Tetracyclines

Question 1

tetracyclines bind very strongly with divalent and trivalent metal ions to form ______________________ which can interfere with drug dissolution and bioavailability

Answer 1

insoluble complexes

Question 2

what happens with divalent cations orally?

Answer 2

chelate and prevent oral absorption

Question 3

how are tetracyclines eliminated?

Answer 3

renal and hepatic

Question 4

tetracyclines bind to the 30S ribosomal subunit. what does this do?

Answer 4

inhibits protein synthesis
prevents addition of amino acids to a growing peptide chain

Question 5

what tetracyclines are more lipid soluble and cross most barriers, including the blood brain barrier?

Answer 5

doxycycline and minocycline

Question 6

how common is cross-resistance within tetracyclines?

Answer 6

common

Question 7

what are the common tetracycline agents?

Answer 7

chlortetracycline
oxytetracycline
tetracycline
doxycycline

Question 8

what is the spectrum like with tetracyclines?

Answer 8

one of broadest
great deal of resistance exists for many common bacterial pathogens

Question 9

what is the primary injectable tetracycline in veterinary medicine?

Answer 9

oxytetracycline

Question 10

what is the preferred tetracycline in small animal?

Answer 10

doxycycline

Question 11

what is the drug of choice for tick-borne disease and Leptospirosis?

Answer 11

doxycycline

Question 12

what is a common adverse effect of tetracyclines?

Answer 12

gastrointestinal floral disruption

Question 13

why is doxycycline used to treat Leptospirosis?

Answer 13

to clear renal carrier state

Question 14

what is a unique adverse effect of doxycycline?

Answer 14

hepatotoxicity

Question 15

sudden collapse following _________________________ is one adverse effect of tetracyclines

Answer 15

rapid IV administration

Question 16

what can tablets of doxycycline cause in cats?

Answer 16

esophageal ulcers/strictures

Question 17

who should you not use IV doxycycline in?

Answer 17

equine: cardiac arrhythmias, collapse, death

Question 18

what things are divalent cations?

Answer 18

dairy products and antacids

Question 19

what decreases the bioavailability of tetracyclines?

Answer 19

food: 60% decrease

Question 20

what is the distribution of tetracyclines?

Answer 20

vary by agent

Question 21

what is the distribution of doxycyclines and minocycline?

Answer 21

lipid soluble: cross most barriers, including blood brain barrier

Question 22

what is resistance of tetracyclines mediated by?

Answer 22

plasmids

Question 23

what determines the efficacy of tetracyclines?

Answer 23

time-dependent maybe

Question 24

are tetracyclines bacteriostatic or bactericidal?

Answer 24

bacteriostatic

Question 25

what is a less commonly used tetracycline?

Answer 25

minocycline

Question 26

is there a lot of resistance with tetracyclines?

Answer 26

yes

Question 27

what is the four quadrant coverage of tetracyclines?

Answer 27

E. coli: -
Staphylococcus: *
Streptococcus: *
anaerobes: *

Question 28

what do tetracyclines work for that are not in the four quadrants?

Answer 28

Chlamydia
Rickettsia
Leptospirosis
Mycoplasma

Question 29

what is the distribution like of doxycylcine?

Answer 29

more lipid soluble: better barrier penetration, including prostate and blood brain barrier

Question 30

what drug is used during initial Leptospirosis stabilization?

Answer 30

ampicillin because it is cheaper than doxycycline

Question 31

does ampicillin or doxycycline have better tissue penetration?

Answer 31

doxycycline

Question 32

what do all of the tetracyclines except for doxycycline cause as an adverse effect?

Answer 32

staining of teeth from in utero exposure or exposure prior to eruption of adult teeth

Question 33

what is a unique adverse effect of tetracyclines for cats?

Answer 33

esophageal strictures/ulcers
tablets: doxycycline

Question 34

what drug is not safe to use IV in horses?

Answer 34

doxycycline
cardiac arrhythmias, collapse, death