracyclines

Answer 30

-cross placenta and excreted in breast milk -cause damage to growing bones and teeth!!!

Question 31

explain the DDIs of tetracyclines

Answer 31

there are a lot. many drugs like carbamezepime, phenytoim, barbiturates, and alcohol decrease the half life by 50% --- so need to increase dose

Question 32

______ is a substrate of CYP3A4, so there are many potential drug-drug interactions

Answer 32

eravacycline

Question 33

true or false tetracyclines have good activity against anaerobes

Answer 33

true (how to remember - they're used in acne)

Question 34

name 5 things in which tetracyclines are drug of choice

Answer 34

rickettsia borrelia mycoplasma pneumonia chlamydia some spirochetes

Question 35

true or false tetracyclines can be used for CAP

Answer 35

true

Question 36

can tetracyclines be used for MRSA

Answer 36

mild-moderate MRSA

Question 37

true or false tetracyclines can't be used in lyme disease

Answer 37

false - they can

Question 38

true or false tigecycline is broad spectrum bacteriostatic

Answer 38

true high potency against range of both gram (+) and (-)

Question 39

TRUE OR FALSE tigecycline is not active against MRSA

Answer 39

false - it is

Question 40

how is tigecycline administered and how eliminated

Answer 40

IV only eliminated through bile - no dose adjustment for renal insufficiency!

Question 41

eravacycline is a _________ tetracycline for _______

Answer 41

fluorinated complicated intrabdominal infections

Question 42

main adverse affects of all tetracyclines

Answer 42

GI -NVD(because broad) photosensitivity hepatoxicity nephrotoxicity discolor teeth and affect bone growth FANCONI SYNDROME (only for expired) --- sugars and electrolytes not reabsorbed back into the body

Question 43

can tetracyclines be used in pregnancy

Answer 43

NO - teratogenic

Question 44

true or false production of Tet(M) protein is a resistance mechanism against tigecycline

Answer 44

FALSE --- tigecycline is resistant to this mechanism

Question 45

chemically, what is tigecycline

Answer 45

a glycylcycline

Question 46

what does the extended structure of tigecycline allow for

Answer 46

resistance doesn't happen as much as tetracyclines

Question 47

true or false tigecycline is active against MRSA

Answer 47

true