FA Tetracyclines

Question 1

tetracyclines agents?

Answer 1

tetracycline; minocycline; doxycycline; demeclocycline

Question 2

p/os and i/v tetracyclines agents?

Answer 2

tetracycline; minocycline;

Question 3

only p/os tetracyclines agents?

Answer 3

doxycycline; demeclocycline

Question 4

Tetracyclines static or cidal?

Answer 4

static

Question 5

Tetracyclines
mechanism

Answer 5

Mechanism of action: bind 30S subunit → aminoacyl-tRNA is blocked from binding to ribosome acceptor site → inhibition of bacterial protein synthesis (bacteriostatic effect)

Question 6

Tetracyclines prevent binding of what structure?

Answer 6

prevents attachement of aminoacyl-tRNA

Question 7

Tetracyclines bbb penetration?

Answer 7

limited/poor

Question 8

Tetracyclines route of elimination?

Answer 8

Renal
Doxycycline: only gastrointestinal elimination (doxycycline is the only tetracycline that is not contraindicated in patients with renal failure)

Question 9

Tetracyclines. which one is not contraindicated in patients with renal failure?

Answer 9

doxycycline. fecal elimination

Question 10

Tetracyclines. what not dot use with p/os tetracyclines?

Answer 10

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.

Question 11

Tetracyclines. tick disease?

Answer 11

Against borrelia burgdorferi (laimo liga)

Question 12

Tetracyclines. what intracellular bacteria?

Answer 12

Intracellular bacteria, such as Rickettsia, Chlamydia, or Anaplasma (tetracyclines accumulate intracellularly and are, therefore, effective against intracellular pathogens)

Question 13

Tetracyclines. bacteria that lack a cell wall?

Answer 13

Bacteria that lack a cell wall (e.g, Mycoplasma pneumoniae, Ureaplasma)

Question 14

doxycycline against what community-acquired m/o?

Answer 14

against community-acquired MRSA (doxycycline)

Question 15

what other m/os treated with tetracyclines?

Answer 15

Other: Ehrlichia, Vibrio cholerae, Francisella tularensis
!!!!!Cutibacterium acnes (topical tetracycline is used to treat acne)

Question 16

Adverse of tetracyclines?

Answer 16

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.

Question 17

contraindications of tetracyclines?

Answer 17

Children < 8 years of age (except doxycycline)
Pregnant women
Breastfeeding women
Patients with renal failure (except doxycycline)
Cautious use in patients with hepatic dysfunction

Question 18

tetracyclines mechanism of resistance?

Answer 18

Mechanisms of resistance: Plasmid-encoded transport pumps increase efflux out of the bacterial cell and decrease uptake of tetracyclines.