Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Respiratory 2 > 30S Protein Synthesis Inhibitors - Fitzpatrick > Flashcards

30S Protein Synthesis Inhibitors - Fitzpatrick Flashcards

1
Q

2 groups of 30S inhibitors

A

Aminoglycosides

Tetracyclines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Most commonly used Aminoglycoside

What organisms? Especially if they…

A

Gentamicin

Gram (-) aerobes (E. coli, Enterobacter, Serratia, Klebsiella, Tularemia)
- Especially those resistant to other safer antimicrobials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Tobramycin - clinical use

A

Pseudomonas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Amikacin - clinical use

A

Gentamicin-resistant organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Brucellosis - clinical treatment

A

Gentamicin + doxycycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Tularemia - clinical treatment

A

Gentamicin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Yersinia pestis (plague) - clinical treatment

A

Streptomycin + doxycycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Pseudomonas - clinical treatment

A

Tobramycin + Piperacillin/Ticarcillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Klebsiella - clinical treatment

A

Gentamycin + Piperacillin/Ticarcillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

While Gram (-) is typically the indication for Aminoglycosides, they may also be used synergistically with what else for what Gram (+) diseases?

A

W/ beta-lactams for Strep/Enterococcal endocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why are Aminoglycosides good for Gram (-) infections?

A

Highly polar, water-soluble structure allows for good passage through PORINS in outer membrane of Gram (-)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why are Aminoglycosides good for Gram (-) AEROBES only?

A

Enters Gram (-) aerobes through an O2-dependent channel in the INNER membrane. Anaerobes don’t have this channel, thus they are resistant to Aminoglycosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Are Aminoglycosides bacteriostatic or bacteriocidal? Explain.

A

Bacteriocidal - cause ribosome (via 30S subunit) to mis-read the mRNA and add a wrong amino acid, resulting in deficient proteins and DEATH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How might you be resistant to Aminoglycosides? (4)

A
  • Depletion/deficit of porins (multi-drug resistance)
  • Anaerobes or anaerobic environment
  • Enzymatic alteration of drug (acetyl, phosphoryl., adenyl)
  • 30S ribosome mutation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Examples of anaerobic bacteria resistant to Aminoglycosides

A
  • Clostridia
  • Actinomyces
  • Bacteroides
  • C. diff.
  • Fusobacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Aminoglycosides, if given too much, will accumulate in which 2 places?

Thus, what are 2 adverse effects of aminoglycosides?

A
  • Kidney —> nephrotoxicity

- Perilymph (ear) —> ototoxicity

17
Q

How to prevent adverse effects of Aminoglycosides?

A

Dose such that serum levels reach zero by the end of each day, thus preventing the development of a new steady state level that is GREATER THAN zero

18
Q

How are Aminoglycosides excreted?

A

100% via kidneys (b/c so polar)

19
Q

Who is a contraindication for Aminoglycoside use?

A

Perinatal or fetuses (hearing loss)

20
Q

What is the 3rd adverse effect of Aminoglycosides besides nephrotoxicity and ototoxicity?

What condition may be a contraindication then?

A

Neuromuscular blockade (nAChRs)

Myasthenia gravis

21
Q

Treatment for Aminoglycoside-induced neuromuscular blockade

A

Neostigmine or ventilator

22
Q

Tetracyclines - drugs (5)

A
  • Tetracycline
  • Minocycline
  • Doxycycline
  • Tigecycline
23
Q

Most commonly used Tetracycline

A

Doxycycline

24
Q

Characteristics of Doxycycline to remember (3)

A
  • Highly potent
  • PARENTERAL
  • Good w/ renal impairment
25
Q

Minocycline - best for what?

A

Meningococcal CARRIER STATE (CNS)

26
Q

Tigecycline - best for what?

A

MRSA

27
Q

Clinical indications for Doxycycline (6)

A
  • MYCOPLASMA PNEUMONIA (important in this section)
  • Rickettsia (RMSF, Q fever, Typhus)
  • Borrelia (Lyme disease)
  • Chlamydia (STD)
  • Psittacosis pneumonia
  • Vibrio (Cholera)
28
Q

Tetracyclines are used together with Aminoglycosides for which infections? (3)

A
  • Brucellosis (cows) - Gentamycin + Doxycycline
  • Tularemia (rabbits) - Gentamycin or Tetracycline
  • Plague (rats) - Streptomycin + Doxycycline
29
Q

How is MoA of Tetracyclines different from Aminoglycosides?

A
  • Bacteriostatic
  • Bind to 30S and prevent tRNA binding to mRNA
  • Inhibits RATE of protein synthesis
30
Q

2 mechanisms of resistance to Tetracyclines

A
  • EFFLUX PUMPS (pump drug out of bacteria)

- Ribosome mutation (inhibits 30S binding to drug)

31
Q

Adverse effects of Tetracyclines

A
  • Accumulate and stain in calcified tissues (bone, teeth)
  • Fatty liver (in pregnancy) –> hepatitis
  • GI superinfections (after eliminated gut microflora)
32
Q

A patient is on a Tetracycline for a gram (-) infection of some kind. What should NOT be taken w/ these drugs?

A

Calcium supplements or Antacids containing Ca++/Mg++

Tetracyclines chelate Ca/Mg –> stain teeth and bone

33
Q

A pregnant woman needs an antibiotic for a gram (-) infection, and the doctor suggests a Tetracycline. Is this a good choice? Why or why not?

A

NO - in pregnancy, the Tetracyclines alter metabolism in the mitochondria of the liver, INCREASING lipid production, causing FATTY LIVER –> fatal hepatitis

34
Q

A patient in on a Tetracycline for an abnormal pneumonia. Later, they develop severe pain in the gut and black stool. Explain.

A

Tetracyclines kill commensal enteric bacteria –> Clostridium difficile thrives –> PSEUDOMEMBRANOUS COLITIS

35
Q

Tigecycline has additional activity against which organisms? (NOT ON EXAM)

A

MRSA, VRE

Respiratory 2 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions