Tetracyclines Flashcards
tetracycline class
Tetracycline demeclocycline doxycycline minocycline tegacycline
short acting tetracycline
6-8 h
tetracycline
intermediate acting tetracycline
12h
demeclocycline
long acting tetracycline
16-18 h
doxycycline
minocycline
Glycycycline
36h
tegacycline
Mechanism of action of tetracyclines
bacterioSTATIC (can antagonize cell wall inhibitor)
bind to 30S su - block trna binding to acceptor site
spectrum of tetras
gram + - Aerobic anaerobic and some parasites
main mode of resistance of tetras
Efflux pump
tetras are contraindicated in
2
someone with reduced hepatic function (bc they accumulate in the liver)
pregnant and kids
why are tetracyclines C/I in pregos and kids less than 8
they bind to newly formed calcium
- fetal deformities
- teeth deformities/ discoloration
stunted growth and deformities in kids
what tetras are safe to give to someone with reduced renal function
doxycycline
tegacycline
kinetics of tetracyclines
absorption
what should you avoid
doxycylcline and minocycline have greatest oral absorption
should avoid Dairy products(Ca), Mg Fe
- bc it can chelate
side effects of tetracyclines
NVD liver toxicity photosensitization - due to conjugated ring system Fanconi syndrome super infections
side effects specific to minocycline
Vestibular problems- bc it accumulates in inner ear endolymph
pseudotumor cerebri- benign inter cranial pressure increase
Fanconi syndrome
due to consuming EXPIRED tetracyclines
it damages the proximal tubule- glucose in urine
Which bacteria are intracellular
chlamydia
legionella
mycoplasma
ureoplasma
which antibiotics can tx intracellular bacteria
tetracyclines
macrolides
fluoroquinolones
which tetracycline most prescribed
doxycycline
Doxycycline
DOC
- Ricketsia (typhus RMSF)
- Chlamydias (pscitaci, trachomatis)
- Atypical pneumonias (mycoplasma, chlamydial pneumonia)
- Tularemia, plague, Brucellosis
- Ureoplasma
- Cholera
- Donovanosis
Doxycycline
backup for?
lyme disease (PNC)
syphilys/ leptospirosis (PNC)
C. perfingens (PNC)
Chancroid ( Ceftriaxone)
why is doxycycline used to tx certain STIS
which ones
Bc it accumulates in the genitals tx - Donovanosis (Klebsiella gran) - Lymphogranuloma Verenereum ( Chlamydia T) - Chancroid ( H. Ducreyi )
Minocycline used used to TX?
its also better at tx
CARRIER state of N. Meningiditis
- bc it accumulates in saliva and tears
also better at Tx nocardia infections and acne
Routes for tetracyclines
Tetracycline po demeclocycline po doxycycline po minocycline po tegacycline IV*
Tygecycline use
increased activity against Tetracycline resistant microorganisms MRSA VRSA VISA MRSE VRE \+ bacteroides
