Part 2- Antimicrobial, antiseptic etc Flashcards

1
Q

what ABX do we use to treat syphilis

A

PCN-highly effective

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2
Q

Higher doses of this drug is needed to treat gonococci due to resistance

A

PCN

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3
Q

PCN is the drug choice for these 5 infections

A

pneumococcal
streptococcal
meningococcal
Treating all forms of actinomycosis and clostridial infections causing gas gangrene

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4
Q

prophylactic administration of PCN is highly effective against ___infection

A

streptococcal infections, accounting for its value in pts with rheumatic fever

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5
Q

Clinical indications for PCN

A

Transient bacteremia occurs in the majority of patients undergoing dental extractions, emphasizing prophylactic need of PCN for those patient with cardiac issues and tissue implants.

Transient bacteremia can accompany procedures such as T&A, GU, GI, and vaginal deliveries

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6
Q

Penicillin G IV 10 million U contains 16 mEq of potassium - what is the concern with this potassium administration

A

patients with renal dysfunction

may result in neurotoxicity and hyperkalemia

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7
Q

IF PCN G is needed and the potassium content would promote a risk- what can be administered

A

a sodium salt of PCN G or a similar medication such as ampicillin or carbenicillin

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8
Q

anuria increases penicillin G by how many fold

A

10 fold

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9
Q

Slide 36

A

Slide 36

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10
Q

Major Resistance to PCN:

A

Bacterial produces B-lactamase enzymes

The hydrolyzed the B-lactam ring rendering it inactive

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11
Q

Drugs not susceptible to hydrolysis by staphylococcal penicillinases that would otherwise hydrolyze the cyclic amide bond of the B-lactam ring and render the antimicrobial inactive:

A
Methicillin
Oxacillin
Nafcillin
Cloxacillin
Dicloxacillin
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12
Q

Specific indications for these drugs are infections caused by staphylococci known to produce the staphylococcal penicillinases enzyme:

A
Methicillin
Oxacillin
Nafcillin
Cloxacillin
Dicloxacillin
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13
Q

what is nafcillin used for

A

Nafcillin can penetrate the CNS sufficient enough to treat staphylococcal meningitis

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14
Q

Extensive renal excretion for what three drugs

A

Methicillin
Oxacillin
cloxacillin

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15
Q

High dose Oxacillin therapy has been associated with

A

hepatitis

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16
Q

what can accompany Methicillin administration:

A

hemorrhagic cystitis and an allergic interstitial nephritis (hematuria, proteinuria)

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17
Q

what two drugs have superseded methicillin

A

oxacillin and nafcillin

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18
Q

what is the advantage of high dose therapy of nafcillin for patients with renal impairment

A

80% is excreted in the bile

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19
Q

unlike methicillin, oxacillin and nafcillin are relative stable in an acidic medium and adequately works in what form

A

PO form

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20
Q

what two drugs are available as PO medications and may be preferable over oxacillin and nafcillin d/t its ability to produce higher blood levels

A

cloxacillin and dicloxacillin

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21
Q

2nd generation PCN

A

ampicillin, amoxicillin and carbenicillin

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22
Q

2nd generation PCN- ampicillin, amoxicillin and carbenicillin. bactericidal against what bacteria?

A

Bactericidal against both gram positive and gram negative bacteria

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23
Q

what generation of abx provide wider range of activity than other PCNs

A

ampicillin, amoxicillin and carbenicillin 2nd gen

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24
Q

which drugs are not effective against most staphylococcal infections

A

2nd generation PCN

ampicillin, amoxicillin and carbenicillin

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25
Q

which drug has a broader ranger than PCN G

A

ampicillin

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26
Q

what does ampicillin cover

A

pneumocci, meningococci, gonococci, and various streptococci

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27
Q

what gram negative bacilli does ampicillin cover

A

Haemophilus influenza and Escherichia coli

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28
Q

is ampicillin well absorbed in the GI

A

Yes

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29
Q

in the first 6 hours of a PO dose of ampicillin how much is excreted unchanged by the kidneys

A

50%

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30
Q

ampicillin is among PCN’s associated with the highest incidence of ““This”” which typically appears 7-10dyas after initiation therapy

A

skin rash

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31
Q

the rash from ampicillin may not be true allergic reaction - what is it more associated with

A

protein impurities in commercial preparation

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32
Q

amoxicillin is chemically identical to what drug

A

ampicillin

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33
Q

even though amoxicillin and ampicillin are chemically identical- what is the advantage of amoxicillin

A

more efficiently absorbed from GI

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34
Q

concentrations of amoxicillin are present in the circulation how many times as long as ampicillin

A

2x’s

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35
Q

what generation is carbenicillin and what is it derived from

A

3rd generation

derivative of ampicillin

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36
Q

the principle advantage of carbenicillin is its effectiveness in Tx of infections cause by what

A

pseudomonas aerugingsa and certain proteus strains resistant to ampicillin

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37
Q

carbenicillin is penicillinase (b-lactamase) susceptible and ineffective against most strains of

A

s. Aureus.

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38
Q

is carbenicillin aborbed from the GI tract

A

NO- must be administered parentally

39
Q

what does probenecid do to the plasma concentration of carbenicillin

A

delays renal excretion thus increases plasma concentration of carbenicillin by 50%

40
Q

greater than 10% of carbenicillin is sodium (30-40g) - in light of this, what can develop in susceptible patient

A

CHF dt this acute drug produced sodium load.

41
Q

what acid base imbalance and electrolyte imbalance may occur with carbenicillin

A

Hypokalemia and metabolic alkalosis may occur d/t obligatory excretion of K+ with the large amounts of nonreabsorbable carbenicillin

42
Q

what is the effect for platelets and carbenicillin

A

Interferes with normal platelet aggregation and prolongs bleeding time even when platelet count remains the same.

43
Q

4th generation PCN

A

Acylaminopenicillins:
Mezlocillin
Piperacillin
Azlocillin

44
Q

4th generation abx are derivatives of

A

ampicillin

45
Q

what generation abx is the broadest spectrum abx of all PCN

A

4th generation

46
Q

how do the sodium contents of 4th generation abx compare to the sodium content of carboxypenicillins

A

lower sodium concentrations but similar side effects

47
Q

what are 4th generation PCN ineffective against

A

penicillinase-producing strains of S. AUREUS

48
Q

PENICILLIN BETA-LACTAMASE INHIBITOR COMBINATIONS name the three drugs

A

clavulanic acid
sulbactam
tazobactam

49
Q

what is special about these three drugs clavulanic acid
sulbactam
tazobactam

A

beta lactam compounds that bind irreversibly to beta lactase enzyme- very little antimicrobial activity

50
Q

clavulanic acid is available with what PO drug

A

po amoxicillin

51
Q

sulbactam is combined with

A

IV ampicillin.

52
Q

cephalosporins are bactericidal and what do they inhibit

A

bacterial cell wall synthesis and have low intrinsic toxicity

53
Q

bacteria can produce cephalosporinases (beta-lactamases) which does what to the beta lactate structure of cephalosporins

A

disrupts it

54
Q

newer cephalosporins have broad spectrums but the issue is

A

they are expensive

55
Q

what are the three things cephalosporins vary in

A

Vary in oral absorption
Vary in the severity of pain at IM site
Vary in protein binding

56
Q

what can IV administration of any cephalosporin cause

A

thrombophlebitis

57
Q

diacetyl metabolites produced by cephalosporins are associated with what?

A

decreased antimicrobial activity

58
Q

large doses of cephalosporins frequently cause what reaction

A

a positive coombs reaction, hemolysis is rare

59
Q

With the exception of cephaloridine, cephalosporins have less frequency of what.

A

With the exception of cephaloridine, cephalosporins have less frequency of nephrotoxicity than aminoglycosides or polymyxins.

60
Q

if allergic to cephalosporins cross-reactivity occurs- does it occur with PCN

A

Cross-reactivity between cephalosporin and PCN are infrequent.

61
Q

if you have a PCN allergy what can be used as an alternative

A

cephalosporins may be used as an alternative

62
Q

CEPHALOSPORINS AND PCN ALLERGIES less often but more serious - mediated by IgE characterized by what three symptom

A

laryngeal edema
bronchospasm
CV collapse

63
Q

PCN allergy can occur more commonly with parental or more than with oral administration?

A

parenteral administeration

64
Q

what does the ring structure of a PCN open to form

A

Hapten metabolite: Penicilloyl

65
Q

what do Hapten Act as

A

an antigen

66
Q

can a hapten induce formation of antibodies? what does it do?

A

no formation of antibodies but bound to a protein may cause an immune response

67
Q

what allergic issue do 95% of patients allergic to PCN form

A

penicilloyl-protein conjugate

68
Q

how do we detect those who would have an allergic reaction to PCN

A

skin test with penicilloyl-polylysine antigen

69
Q

are minor antigenic reactions detected by the skin test with penicilloyl polylysine antigen

A

no- but patients could still develop severe allergic reactions

70
Q

cephalosproins- Classified as 1st, 2nd, 3rd (4th, 5th) generations d/t what

A

antimicrobial spectrum

71
Q

as the cephalosporins increase from 1st to 3rd generation- how does their against against various cocci change

A

Generally activity against gram + cocci decreases and activity against gram – cocci increases

72
Q

what is the appeal of 1st generation cephalosporins

A

inexpensive and exhibit low toxicity

73
Q

1st generation cephalosporins are commonly used as prophylaxis in patients under going surgeries such as

A
CV
Orthopedic
Biliary
Pelvic
Intraabdominal
74
Q

1st generation cephalosporins are as active as 2nd and 3rd generation cephalosporins against what bacteria

A

staphylococci and nonenterococcal streptococci

75
Q

what is the prototype cephalosporin

A

cephalothin

76
Q

tell me about PO, IM, IV absorption of cephalothin

A

PO-poorly absorbed
IM-painful
IV- commonly administered

77
Q

what is the limitation of cephalothin

A

does not enter CSF- not recommended for meningitis

78
Q

does cephalothin need to be decreased in renal patients

A

excreted largely unaltered by kidneys, decrease dose in renal patients

79
Q

cefazolin what is the advantage of this drug

A

Has advantage of achieving higher blood levels, presumably d/t slower renal elimination

80
Q

what is the drug of choice for surgical prophylaxis

A

cefazolin

81
Q

how is cefazolin tolerated

A

well after IM or IV injection

82
Q

2nd GENERATION CEPHALOSPORINS

cefoxitin and cefamandole have extended activity against what bacteria

A

gram negative bacteria

83
Q

Cefoxitin is resistant to _____produced by gram negative bacteria

A

cephalosporinases

84
Q

Cefamandole- pharmacologically similar to cefoxitin but what are the risk with concurrent use of ETOH

A

risk of bleeding and disulfiram like reactions

85
Q

cefuroxime is the only 2nd generation effective in treatment of

A

meningitis

86
Q

cefurozime is more effective than cefamandole against

A

h. influenza

87
Q

3rd generation cephalosporins have enhanced ability to resist hydrolysis by the beta-lactamases of many gram-negative bacilli including

A

E. coli, Klebsiella, Proteus, and H. influenza

88
Q

3rd generation cephalosporins can achieve therapeutic levels in the cerebrospinal fluid meaning it can treat

A

treat meningitis

89
Q

does 3rd generation have to same toxicity as older cephalosporins

A

yes

90
Q

what drug has the longest elimination 1/2 time of any 3rd generation

A

ceftriaxone

91
Q

ceftriazone is highly effective against gram negative bacilli name 2

A

neisseria

haemophilus

92
Q

name the 3rd generation effective PO medication

A

cefixime

93
Q

cefixime is active against

A

pneumococci
group a streptococci
h influenza

94
Q

Cefixime is less effective against s aureus and not active against anaerobes such as

A

pseudomonas