Tetracyclines

Question 1

tetracycline class

Answer 1

Tetracycline
demeclocycline
doxycycline
minocycline
tegacycline

Question 2

short acting tetracycline

Answer 2

6-8 h

tetracycline

Question 3

intermediate acting tetracycline

Answer 3

12h

demeclocycline

Question 4

long acting tetracycline

Answer 4

16-18 h
doxycycline
minocycline

Question 5

Glycycycline

Answer 5

36h

tegacycline

Question 6

Mechanism of action of tetracyclines

Answer 6

bacterioSTATIC (can antagonize cell wall inhibitor)

bind to 30S su - block trna binding to acceptor site

Question 7

spectrum of tetras

Answer 7

gram + - Aerobic anaerobic and some parasites

Question 8

main mode of resistance of tetras

Answer 8

Efflux pump

Question 9

tetras are contraindicated in

2

Answer 9

someone with reduced hepatic function (bc they accumulate in the liver)

pregnant and kids

Question 10

why are tetracyclines C/I in pregos and kids less than 8

Answer 10

they bind to newly formed calcium

• fetal deformities
• teeth deformities/ discoloration

stunted growth and deformities in kids

Question 11

what tetras are safe to give to someone with reduced renal function

Answer 11

doxycycline

tegacycline

Question 12

kinetics of tetracyclines
absorption
what should you avoid

Answer 12

doxycylcline and minocycline have greatest oral absorption

should avoid Dairy products(Ca), Mg Fe
- bc it can chelate

Question 13

side effects of tetracyclines

Answer 13

NVD
liver toxicity 
photosensitization - due to conjugated ring system
Fanconi syndrome 
super infections

Question 14

side effects specific to minocycline

Answer 14

Vestibular problems- bc it accumulates in inner ear endolymph
pseudotumor cerebri- benign inter cranial pressure increase

Question 15

Fanconi syndrome

Answer 15

due to consuming EXPIRED tetracyclines

it damages the proximal tubule- glucose in urine

Question 16

Which bacteria are intracellular

Answer 16

chlamydia
legionella
mycoplasma
ureoplasma

Question 17

which antibiotics can tx intracellular bacteria

Answer 17

tetracyclines
macrolides
fluoroquinolones

Question 18

which tetracycline most prescribed

Answer 18

doxycycline

Question 19

Doxycycline

DOC

Answer 19

• Ricketsia (typhus RMSF)
• Chlamydias (pscitaci, trachomatis)
• Atypical pneumonias (mycoplasma, chlamydial pneumonia)
• Tularemia, plague, Brucellosis
• Ureoplasma
• Cholera
• Donovanosis

Question 20

Doxycycline

backup for?

Answer 20

lyme disease (PNC)
syphilys/ leptospirosis (PNC)
C. perfingens (PNC)
Chancroid ( Ceftriaxone)

Question 21

why is doxycycline used to tx certain STIS

which ones

Answer 21

Bc it accumulates in the genitals
tx
-  Donovanosis (Klebsiella gran)
- Lymphogranuloma Verenereum ( Chlamydia T)
- Chancroid ( H. Ducreyi )

Question 22

Minocycline used used to TX?

its also better at tx

Answer 22

CARRIER state of N. Meningiditis
- bc it accumulates in saliva and tears

also better at Tx nocardia infections and acne

Question 23

Routes for tetracyclines

Answer 23

Tetracycline po
demeclocycline po
doxycycline po
minocycline po 
tegacycline  IV*

Question 24

Tygecycline use

Answer 24

increased activity against Tetracycline resistant microorganisms 
MRSA
VRSA
VISA
MRSE
VRE
\+ bacteroides