Bacterial Protein Synthesis Inhibitors Flashcards

0
Q

Tobramycin

A

Aminoglycoside

MOA: inhibit translation by binding to 16S rRNA of 30s ribosomal subunit causing misreading and leading to cell death

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1
Q

Gentamicin

A

Aminoglycoside

MOA: inhibit translation by binding to 16S rRNA of 30s ribosomal subunit causing misreading and leading to cell death

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2
Q

Amikacin

A

Aminoglycoside

MOA: inhibit translation by binding to 16S rRNA of 30s ribosomal subunit causing misreading and leading to cell death

Best against pseudomonas

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3
Q

General aminoglycosides characteristics, spectrum of use , side effects

A

Bactericidal
Concentration dependent
Very low bioavailability
Renal eliminated
Sub- optimal penetration of sputum/lung, bone, CNS, abscesses
Excellent against enterobacteraciae, acinetobacter, pseudomonas, other gnr
+ cell wall active agent has good activity vs many GPC

SE: Nephrotoxicity, ototoxity

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4
Q

Amino glycosides main uses and resistance is from what

A
Uses: 
Gram-  nosocomial Infections 
Mycobacterial infections ( Amikacin, streptomycin) 
Pseudomonal infections 
Gram + synergy in endocarditis 

Resistance
Enzymatic inactivation ( enterobacteraciae)
Altered membrane permeability ( pseudomonas)
Target site mutation

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5
Q

Clindamycin

A

Lincosamides

Moa: inhibits translation by binding the 50s subunit of bacterial ribosomes. -> inhibits peptidyl transferase
Basteriostatic
90% bioavailable

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6
Q

Lincosamides general characteristics

A

Anaerobes, but C. difficile
Staphylococci ( including some MRSA) streptococci, anaerobes
- not good for MRSA pneumonia or atypicals

Se:pseudo membranous colitis

Uses: aspiration pneumonia, SSTIs, anaerobic infections, (topical )acne

Resistance is due to altered target site
- in gram positives , often cross- resistant with macro lodes, streptogramins.

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7
Q

Erythromycin

A

Macrolide

MOA: inhibit translation by binding 23s rRNA of 50s subunit of ribosome

Bacteriostatic

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8
Q

Clarithromycin

A

Macrolide

MOA: inhibit translation by binding 23s rRNA of 50s subunit of ribosome

Bacteriostatic

H. Pylori
More convenient dosing than erythromycin

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9
Q

Azithromycin

A

Macrolide

MOA: inhibit translation by binding 23s rRNA of 50s subunit of ribosome

Bacteriostatic
More convenient dosing than erythromycin

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10
Q

Macrolides general characteristics

A

Achieve high intracellualr concentrations
Highly bioavailable
Excellent lung penetration , poor CNS
Hepatic metabolism or biliary excretion
Uses: streptocussous spp, atypical pathogens, h. Influenza, m. Catarrhalis

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11
Q

Macrolides adverse effects

A

GI disturbances , rash

Drug interactions
Erythro and clarithro inhibit CYP 1A2, 3A3/4

Azithro lower interaction potential

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12
Q

Main use of Macrolides and resistance to Macrolides

A
Uses 
Cap 
URTIs
MAC 
PUD clarithro
 Promotility ( erythromycin ) 

Resistance
Efflux pump, altered target site

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13
Q

Telithromycin

A
Ketolide
Microlide analogue with increased s. Pneumoniae activity 
Po only 
Addition ae : hepatotoxicity 
Main use - CAP
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14
Q

Minocycline

A

Tetracycline

MOA : inhibit translation by binding reversibly to 16s rRNA of 30s ribosomal subunit , blocking tRNA from binding ribosome-mRNA complex

Bacteriostatic

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15
Q

Tetracycline

A

Tetracycline

MOA : inhibit translation by binding reversibly to 16s rRNA of 30s ribosomal subunit , blocking tRNA from binding ribosome-mRNA complex

Bacteriostatic

16
Q

Doxycycline

A

Tetracycline

MOA : inhibit translation by binding reversibly to 16s rRNA of 30s ribosomal subunit , blocking tRNA from binding ribosome-mRNA complex

Bacteriostatic

17
Q

Doxycycline

A

Tetracycline

MOA : inhibit translation by binding reversibly to 16s rRNA of 30s ribosomal subunit , blocking tRNA from binding ribosome-mRNA complex

Bacteriostatic

18
Q

Tetracyclines characteristics , adverse effects and drug interactions

A
Concentration independent 
Highly bioavailable 
Poor CNS penetration 
Spectrum 
- atypicals 
- some gnr and GPC, limited by resistance 
- bacillus anthracis, b. Burgdorferi , y. Pestis, t. Pallidium, h. Pylori. 
- some MRSA 

Adverse effects

  • tooth discoloration
  • GI upset- n/v, borborygmous
  • photosensitivity
19
Q

Tetracyclines - main uses and resistance

A

Acne, CAP (doxycycline) , tick-borne diseases, PUD, STDs
- demeclocycline’s only use is SIADH

Resistance due to efflux pump

20
Q

Tigecycline

A

Glycycyline

Modified tetracycline that has an expanded spectrum 
Very large vd
Hepatic elimination 
Covers many gnr and GPC
- includes vre and MRSA 
Good anaerobic - not c. Difficile 
Not pseudomonas or. Proteus 

Ae - significant n/v

Use: SSTIs, intra-abdominal infections
Not good enough for HAP

21
Q

Chloramphenicol

A

MOA: binds to 23s rRNA of 50s subunit inhibiting protein synthesis by blocking peptidyl transferase

Bacteriostatic

Highly bioavailable
PO= IV dosing

22
Q

Chloramphenicol characteristics

A

Good CNS penetration
Hepatic all metabolized through conjugation
Useful spectrum
- streptococci, staphylococci ( Methicillin sensitive only), enterococci including VRE
-anaerobes
- some GNR

23
Q

Chloramphenicol adverse effects and drug interactions

A

Adverse effects
- gray baby syndrome - d/t neonatal impairment of. Conjugation
Vomiting , flaccidity, gray color,response distress, met acidosis

  • bone marrow suppression. - reversible - dose related , irreversible
    idiopathic

Drug interactions:
Increased levels of phenytoin, phenobarbital, warfarin

Used: not in USA, vre infections

Resistance : enzymatic inactivation

24
Q

Quinupristin / dalfopristin

A

Streptogramins

MOA bind to different parts of 23s rRNA of 59s subunit, halting protein synthesis

IV only

25
Q

Strepogramins characteristics

A

Bactericidal in combo vs Mssa, MRSA streptococci
Bacteriostatic vs enterococcus faecium

Hepatically metabolized
Some CNS penetration

26
Q

Adverse effects and drug interactions of streptogramins

A

Phlebitis
Severe myalgias
Hepatotoxicity
Line crystallizations when mixed with saline

Drug interactions
Cyp450 3a4 inhibitors - causes increased levels of cyclosporine, nefidipine, midazolam, tacrolimus, other agents

27
Q

Main uses and resistance to streptogramins

A

Vanco resistant enterococcus faecium infections

  • MRSA infections in patients who cannot take other agents

Resistance due to altered target sites

28
Q

Linezolid

A

Oxazolidinones

MOA: binds to 23s rRNA of 50s subunit preventing protein synthesis by blocking formation of 70s initiation complex

Binding site is distinct from their protein synthesis inhibitors

29
Q

Oxazolidinones characteristics

A

Bacteria statics vs enterococci and staphylococci
Bactericidal vs streptococci

PO =IV dosing
Dual hepatic metabolism not via cyp450 and renal elimination

Weak, reversible inhibitor of monoamine oxidase

30
Q

Oxazolidinones monoamine oxidase inhibition

A
  • Avoid Tyramine-containing foods
  • Be cautious with SSRIs, TCAs avoid other MAOIs with Linezolid therapy
  • pressor effects may increase
31
Q

Oxazolidinones spectrum and ae

A

Spectrum :
Gram-positive aerobes - staphylococci (including MRSA) , streptococci (including pcn- resistant strains) enterococci (including vre)

Ae:
Potential for increased BP with Tyramine containing foods
Myelosuppression, thrombocytopenia

Uses: MRSA or vre infections
Resistance : altered target site