Brainscape's Knowledge GenomeTM

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


See full index

ID Pharm > Protein Synthesis Inhibitors > Flashcards

Protein Synthesis Inhibitors Flashcards

1
Q

Name 4 mechanisms of resistance

A

Reduced drug accumulation = efflux pumps
Alteration of target = ribosome protective proteins
Metabolic pathway = change how they work
Drug inactivation = beta-lactamase (enzymes)

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

What does it mean to methicillin resistant?

A

Methicillin is an Abx that is stable to b-lactamase, so if the microorganism is resistant to methicillin it is dangerous because this is something that should normally work = MRSA

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

Why is Mycoplasma Pneumoniae resistant to penicillins and cephalosporins?

A

Because it lacks a peptidoglycan cell wall, BUT DOES NOT produce b-lactamase
Since PCNS and Cephs are peptidoglycan cell wall synthesis inhibitors, they have no effect on Mycoplasma because it lacks a peptidoglycan cell wall

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

What is a protein synthesis inhibitor?

A

A substance that stops or slows the growth or proliferation of cells by disrupting the processes that lead directly to the generation of new proteins

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

How do protein synthesis inhibitors work? Why would you use them?

A

Target the bacterial ribosome w/in the cell

Use when you cannot relay on cell wall synthesis inhibitors

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

What is the bacterial ribosome made of?

A

70S ribosome
50S large subunit
30S small subunit

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

Which Abx affect the 30S subunit

A

Buy AT 30
Aminoglycosides: gentimicin, neomycin, streptomycin
Tetracyclines: Doxycycline, Minocyclin, Tetracyclin
Spectinomycin

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

Which Abx affect the 50S subunit

A 
Macrolides: Azithromycin, Clarithromycin, Erythromycin
Ketolide: telithromycin (Ketek)
Chloramphenicol
Clindamycin - Lincomide
Quinupristin-dalfopristin (Synercid)
Mupirocin (Bactroban)
Linezolid (Zyvox)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Aminoglycoside MOA:

A

affinity for 30S ribosome

narrow therapeutic to toxic ratio

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

How do aminoglycosides gain entry into the cell?

A

Disrupt Mg and Ca bridges between lipopolysaccharide moieties
Transported across membrane in energy-dependent manner - inhibited by divalent cations, increased osmolality, acidic pH and an anaerobic activity

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

Are Aminoglycosides bacteriostatic or -cidal?

A

Bacteriocidal - the only protein synthesis inhibitors that are bacteriocidal

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

How are aminoglycosides often prescribed?

A

Rarely as monotherapy due to resistance

Rx with PCNs for broad empiric coverage - synergism allows AG Gm+ coverage

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

When can AGs be used for monotherapy?

A

Tularemia
Plague
Uncomplicated, Gm -, drug resistant UTIs

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

AG Mechanism of Resistance

A

AG modifying enzymes and/or alterations to ribosomal 30S binding sites
Enzymes often plasmid borne
Diminished uptake due to mutations in electrochemical gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

AG Spectrum of Activity

A 
Aerobic, Gm- bacteria
Enterobacteria
Pseudomonas
Gm + staph/strep with PCN synergism
NO anaerobic coverage
Below the belt infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

AG PK

A

Good distribution: low protein-binding and water soluble
Does not cross BBB or bronchial secretions - dislikes low pH
Excreted virtually unchanged in urine
Given IV or IM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

AG clinical indications

A

external otitis media - topical (pseudomas)
chronic pulm infx in CF - inhaled tobramycin
Gm - bacillary meningitis - intrathecal or intraventricular
Peritoneal dialysis peritonitis - intraperitoneal
Prosthetic joint infx - impregnated cement formulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

AG toxicity

A

Nephrotoxicity - reversible

Ototoxicity - nonreversible - tinnitus, vertigo, ataxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Name the AGs -NASTG

A 
Gentamicin
Tobramycin
Neomycin
Amikacin (Amikin)
Streptomycin
NASTG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Name the Tetracyclines - DTMD

A 
Doxycycline
Tetracycline
Minocycline
Demeclocycline
DTMD (death to microbe demons)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Tetracycline MOA

A

binds to 30S subunit - bacteriostatic

blocks access of tRNA o mRNA-ribosome complex (A site), inhibiting bacterial protein synthesis

22
Q

Tetracycline SOA

A

Broad spectrum against Gm + and Gm - anaerobes
Mycoplasma, rickettsia, legionella, spirochetes, chlamydia
STI, atypical pneumonia, chronic bronchitis, acne, alternative for sinusitis and acute prostatitis

23
Q

Tetracycline Resistance

A

If resistant to one Tetracycline, will be resistant to all
Cell develops efflux pumps
Forms ribosomal protection proteins

24
Q

Tetracycline PK

A

Oral, IV, IM (not recommended)
Absorption: adequate but incomplete orally - do not take with dairy (Ca, Al, Mg, Fe will bind) - less with doxy
Distribution: concentrates in liver, kidney, spleen, skin, tissues undergoing calcification (teeth and bones)
insufficient in CNS
Crosses placental barrier

25
Q

Tetracycline Elimination

A

concentrates in liver where it is metabolized and conjugated
Released in bile
Reabsorbed in intestine to enter urine via glom filtration
Doxy exception: metabolite preferentially excreted via bile into feces = can use in renally compromised patients

26
Q

Tetracycline AE

A

Teeth staining, deposits in bone causing hypoplasia and growth stunting
GI discomfort with dairy - take with other food
Phototoxicity
Hepatotoxic
Vestibular problems: dizzy, N/V with minocycline

27
Q

Tetracycline CI

A

pregnant women, lactation
Children < 8
Renal impairment (except doxy)
Liver function impairment

28
Q

What is doxy a DOC for?

A

mycoplasma pneumoniae, chlamydia, rickettsial (RMSF), and lyme

Chlamydia, Q fever, bubonic plague, cat scratch fever, RMSF, lyme, PID

29
Q

Name the macrolides - ACET

A 
erythromycin
azithromycin (Zithromax)
clarithromycin (Biaxin) - good for bartonella (Cat Scratch Fever)
Ketek - telithromycin
ACET
30
Q

Macrolide MOA

A

Binds irreversibly to 50S subunit
Inhibits translocation steps of protein synthesis
Bacteriostatic

31
Q

Erythromycin SOA

A 
Same as PCN - use in allergy
Chlamydia, Mycoplasma, legionella 
Gm - and Gm+ coverage - Step p., GABHS
Strep, CAP, acne
Safe in pregnancy
SE: poor GI tolerance
32
Q

Azithromycin SOA

A

Less active against strep and staph than eryth
Respiratory infx: H. flu, M. cat, CAP, ABECB - anti-inflam
DOC Chlamydia

33
Q

Clarithromycin SOA

A

Similar to erythromycin + H. flu
CAP, legionella, H. pylori
Sinusitis, bronchitis, ABECB

34
Q

Macrolide Resistance

A

Most strains of staph are erythromycin resistant
Changes to rRNA prevent macrolide binding
Altered macrolide binding site on ribosomal RNA = high resistance
Active macrolide efflux pumps

35
Q

Macrolide PK (A&D)

A

Eryth must be enteric coated - readily absorbed
Azith and Clarith = stable in stomach acid, readily absorbed
Distributed well in tissues except CSF

36
Q

Macrolide PK (M&E)

A

Eryth: CYP450 metabolized - concentrated in bile
Clarith: metabolized by liver - COLCHICINE - eliminated by kidneys and liver (adjust in renal patients)
Azith: not CYP metab, long half-life - few drug interactions
Concentrated in bile

37
Q

Macrolide AE

A

GI distress - especially with erythromycin
QT prolongation - mainly erythromycin - get EKG
Hepatotoxicity with ketek (telithromycin)

38
Q

Chlorampheicol MOA and SOA

A

binds 50S subunit and inhibits protein synth at the peptidyl transferase reaction
Broad SOA against anaerobes
Not good for pseudomonas or chlamydia

39
Q

Chlorampheicol PK

A

Completely absorbed orally

Enters CSF

40
Q

Chlorampheicol AE

A

Hemolytic anemia
Aplastic anemia - fatal
Reversible anemia
Gray baby syndrome

41
Q

Chlorampheicol Warnings/Facts

A

Highly toxic - restricted to life-threatening infx with no other alternative

42
Q

Clindamycin Class and MOA

A 
Lincosamide
MOA: Binds irreversibly to 50S subunit 
Inhibits translocation steps of protein synthesis
Bacteriostatic
MOA same as macrolides
43
Q

Clindamycin SOA

A

Gm+ cocci and anaerobes (above diaphragm)
Good for osteomyelitis
Penetrating wounds of abdomen and gut

44
Q

Clindamycin PK

A

Well absorbed orally

Distributes well except CSF

45
Q

Clindamycin SE

A

C. diff leading to fatal pseudomembranous colitis

SE: diarrhea, rash, vomiting

46
Q

What medications do you think about when treating an anerobe?

A

Clindamycin or Metranidazole

For gut or female genital infx

47
Q

Linezolid (Zyvox) MOA

A

bind to 50S subunit to prevent formation of initiation complex for protein synthesis
Bacteriostatic for staph and enterococci
Bacteriocidal for strep

48
Q

Linezolid (Zyvox) SOA

A

Gm+ and anaerobes
MRSA, VRE, enterococcus faecium and faecalis, bad skin infx
Atypicals: Chlamydia, Mycoplasma, Legionella

49
Q

Linezolid (Zyvox) DOC for?

A

Vanco resistant enterococcus (VRE)

MDR TB

50
Q

Linezolid (Zyvox) PK

A

No dose adjustment needed for renal, hepatic, or age

100% oral absorption

51
Q

Linezolid (Zyvox) SE

A

GI, NVD, HA, thrombocytopenia, C. diff
BM suppression, neuropathy, lactic acidosis, optic neuritis
Weak MAOI action: boosts dopamine, serotonin etc.
Avoid ETOH, aged cheese, high tyramine food

52
Q

Lincomycin

A 
Lincosamide
Rarely used except in pts with bad infx and PCN allergy
SE: C. diff, BM suppression
Narrow SOA: Gm+ and mycoplasma
Similar to macrolides

ID Pharm (6 decks)

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