Antimicrobials Flashcards Preview

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Flashcards in Antimicrobials Deck (90):
1

What does a gram (+) stain look like

purple, single lipid bilayer with thick pept. cell wall

2

What does a gram (-) stain look like

red, double lipid bilayer with thin pept. cell wall

3

Cocci

spherical

4

Bacilli

rod

5

Aerobic

oxygen loving

6

Anaerobic

oxygen hating

7

Blood brain barrier- factors influencing drug penetration

• Protective mechanism = stops entry into brain
• Single layer tile-like endothelial cells fused by tight junctions
• Resistant to hydrophilic drugs
• Gain entry = high lipophilicity, increased inflammation of BBB, low molecular weight, decreased binding (free serum overall)

8

Bacteriostatic

stops growth of bacteria and limits spread of infection during immune system attack

9

Bacteriocidal

kills bacteria

10

Bacteriostatic list

CLM, TTTT, SSSS
Clindamycin*
Linezoid
Macrolides*

Tetracycline
Tigecycline
Trimethoprim

Sulfonamides
Spectinomycin
Synercid



11

Bacteriocidal list

A B C D
FVM

Aminoglycosides
Beta-lactam
Cephalosporines
Daptomycin
Fluroquinolies
Vancomycin
Metronidazole

12

Gram (+) pearls

• Staphylococcus
• Streptococus
• Enterococcus

13

Gram (-) pearls

Haemophilius influenza (easy to treat)
FENCE bugs (easy/hard)
SPACE bugs (hard to treat)

14

FENCE bugs

Proteus mirabilis
E. Coli
Klebsiella PNA

15

SPACE bugs

• Serratia
• Pseudomonas
• Acinetobacter
• Citerobacter
• Enterobacter

16

Organism susceptibility

a guide for choosing antimicrobial therapy once a pathogen is cultured. Includes MIC, MBC, antibiogram

17

Concentration dependent killing

significant increase in rate of bacterial killing as the concentration of abx increases (cmax) à more rapid killing

18

Two meds that use concentration dependent killing are?

o Aminoglycosides
o Fluoroquinolones

19

Time dependent killing

increasing the concentration of antibiotic does not increase the rate of kill. It is based on clinical efficacy via percentage of time that blood concentration of the drug remain above the MIC (fT >MIC)

20

Post antibiotic effect

persistent suppression of microbial growth that occurs after levels of abx have fallen below the MIC

21

Narrow Spectrum

single/limited group of microorganisms

22

Extended Spectrum

gram (+) organisms and significant number of gram (-) organisms

23

Broad Spectrum

wide variety of microbial species (precipitates superinfections)

24

Combination therapy

combo of abx/synergism with a disadvantage of interfering with mechanisms of action, overuse, and cost

25

Synergy

combination drugs, better coverage together than alone

26

Resistance

genetic alterations, altered expression of protein

27

Genetic alterations

DNA/protein mutations à xfer drug resistence

28

Altered expression of proteins

modification of target sites, decreased accumulation (efflux pumps), and enzymatic inactivation (B-lactamases, acetyltransferases, esterases)

29

Superinfections

broad spectrum/combo of agents can lead to alterations of the normal microbial flora

30

the two big super infections are

C Diff
Yeast

31

What drug uses enzymatic inactivation as their MoR?

beta lactams

32

What drug uses modification of target site for their MoR?

Vancomycin

33

What drug uses:
enzymatic inactivation
Efflux pump
and ribsomal protective proteins as its MoR?

tetracycline

34

What drug uses:
alteration in amino glycoside uptake
modifying enzymes
alterations in ribosomal binding site for its MoR

aminoglycosides

35

What drug uses:
decreased accumulation/efflux pump
modification of target site (mef/erm) for its MoR ?

macrolides

36

What drug uses:
altered target sites
efflux pump for its MoR?

clindamycin

37

What drug uses:
alterations in ribosomal binding sites
enzymatic inactivation and
efflux pump for its MoR?

synercid

38

What drug uses alterations in ribosomal binding sites for its MoR?

linezoid

39

What drug uses alterations in target sites and
DNA
active cell wall permeability and
efflux pump for its MoR

fluoroquinolones

40

What drug uses impaired oxygen scavenging and alter ferrodoxin levels for its MoR?

metronidazole

41

What drug uses increased PABA production and point mutations as its MoR?

TMP-SMX

42

4 sites of action of antimicrobials

• Inhibitors of cell wall synthesis
• Inhibitor of protein synthesis
• Inhibitors of nucleic acid function or synthesis
• Inhibitors of metabolism

43

which class are inhibitors of cell wall synthesis

beta lactams (PCMC)
vancomycin

44

which classes are inhibitors of protein synthesis

tetracyclines
aminoglycosides
macrolides

45

which classes are inhibitors of nucleic acid formation or synthesis

Fluoroquinolones

46

which class is inhibitors of metabolism

TMP-SMX

47

Patient factors influencing selection of agents

Immune system
Renal dysfunction and Hepatic dysfunction – (may need dose decrease)
Poor perfusion (may need dose increase)
Age
Pregnancy
Lactation

48

Beta Lactams

Beta Lactamase Enzymes
Ethanol intolerance
Cephalosporin MTT side chain, hypoprothrombinemia (low vit K)
Neuro/Hem/GI
Interstitial Nephritis
Hypersensitivity (rash, anaphylaxis, death), Antibody production against penicillins

49

Cephalosporins can't cover what bug?

Enterococcus

50

Cephalosporin generation 1

gram (+) aerobes, limited with few gram (-) aerobes

51

Cephalosporin generation 2

- gram (+) aerobes, more active with gram (-) aerobes, 3 work on anaerobes (cefoxitin, cefotetan, cefmetazole)

52

Cephalosporin generation 3

less active against gram (+) greater against gram (-) aerobes

53

Cephalosporin generation 4

am (+) aerobes (ceftriaxone), gram (-) aerobes including pseudomonas aeruginosa and beta lactamase producing enterobacter sp.

54

Cephalosporin generation 5

best gram (+) coverage, CAP (MRSA), infections of skin/subcut tissue

55

which cephalosporins work on anaerobes?

cefoxitin
cefotetan
cefmetazole

56

T/F vancomycin treats gram (+) only

true

57

Vancomycin AEs/Contras

• Red-Man Syndromes (rate of infusion)
• Nephrotoxicity
• Ototoxicity
• Neutropenia/Thrombocytopenia
• Thombophlebitis

58

Tetracyclines AEs/Contras

•Effects on calcified tissue/bone and teeth deposition in pregnant women/children under 8
GI- N/V/D, pseduomembranous colitis
• Hypersensitivity- rash, pruritis, anaphylaxis, angioedema, urticaria
• Photosensitivity
• Hepatotoxicity


59

Aminoglycosides AEs/Contras

• Nephrotoxicity
o Nonoliguric azotemia (proximal tubule damage)
o Risk for elderly, underlying renal dysfuction with long therapy
• Ototoxicity
o 8th CN damage with irreversible vestibular/auditory toxicity
o Vestibular- dizziness, vertigo, ataxia (S,G,T)
o Auditory- tinnitus, decreased hearing (A,G)

60

Macrolides AEs/Contras

• QTc prolongation
• GI
o N/V/D, dyspepsia
o Erythro most common
• Cholestatic hepatitis
• Thrombophlebitis
• Ototoxicity
• Allergy

61

Clindaymycin AEs/Contras

• most associated w/ Cdiff
• GI symptoms
• Allergy
• Hepatotoxicity

62

which medication causes c diff the most

clindamycin

63

linezolid- Zyvox

o ADE= thrombocytopenia with tx >2wks, headaches, thrombocytopenia, reversible optic/peripheral neuropathy
o caution w/ SSRIs- serotonin syndrome, MOI

64

• Tigecycline (Tygacil)-

o D/N/V
o Acute pancreatitis
o Tooth discoloration

65

Fluoroquinolones

• covers atypical pathogens
• not recommended in pediatrics d/t tendon rupture,
• difference between newer and older agents and gram positive coverage,
• CNS issues
• Hepatotoxicity
• QTc prolongation…watch with other prolonging agents
• GI issues
• Must take 2 hours before or 4hrs after chelation with calcium, iron, aluminum, Mg meds

66

T/F Fluroroquinolones have post antibiotic effect

True

67

o TMP-SMX-

• GI issues
• Hematologic- leucopenia, thrombocytopenia, eosinophilia (should stop therapy)
• Dermatologic- sulfa allergy
o Steven Johnson Syndrome
o Photosensitivity
o Rash
• CNS- aseptic meningitis, sz, headaches
• Crystalluria

68

Metronidazole

• GI issues
• CNS (caution with preexisting CNS disorders)
• Disulfiram reaction with ETOH

69

Synercid

• venous irritation
• GI symptoms
• Rash
• Myalgias
• Hyperbilirubinemia
• Interaction warning= CYP3A4 inhibitor (Ca2+ blockers, cyclosporine, warfarin, HIV meds, statins, diazepam)

70

o Endemic Mycoses:

• Histoplasmosis
• Coccidiodomycosis
• Blastomycosis

71

o Opportunistic Mycoses:

• Cryptococcosis
• Candidiasis
• Aspergillosis
• Zygomycosis

72

3 types of polyenes

Ampho B
Lipid Ampho B
Nystatin

73

Ampho B

• Fungicidal/Fungistatic
• Does NOT penetrate CSF
• AEs-
• Infusion related (fever, chills)-premed
• Nephrotoxicity-give fluids before and after
• Elevated liver enzymes
• Hypokalemia
• Hypomag

74

o Lipid-based Ampho B

• Advantages- higher tissue conc, decreased infusion related reactions, marked decreased in nephrotoxicity, increased daily dose
• Good for people with renal insufficiency

75

o Nystatin

• Topical only
• Candida suppression

76

• Pyrimidines (Flucytosine)


• Combined with Ampho B
• Penetrates CSF
• AEs-
• Neutropenia
• Thrombocytopenia
• Bone marrow depression
• Hepatic dysfuction
• GI symptoms

77

what are the 4 azoles

Itraconazole
Fluconazole
Voriconazole
Posaconazole

78

Azoles

• AEs-
• GI-N/V abd pain, elevated LFTs
• Prolonged QTc
• Visual disturbances (voriconazole)
• Rash
• Nephrotoxicity

79

what are the 3 echincandins

Caspofungin
Micafungin
Anidulafungin

80

echincandins

• AEs- overall tolerated well
• N/V
• Flushing
• Elevated LFTs
• Infusion reaction
• Phlebitis
• Hypokalemia

81

• Griseofluvin

o Used for dermatophytosis
o AEs
• Serum sickness
• Hepatitis
o Drug Interactions
• Warfarin
• Phenobarb

82

• Terbinafine

o AEs
• GI upset
• Headache

83

• Topical Agents

o Miconazole
o Clotrimazole
• OTC
• Used for vulvovaginal candida or dematophytic infections

84

T/F • Viruses obligate intracellular parasites- invade host cells

True

85

• Acyclovir

o Treats HSV and VZV
o renal toxicity w/ IV
o neuro toxicities
o high doses of valtrex can cause HUS, thrombocytopenia, seizures, hallucinations, confusion

86

o Amantadine and Rimantadine-

• use for Influenza A only, high levels of resistance

87

o Oseltamivir and Zanamivir-

• Activity against Influenza A and B
• Should be administered w/i 30 hours of symptom onset – and not after 48hrs

88

what bacteria are not covered by carbapenems?

MRSA
VRE
Cdiff

89

Monobactams only work against?

gram (-) aerobes

90

Vanc only works against?

gram (+) aerobes