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Block G -- Infection > Dr. Karatzios -- Antimicrobial Antibiotics > Flashcards

Dr. Karatzios -- Antimicrobial Antibiotics Flashcards

Contains only information highlighted in yellow from his slides

1
Q

4 potential pathogens that affect the nose and sinus

A
  • S. pneumoniae
  • GAS
  • S. aureus
  • H. influenzae
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2
Q

1 potential pathogen that may affect the throat/pharynx

A

GAS

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3
Q

5 potential pathogens that may affect the lungs/bronchi

A
  • S. pneumoniae
  • H. influenzae
  • S. aureus
  • Klebsiella spp.
  • Other enterbacteriaceae
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4
Q

1 potential pathogen that may affect the middle ear

A

S. pneumoniae

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5
Q

3 potential pathogens that may affect the stomach/duodenum and intestines

A
  • Salmonella
  • Shigella
  • E. coli O157:H7
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6
Q

2 potential pathogens that may affect the urinary tract

A
  • Enterobacteriaceae
  • Enterococcus
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7
Q

5 potential pathogens that may affect the CNS

A
  • N. meningitidis
  • H. influenzae
  • S. pneumoniae
  • Listeria
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8
Q

4 potential pathogens that may affect the eye

A
  • Haemophilus
  • Moraxella
  • N. gonorrhoeae
  • S. pneumoniae
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9
Q

2 potential pathogens that may affect wounds

A
  • S. aureus
  • GAS
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10
Q

3 potential pathogens that may affect bone and joint

A
  • S. aureus
  • GAS
  • Kingella kingae
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11
Q

6 antibiotics that have such good bioavailability that po=IV

A
  1. Clindamycin
  2. Fluoroquinolones
  3. Septra
  4. Tetracyclines
  5. Metronidazole
  6. Lindezolid
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12
Q

2 rate limiting steps that prevent someone from taking antibiotics orally even if bioavailability is so good that po = IV

A
  • GI tolerance
  • GI absorption (i.e. if patient is nauseated)
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13
Q

Define time-dependent activity

A

Depends on the AMOUNT of time that is spent above the minimum inhibitory concentration of the organism for that specific antibiotic at that specific place/tissue/organ

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14
Q

Define concentration-dependent activity

A

Depends on the CONCENTRATION above the minimum inhibitory concentration of the organism for that specific antibiotic at that specific place/tissue/organ

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15
Q

Mechanism of action of beta-lactams

A

Inhibition of cell wall synthesis by binding to penicillin binding proteins

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16
Q

3 modes of resistance that bacteria have developed against beta-lactams

A
  • Inactivation of antibiotic (penicillinase or beta-lactamase; i.e. most MSSA)
  • Mutated penicillin-binding protein (i.e. MRSA)
  • Decrease in penetration of antibiotics
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17
Q

Activity dependence of beta lactams

A

Time-dependent

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18
Q

5 families of beta-lactam antibiotics

A
  1. Penicillins
  2. Clavulanic acid
  3. Carbapenems
  4. Nocardicins, monobactams
  5. Cephalosporins, cephamycins, cephabacins
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19
Q

Organisms typically covered by penicillins

A
  • Gram-positive
  • Gram-positive anaerobes
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20
Q

Reason for S. aureus resistance to penicillin

A

Penicillinase

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21
Q

Reason for gram negative enterobacteriaceae resistance to penicillin

A

Beta-lactamases

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22
Q

Example of a new, resistant pathogen to penicillin

A

Pseudomonas spp.

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23
Q

2 penicillins designed to counter s. aureus and a potential drawback of these

A
  1. Cloxacillin
  2. Methicillin

Problem: gain in S. aureus activity = loss of anaerobic activity

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24
Q

2 penicillins designed to have expanded gram negative coverage (i.e. for e. coli)

A
  1. Ampicillin IV
  2. Amoxicillin (Amoxil) po

Both = aminopenicillins

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25
Q

2 penicillins designed to counter pseudomonas aeruginosa

A
  1. Ticarcillin
  2. Piperacillin
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26
Q

Side effect of beta-lactamase inhibitors

A

Diarrhea

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27
Q

5 types of organisms covered by penicillins + beta-lactamase inhibitors

A

BROAD SPECTRUM:

  1. S. aureus
  2. Most gram + (i.e. enterococcus and listeria spp.)
  3. Most gram neg. respiratory pathogens (i.e. haemophilus and moraxella spp)
  4. Most gram neg. enteric bacteria
  5. Most anaerobes (gram + and -)
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28
Q

6 types of organisms covered by timentin + pip/tazo

A

BROAD SPECTRUM:

  1. S. aureus
  2. Most gram + (i.e. enterococcus and listeria spp.)
  3. Most gram neg. respiratory pathogens (i.e. haemophilus and moraxella spp)
  4. Most gram neg. enteric bacteria
  5. Most anaerobes (gram + and -)
  6. **AND pseudomonas spp.
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29
Q

General trend of activity of cephalosporins

A
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30
Q

Gram negative exceptions to the general trend of cephalosporin activity

A

*Pseudomonas *spp.

  • No activity with 1st and 2nd generation
  • 3rd generation = ONLY ceftazidime
  • 4th generation = yes

*Campylobacter *spp. = no activity with ANY generation

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31
Q

Gram positive exceptions to the general trend of cephalosporin activity

A

*Enterococcus spp**. and **Listeria *spp. = no activity whatsoever with ANY generation

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32
Q

Organisms covered by carbapenems

A

BROAD SPECTRUM (similar to beta-lactams/beta-lactamase inhibitor combinations)

  • Gram + (MSSA)
  • Gram -
  • Anaerobes

NOTE: Usually resistant to beta-lactamases

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33
Q

Recent emergence of what type of organism that is resistant to carbapenems?

A

Gram-netaive enteric rods

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34
Q

3 mild side effects of all beta-lactams

A
  • GI upset
  • Diarrhea (beta-lactamase inhibitors; cefixime/Suprax)
  • Drug-induced neutropenia
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35
Q

2 serious side effects of beta lactams

A
  • Seizures (up to 14g threshold)
  • Anaphylaxis (10% cross-reactivity between penicillins and carbapenems)
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36
Q

Beta lactam that lowers the seizure threshold more than others

A

Imipenem

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37
Q

5 beta-lactams that cross the BBB appreciably

A
  1. Penicillin IV (high dose)
  2. Ampicillin IV (high dose)
  3. 3rd gen. cephalosporins IV (high dose)
  4. Cefepime
  5. Carbapenems
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38
Q

6 Beta-lactams that have activity against MSSA

A
  1. Cloxacillin po/IV (and methicillin)
  2. Beta-lactam/beta-lactamase combinations (po/IV)
  3. 1st generation cephalosporins po/IV
  4. 2nd generation cephalosporins po/IV
  5. Cefepime
  6. Carbapenems

NOTE: 3rd generation IV NOT that good – just OK

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39
Q

5 beta-lactams with activity against *Pseudomonas *spp.

A
  1. Ticarcillin and Piperacillin (IV)
  2. Timentin and Pip/tazo (IV)
  3. Ceftazidime (IV)
  4. Cefepime (IV)
  5. Carbapenems (IV)
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40
Q

3 beta-lactams that have activity against anaerobes

A
  1. Penicillin (po/IV)
  2. All beta-lactam/beta-lactamase combinations (po/IV)
  3. Carbapenems (IV)
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41
Q

Mechanism of action of vancomycin

A

Inhibition of the cross-linking of peptidoglycan

42
Q

Antibacterial spectrum of vancomycin

A
  • Only gram-positive
  • Includes anaerobic gram-positive
  • Very good against C. difficile (oral)
43
Q

Penetration of vancomycin (3 points)

A
  • BBB penetration, mainly with inflammation
  • Need higher levels to penetrate BBB, bone and cartilage, heart tissue
  • Need higher levels when dealing with MRSA
44
Q

2 adverse reactions of vancomycin

A
  1. Nephrotoxicity
  2. Histamine release (red-man syndrome) when administered over short period (< or = 1 hour)
45
Q

2 reasons why nephrotoxicity would occur with vancomycin

A
  • Usually with accumulation (high trough levels)
  • When co-administered with other nephrotoxic drugs
46
Q

3 manifestations of red-man syndrome

A
  1. Flushing
  2. Hives
  3. Even hypotension
47
Q

2 types of gylcopeptide antibiotics

A

Vancomycin

Teicoplanin

48
Q

3 macrolide antibiotics

A
  • Erythromycin (IV/po)
    • i.e. Erythromycin estolate (po)
  • Clarithromycin (po)
    • i.e. Biaxin
  • Azithromycin (IV/po)
    • i.e. Zithromax
49
Q

Ketolide antibiotic

A

Telithromycin (po)

Example = Ketek

50
Q

Antibacterial spectrum of macrolides and ketolides (4 types)

A
  • Gram-positives
  • Gram-negatives
  • Atypical bacteria
  • Non-tuberculous mycobacteria
51
Q

2 gram-positive bacteria that are affected by macrolides/ketolides if S

A
  • S. pneumoniae
  • GAS
52
Q

2 examples of gram-negatives affected by macrolides/ketolides

A
  • *Campylobacter *spp.
  • Bordetella pertussis
53
Q

3 examples of atypical bacteria affected by macrolides/ketolides

A
  • *Mycoplasma *spp.
  • *Chlamydia *spp.
  • *Clamydophila *spp.
54
Q

2 macrolides that affect non-tuberculous mycobacteria

A
  • Clarithromycin
  • Azithromycin
55
Q

5 aminoglycosides

A
  1. Gentamicin
  2. Tobramycin
  3. Amikacin
  4. Streptomycin
  5. Paromomycin
56
Q

General antibacterial spectrum of aminoglycosides

A

Gram-negative (including *P**seudomonas *spp.)

57
Q

Exceptions to the gram-negative rule of aminoglycoside coverage (2)

A
  • *Salmonella *spp.
  • *Neisseria *spp.
58
Q

2 bacteria that only some aminoglycosides have activity against

A

TB and non-TB mycobacteria

59
Q

Aminoglycoside that has anti-parasitic activity and the parasite against which it acts

A

Paromomycin for giardia lamblia

60
Q

3 adverse reactions of aminoglycosides

A
  • Renal toxicity
  • Vestibular and cochlear toxicity
  • Muscular blockade
61
Q

2 reasons that renal toxicity may occur with aminoglycosides and whether it is reversible

A
  1. High trough levels
  2. Increased if co-administered with other nephrotoxic drugs

Reversible = YES

62
Q

Reason for vetsibular and cochlear toxicity with aminoglycosides and whether it is reversible

A

Usually due to prolonged use

IRREVERSIBLE hearing loss

63
Q

First problem sign of vestibular and cochlear toxicity with the use of aminoglycosides

64
Q

For which patients should aminoglycosides be avoided

A

People with neuromuscular diseases (due to muscular blockade)

65
Q

3 fluoroquinolones

A
  • Ciprofloxacin po/IV (Cipro)
  • Levofloxacin po/IV (Levaquin)
  • Moxifloxacin po (Avelox)
66
Q

The respiratory quinolone

A

Levofloxacin po/IV (Levaquin)

67
Q

Antibacterial spectrum of fluroquinolone –> trends against:

  • S. pneumoniae
  • MSSA
  • Enteric gram negative rods
  • Pseudomonas spp.
  • Atypicals
68
Q

2 bacteria for which fluoroquinolone coverage is only achieved by 4th generation

A
  • Enterococcus faecalis
  • Anaerobes
69
Q

Oral vs. IV availability of fluoroquinolones

70
Q

3 sulfonamides

A
  1. Trimethoprim-sulfamethoxazole (Septra)
  2. Sulfadiazine
  3. Dapsone
71
Q

Antibacterial spectum of Septra (3 main points)

A

BROAD SPECTRUM – all bacteria requiring endogenous folic acid synthesis

  • Gram + and gram -
    • Includes:
      • Enterobacteriaceae
      • Shigella
      • S. maltophilia
      • B. cepacia
      • Chlamydia
      • Nocardia

​Anti-parasitic activity: Toxoplasma

Anti-fiungal activity: Pneumocystis jeroveci

72
Q

2 organisms against which septra has no activity

A
  • GAS
  • *Enterococcus *spp.
73
Q

Oral vs. IV availability of sulfonamides

74
Q

3 types of organisms covered by tetracyclines

A
  1. Gram-negative enteric rods
  2. Anaerobes
  3. Atypical bacteria
75
Q

4 types of organisms covered by tigecycline

A
  1. Gram-negative enteric rods
    • Even those resistant to tetracyclines
    • Multiresistant enterbacteriaceae
  2. Gram-positive
  3. Anaerobes
  4. Atypical bacteria
76
Q

3 types of gram-positive bacteria that are susceptible to tigecycline even though they are resistant to other antibacterials

A
  • MRSA
  • VRE
  • Penicillin-resistant S. pneumoniae
77
Q

Oral vs. IV availability of the “cyclines”

78
Q

Mechanism of actio nof clindamycin

A

Inhibition of protein synthesis

79
Q

Resistance of clindamycin (2)

A
  • Modification of target site
  • Efflux pump

NOTE: similar to macrolides (most gram-negatives have intrinsic resistance to macrolides)

80
Q

Activity dependence of clindamycin

A

Bacteriostatic time-dependent activity

81
Q

Antibacterial spectrum of clindamycin (4 points)

A
  • Good gram-postiive coverage (incl. *S. pneumoniae *and S. aureus)
    • ONLY if erythromycin S
  • Good anaerobic activity
  • NO gram-negative coverage
  • **NO ***Entercoccus *spp. activity
82
Q

Oral availability equivalence of clindamycin

A

Oral = IV/IM availability

83
Q

2 adverse effects of clindamycin

A
  • May cause moderate diarrhea
  • Associated with *C. difficile *colitis
84
Q

Coverage of metronidazole (2)

A
  • Anaerobes (gram + and gram -)
    • C. difficile
  • Antiparasitic activity
85
Q

2 parasites against which metronidazole works

A
  • Giardia lamblia
  • Entamoaba histolytica
86
Q

Oral availability equivalence of metronidazole

87
Q

Why shouldn’t you use rifamycins alone

A

On their own, induce RAPID resistance

  • Always use with other antibiotics as buffer
  • Can be used alone as prophylaxis
88
Q

Situation wherein rifamycin can be used alone as prophylaxis

A

Post-exposure prophylaxis against development of meningitis from *N. meningitides *and H. influenzae

89
Q

2 treatment uses for rifamycins

A
  1. TB
  2. Non-TB mycobacteria
90
Q

Major drug interactions of rifamycins

A

Both are metabolized in the liver and induce CYP-450 enzymes

91
Q

2 rifamycins

A
  • Rifampin
  • Rifabutin
92
Q

3 general adverse reactions of rifamycins

A
  • Nausea
  • Increase in liver enzymes
  • Skin rashes
93
Q

Specific adverse reaction of rifampin

A

Oreange-red coloration of body fluids (urine,tears)

–> May permanent contact lenses

94
Q

2 specific adverse reactions of rifabutin

A
  • Bronze discoloration of skin
  • Violet-red coloration of urine
95
Q

Only use for nitrofurantoin and why

A

UTI treatment and prophylaxis

(Therapeutic concentrations achieved ONLY in urine)

96
Q

3 antibiotics specifically produced for multiresistant gram-positive bacteria (MRSA AND/OR VRE)

A
  1. Oxazolidinones
    • Linezolid
  2. Streptogramins
    • Quinipristin/Dalfopristin
  3. Daptomycin
97
Q

Oral availability equivalence of linezolid

98
Q

2 averse reactions of linezolid

A
  • Reversible thrombocytopenia
  • Serotonin syndrome (inhibitor of monamine oxydase)
99
Q

When is there an increased risk of thrombocytopenia when using linezolid

A

Prolonged treatment >2 weeks

100
Q

2 things to avoid when administering linezolid to a patient

A
  • Avoid SSRI
  • Avoid or limite tyramine-containing foods (i.e. cheeses, smoked and processed meats)

Block G -- Infection (23 decks)

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