antibiotics Flashcards

1
Q

what is essential for antibacterial activity? (structure of antibiotic?)

A

ring

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2
Q

what enzyme disrupts the beta-lactam ring? why is this bad?

A

betalactamase

it is a major mechanism of action in acquiring resistance

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3
Q

what do beta-lactams do? long or short half life? where are they eliminated?

A

inhibit cell wall synthesis ***
bactericidal
short half life
renal

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4
Q

what does cross-sensitivities mean in re: beta-lactams?

A

penicillin is a beta-lactam antibiotic and therefore cross react with other beta-lactam antibiotics ie.) penicillins (ill ins), cephalosporins (1,2,3, and 4th generators so like ancef any ‘ref’, and carbapenems (ertapenem, imipenem, and dilantin) and monobactam ??

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5
Q

what are the different types of beta lactams?

A

penicillins, cephalosporins, carbapenems, monobactams

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6
Q

if you can’t take ancef or other beta-lactams then what do you give pre-op?

A

gentamicin or vancomycin

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7
Q

MOA of beta-lactams?

A

inhibits synthesis of bacterial cell walll

  • binding with proteins,
  • produces defective cell wall, which destroys microorganism
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8
Q

penicillins first admin? why not injections?

A

**had to be given parenterally.
injections were painful (given w lidocaine)

destroyed by gastric acid

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9
Q

extensive use of penicillins produced what?

A

drug resistant strains of staphylococci

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10
Q

what is the prototype of penicillins? **

A

** penicillin G

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11
Q

where does penicillin achieve therapeutic concentrations?

A

in most body fluids.

produces high drug concentrations n urine

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12
Q

where is penicillin excreted

A

in kidneys.

produces high drug concentrations in urine (except naficillin)

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13
Q

what risk is there for penicillins?

A

risk of hypersensitivity ***

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14
Q

contraindications for penicillins?

A

hypersensitivity or allergic reaction. potential for **cross- sensitivity with cephalosporins and carbapenems

in life threatening allergic reactions to PCN, cephalosporin and carbapenem use is to be avoided

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15
Q

indications for use of penicillins?

A

bacterial infections caused by susceptible organisms
more effective in gram pos than gram neg infections
-skin/soft tissue, respiratory, GI and GU infections
-incidents of resistance continue to increase

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16
Q

Is the following statement True or False?

The mechanism of action for beta-lactam antibiotics is to prevent the duplication of bacterial cells.

A

false Rationale: The mechanism of action for beta-lactam antibiotics is to produce a defective cell wall, which results in the destruction of the microorganism.

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17
Q

can you keep taking penicillin and does it continue to always work?

A

no, it is effective for a limited number of uses?

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18
Q

is penicillin G effective orally, IV and injectable form? why or why not

A

just injectable form (at island health)

it is ***not effective orally (inactivated by gastric acid)
IV admin may cause cardiopulmonary arrest an death

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19
Q

what is penicillin V? how can you administer it?

A

subgroup of penicillin. derived from penicillin G. not destroyed by gastric acid

oral liquid and oral solid ofrm

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20
Q

what kind of penicillin is ampicillin?

A

broad spectrum penicillin

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21
Q

what kind of organisms are broad spectrum penicillins good for?

A

gram neg mores than gram positive

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22
Q

how to admin broad spectrum antibiotics?

A

available orally for UTIs, prostatitis
intermittent IV dosing
most can be given IM

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23
Q

first abx developed?

A

penicillin

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24
Q

what is a beta-lactamase inhibitor

A

the beta-lacamse is the enzyme that destroys the betalactam (which inhibits synethesis of bacterial cell wall) so this inhibits that enzyme

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25
Q

what do beta-lacramase inhibitors do?

A

very little antibacterial activity

bind with inactive betalactamase and protects penicillin from destruction and extends its spectrum of efficacy

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26
Q

what are cephalosporins? what are they derived from?

A

widely used group of meds (broad-spectrum atb) that are derived from fungus

27
Q

what organism do cephalosporins work against

A

moreso gram neg than positivel

28
Q

where do cephalosporins distribute to? max concentration?

A

most body fluid and tissues

max concentration in liver and kidneys

29
Q

clinical indications for use of cephalosporins?

A

surgical prophylaxis (cefazolin)

treatment of infections

  • resp tract, urinar tract
  • skin, soft tissues
  • bones, joints
  • brain, spinal cord; septicemia
30
Q

what drug is given with cephalosporins to prolong drug of a action?

A

probenecid. also delays renal clearance so want to watch I&O

31
Q

what drug can increase effect of warfarin?

A

metronidazole (flagyl)

32
Q

contraindications for cephalosporins?

A

previous anaphylactic reaction to PCN, cross sensitivity low in those with delayed reactions to PCN
-skin rash
or an allergy

33
Q

what are carbapenems?

A

broad-spectrum, bactericidal beta-lactam antibicrobials

usually given when other abx are not working

34
Q

what do carbapenems do? MOA

A

inhibit synthesis of bacterial cell walls by binding penicillin-binding proteins

35
Q

monobactam (aztreonam) is active against what kind of bacteria?

A

gram neg bacteria

active against many strains that are abx resistant

36
Q

T or F monobactam causes kidney damage and hearing lose

A

F it does not. as can aminoglycosides

37
Q

indications for use of monobactam?

A

urinary tract, skin/skin structures, lower resp tract, intra-abdominal and gynecologic infections, septicemia

38
Q

aztreonam is pharmacare high or low cost drug for the cyclic treatment of what?

A

Aztreonam is a PharmaCare high-cost drug (requires special authority) for the cyclic treatment of chronic Pseudomonas aeruginosa infections in patients with moderate to severe cystic fibrosis only

39
Q

drug selection of antimicrobial therapy depends on what?

A

Depends on organism causing infection
Severity of infection
Other factors

40
Q

gram negative- infections that tend to occur where? what are some examples of bacteria?

A

below the diaphragm

e-coli, helicobacter, acinetobacter

41
Q

gram positive infections tend to occur where? what are some examples of bacteria?

A

above the diaphragm

staphylococcus aureus and MRSA
streptococcus and pneumococci

42
Q

whats the difference between gram positive and negative?

A

different class of bacteria that take up the crystal violet stain used int he gram staining method of bacterial differentiation

43
Q

what does bactericidal mean? (abx classification)

A

**kills organisms. preferred in serious infections, especially in people with impaired immune function

44
Q

what does bacteriostatic mean?

A

**ihibits growth of organisms
treatment depends on the ability of the hosts immune system to eliminate the inhibited bacteria and an adequate duration of drug therapy ***

45
Q

are beta-lactams bacteriostatic or bactericidal?

A

bactericidal

46
Q

where do you find normal microbial flora?

A

sterile areas like body fluids, vacuities, the lower respiratory tract, much of the GI, GU and musculoskeletal system

47
Q

what are colonized areas?

A

**present but no symptoms so they have bacteria but without symptoms and when you do have symptoms then you’re infected

48
Q

what is the point of normal flora?

A

protects the human host by occupying space and consuming nutrients. this interferes with the ability of potential pathogens to establish residence and proliferate

49
Q

what does normal bowel flora do?

A

synthesizes vit k and vit b complex

50
Q

T or F

much of the normal flora can cause disease under certain conditions

A

T.

e.g. elderly, debilitated, or immunosppressed

51
Q

infections disease involves what ___ **

A

the presence of a pathogen plus clinical signs and symptoms indicative of an infection

52
Q

what are opportunistic pathogens?

A

usually normal flora that become pathogens in hosts where defence mechanisms are impaired **

53
Q

who are more likely to receive opportunistic infections?

A

are likely to occur in people with severe burns, cancer, human immunodefi ciency virus (HIV) infection, indwelling intravenous (IV) or urinary catheters, and antibiotic or corticosteroid drug therapy. Oppor-tunistic bacterial infections, often caused by drug-resistant micro-organisms, are usually serious and may be life threaten-ing. Fungi of the Candida genus, especially C. albicans, may cause life-threatening bloodstream or deep-tissue infections, such as abdominal abscesses.

54
Q

what are nosocomial infections?

A

may be more severe and difficult to manage because they often result from drug-resistant micro-organisms in people whose resitstance to disease is impaired

55
Q

anti-infective and antimicrobial include what?

A

antibacterial, antiviral, and antifungal

56
Q

do you generally use broad-spectrum drugs or avoid?

A

avoid **

57
Q

what do you follow for recommendations for abx/

A

centres for disease control and prevention

58
Q

do not repeat same abx within ___ days

A

**90

59
Q

what are some other interventions other than abx?

A

fluids and erst, vaccinations

60
Q

if indicated collet specimens before when?

A

beginning therapy **

61
Q

what is MIC and MBC?

A

laboratory reports organism susceptibility, resistance and minimum inhibitory concentration (MIC) and/or minimum bactericidal concentration (MBC)

62
Q

route of admin for abx?

A

most PO or IV

1X IM dose

63
Q

duration of therapy for abx? most infections last how long?

A

varies from single dose to years. Most acute infections 7-10 days

64
Q

perioperative dose- when do u give?

A

single dose given within2 hours of first incision ***