FA Tetracyclines Flashcards
tetracyclines agents?
tetracycline; minocycline; doxycycline; demeclocycline
p/os and i/v tetracyclines agents?
tetracycline; minocycline;
only p/os tetracyclines agents?
doxycycline; demeclocycline
Tetracyclines static or cidal?
static
Tetracyclines
mechanism
Mechanism of action: bind 30S subunit → aminoacyl-tRNA is blocked from binding to ribosome acceptor site → inhibition of bacterial protein synthesis (bacteriostatic effect)
Tetracyclines prevent binding of what structure?
prevents attachement of aminoacyl-tRNA
Tetracyclines bbb penetration?
limited/poor
Tetracyclines route of elimination?
Renal
Doxycycline: only gastrointestinal elimination (doxycycline is the only tetracycline that is not contraindicated in patients with renal failure)
Tetracyclines. which one is not contraindicated in patients with renal failure?
doxycycline. fecal elimination
Tetracyclines. what not dot use with p/os tetracyclines?
Oral tetracyclines should not be taken with substances that contain large amounts of Ca2+, Mg2+, or Fe2+ (e.g., milk, antacids, iron supplements, respectively) because divalent cations inhibit the intestinal absorption of tetracyclines.
Tetracyclines. tick disease?
Against borrelia burgdorferi (laimo liga)
Tetracyclines. what intracellular bacteria?
Intracellular bacteria, such as Rickettsia, Chlamydia, or Anaplasma (tetracyclines accumulate intracellularly and are, therefore, effective against intracellular pathogens)
Tetracyclines. bacteria that lack a cell wall?
Bacteria that lack a cell wall (e.g, Mycoplasma pneumoniae, Ureaplasma)
doxycycline against what community-acquired m/o?
against community-acquired MRSA (doxycycline)
what other m/os treated with tetracyclines?
Other: Ehrlichia, Vibrio cholerae, Francisella tularensis
!!!!!Cutibacterium acnes (topical tetracycline is used to treat acne)
Adverse of tetracyclines?
Hepatotoxicity
Deposition in bones and teeth → inhibition of bone growth (in children) and discoloration of teeth
Damage to mucous membranes (e.g., esophagitis, GI upset)
Photosensitivity: drug or metabolite in the skin absorbs UV radiation → photochemical reaction → formation of free radicals → damage to cellular components → inflammation (sunburn-like).
Degraded tetracyclines are associated with Fanconi syndrome.
contraindications of tetracyclines?
Children < 8 years of age (except doxycycline)
Pregnant women
Breastfeeding women
Patients with renal failure (except doxycycline)
Cautious use in patients with hepatic dysfunction
tetracyclines mechanism of resistance?
Mechanisms of resistance: Plasmid-encoded transport pumps increase efflux out of the bacterial cell and decrease uptake of tetracyclines.
