Week 4 - Protein Synthesis Inhibitors Flashcards Preview

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Flashcards in Week 4 - Protein Synthesis Inhibitors Deck (51)
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1
Q

What are the inhibitors of the 30S subunit?

A

aminoglycosides and tetracycline

2
Q

What are the inhibitors of the 50S subunit?

A

linezolid, macrolides, chloramphenicol, clindamycin, quinupristin/dalfopristin

3
Q

What drugs inhibit initiation?

A

linezolid, aminoglycosides

4
Q

What drugs inhibit elongation?

A

aminoglycosides, tetracycline, macrolides, chloramphenicol, clindamycin, quinuspristin/dalfopristin

5
Q

What drugs inhibit termination?

A

aminoglycosides

6
Q

What drugs produce a side effect due to interference with mitochondrial ribosomes? What is this side effect?

A

drugs: linezolid, tetracycline, chloramphenicol

- bone marrow suppression is the side effect

7
Q

What drug binds the P-site on the 50S?

A

Linezolid

8
Q

How do aminoglycosides prevent mRNA synthesis?

A

bind to the 30S ribosome and freeze the initiation complex

9
Q

What is the mechanism of action for Linezolid?

A

bacteriostatic – binds 50S on the 23S rRNA to prevent formation of of the initiation complex

10
Q

What is the spectrum for linezolid?

A

Gram +, MRSA and Vanco-resistant Enterococci

11
Q

Adverse effects of linezolid:

A

bone marrow suppression, Serotonin Syndrome if taken with SSRI (hallucinations, increase heart beat, agitation, nausea) due to inhibition of monoamine oxidase

12
Q

What are the aminoglycosides?

A

gentamicin, amikacin, tobramycin, neomycin, streptomycin (GNATS)

13
Q

What is the mechanism of action for aminoglycosides?

A

bactericidal – prevent formation of initiation complex, cause misreading of mRNA, induces early termination

14
Q

Spectrum of aminoglycosides:

A

gram - aerobes because they need a lot of energy get into the cell, and anaerobes have no oxidative phosphorylation

15
Q

Why would you treat with a cell wall inhibitor and an aminoglycoside?

A

to treat an anaerobe, need to break down cell wall for easier time getting into cell

16
Q

What is the spectrum of amikacin?

A

broader because it is less susceptible to enzyme inactivation, can treat Pseudomonas

17
Q

What antibiotics are concentration-dependent killers?

A

aminoglycosides, fluoroquinolones

18
Q

What antibiotics are time-dependent killers?

A

beta-lactams and vanco

19
Q

Adverse effects of aminoglycosides:

A
tubular necrosis: nephrotoxicity (drug retained in renal cortex) , ototoxic, pregnancy class D (due to hearing loss) 
neomycin - can cause allergic rxn in triple antibiotics
20
Q

What drug is administered by IV?

A

aminoglycosides

*also excluded from CSF

21
Q

Mechanism of action for Tetracyclines:

A

bacteriostatic – bind 30S preventing attachment of aminoacyl-tRNA

22
Q

What drugs are tetracyclines?

A

tetracycline, doxycycline, minocycline

23
Q

What is the spectrum for tetracyclines?

A

broad, but resistance has led to treating only: B. burfdorferi, H. pylori, Mycoplasma pneumoniae

24
Q

Adverse effects for tetracyclines

A

forms chelates with metal ions - decreases absorption (don’t take with antacids)
GI irritation, photosensitivity, discolor teeth, inhibit bone growth in kids
-don’t give to preggo

25
Q

What drug would be used to treat Lyme’s disease?

A

doxycycline – can be effective for treating other tick borne disease at the same time

26
Q

What bacteria exhibits a persister phenotype that is tolerant to drugs?

A

B. burgdorferi (Lyme’s)

27
Q

Mechanism of action for chloramphenicol:

A

bacteriostatic – binds 50S, prevents peptide bond formation, peptidyltransferase can’t associate with AA substrate

28
Q

Spectrum for chloramphenicol:

A

extended, but limited use due to side effects

29
Q

Adverse effects of chloramphenicol:

A

Toxic, bone marrow suppression, aplastic anemia, Gray baby syndrome – don’t use for prego

30
Q

What is gray baby syndrome?

A

babies have decreased renal function, high levels of drug build up, leads to cardiovascular and respiratory collapse

31
Q

What are the macrolides?

A

erythromycin, azithromycin, clarithromycin

32
Q

Mechanism for macrolides

A

bacteriostatic – inhibit translocation by binding 23S rRNA of the 50S subunit

33
Q

Spectrum for macrolides:

A

broad coverage of respiratory pathogens, Chlamydia

34
Q

What would you use to treat Mycoplasma?

A

doxycycline, azithromycin, levofloxacin

no cell wall so no beta lactams

35
Q

Adverse effects for macrolides:

A

GI discomfort, hepatic failure, prolonged QT interval, inhibits action of Cyp450 enzymes
**clarithromycin - don’t give to prego

36
Q

Mechanism for Clindamycin

A

bacteriostatic – blocks translocation at 50S

37
Q

Spectrum for Clindamycin:

A

gram + including anaerobic, treats acne

38
Q

Adverse effects of clindamycin:

A

hypersensitivity, GI issues (blood in stool), Superinfection with C. diff

39
Q

What drugs are the streptogramins?

A

quinupristin/dalfopristin

40
Q

Mechanism for streptogramins

A

combo action is bactericidal for some organisms, bind 50S to inhibit translocation

41
Q

Spectrum for quinupristin/dalfopristin

A

should be reserved for infections caused by multiple drug-resistant Gram + bacteria

42
Q

Adverse effects for streptogramins:

A

arthralgias, myalgia (pain), inhibits Cyp450 enzymes, likely to have significant drug interactions

43
Q

What drugs will have increased efflux as the resistance mechanism?

A

Tetracyclines, macrolides, quinopristin/dalfopristin

44
Q

What drugs will have decreased uptake as the resistance mechanism?

A

aminoglycosides, chloramphenicol

45
Q

What drugs will have altered target as the resistance mechanism?

A

Linezolid, aminoglycosides, quinupristin/dalfopristin, tetracyclines

46
Q

What drugs will have enzymatic inactivation of drug as the resistance mechanism?

A

Aminoglycosides (amikacin most resistant), chloramphenicol, tetracyclines, macrolides, clindamycin, quinupristin/dalfopristin, metronidazole

47
Q

Drugs reserved fro MRSA and VRE

A

5th generation cephalosporin, vancomycin, daptomycin, quinupristrin/dalfopristin, linezolid

48
Q

Don’t use in newborns (can’t glucoronidate)

A

Chloramphenicol (Gray baby), Sulfonamides (Kernicterus jaundice)

49
Q

Don’t use in children

A

Tetracycline, Fluoroquinolones (arthropathy)

50
Q

Don’t use during pregnancy

A

Chloramphenicol, Sulfonamides, Tetracycline, Fluoroquinolones, Aminoglycosides, Clarithromycin

51
Q

Reserved for MRSA & VRE

A

5th gen. cephalosporins, vancomycin, daptomycin, quinipristin/dolfapristin, linezolid