Antimicrobials Flashcards
(124 cards)
1
Q
Surgical site infections are ____
A
60% preventable
2
Q
Surgical site infection happens
A
Within 30 days post
1 year post device implantation
3
Q
Surgical site infection can involve
A
Incision
Deep soft tissue
Anatomy opened/manipulated
4
Q
SSI pathogenesis can be _____ or _____
A
Endogenous
Exogenous
5
Q
SSI infections are diagnosed by
A
The surgeon
6
Q
What are some Endogenous risk factors
A
Extremes of age
Obese/poor nutrition
DM
Vascular disease
Tobacco/corticosteroid use
7
Q
Exogenous risk factors include
A
Sterile technique
Foreign bodies & implants
Placement of drains
OR environment
Long surgery >2 hrs/type of surgery
8
Q
Wound classification 1 is
A
Clean
No infection/inflammation
Closed
9
Q
What are the common pathogens for Class 1 (clean)
A
Skin flora
Staphylococci (gram +/ staph aureus)
10
Q
Wound classification 2 is
A
Clean-contaminated
Controlled conditions
No unusual contamination
11
Q
What are the sites for Class 2 infections?
A
Respiratory
GI/GU
12
Q
What are the common pathogens for Class 2 (clean-contamination)?
A
Skin flora
Gram-negative rods
Enterococci
13
Q
Wound classification 3 is
A
Contaminated
Open & fresh
Major break in sterile technique
Major spillage from GI
14
Q
Site of infection for Class 3 (contaminated)
A
Respiratory
GI/GU
15
Q
Common pathogens for class 3 (contaminated)
A
Skin flora
Gram- rod
Enterococci
16
Q
Wound class 4 is
A
Dirty/Infected
Existing clinical infection
Old wound /perforated viscera
17
Q
Site for class 4 (dirty/infected)
A
Any previous sites
18
Q
SCIP-1 measure includes a prophylactic ABX given
A
1 hour prior to surgical incision
19
Q
What is the goal of a patient receiving an ABX 1 hour prior to surgical incision?
A
Bactericidal serum, & tissue levels at time of incision
Progressive increase in infection 1hr
20
Q
Vancomycin or a fluoroquinolone should be
A
Initiated within 2 hours before incision
21
Q
What are characteristics of ABX selection?
A
Narrow spectrum
1st & 2nd generation cephalosporins (effective against gram + staph)
22
Q
Which ABX isn’t recommended as routine?
A
Vancomyci, since there is a risk for ABX resistance & beta-lactam allergy
23
Q
When is vancomycin used?
A
If there is a beta-lactam allergy to clindamycin allergy
24
Q
When should ABX be discontinued?
A
Within 24 hours after surgery end time (increased risk of CDIFF with extended use)
25
ABX should be given
30-60 min prior to skin incision
Less effective if given after application of a tourniquet
26
What groups oof ABX fall under beta-lactams?
PNC (PENAMS)
Cephalosporins
Carbapenems
Monobactams
Carabcephems
27
Beta-Lactams interfere with
Peptidoglycan & cause cell lysis in a hypo/iso osmotic environment (cell wall synthesis)
28
Beta-Lactams inhibit
PNC binding proteins (cross-link cell wall) by PNC & cephalosporins
29
Beta-Lactams have an interference with
Murein hydrolase inhibitors, which leads to destruction of the cell wall
30
Beta-Lactams are considered
Bacterialcidal (kill though cell wall)
31
Gram + are more susceptible to beta lactase because
Gram _ has an additional lipopolysaccharide layer
32
What makes a drug bacterial resistant?
The drug has an inability to access the site of action
Production of beta-lactamases
Altered or new PCN binding protein
Efflux of ABX (active pumps)
Gram _ bacteria
33
Beta-lactamases causes
Hydrolysis of beta lactam ring
34
Anti-staphylococcal PCN include
Nafcillin
Oxacillin
Cloxacillin
Dicloxacillin
35
Penicillianse-producing staphylococci is the same as
Beta-lactamase, just effective against PNC
36
Broad spectrum 2nd generation PNC are
Ampicillin
Amoxicillin
37
Broad spectrum 3rd generation PNC are
Carbenicillin
Ticarcillin
38
Broad spectrum 4th generation PNC are
Piperacillin
39
PNC G is effective against
G+/- cocci
G+ rods
Anaerobes
40
PNC ampicillin & piperacillins should be
Dose adjusted in renal disease
41
Beta-lactamase inhibitors include
Clavulanic acid
Sulbactams
Tazobactam
They bind enzymes & the bacteria becomes sensitive to antimicrobial action
42
Ampicillin, amoxicillin, PNC g & V have
Active mono therapy against Group A streptococci
43
What is the most common drug allergy?
PNC allergy
44
PNC allergy has no
Genetic or inheritable train
45
A PNC allergy has the potential to have a
Cross-sensitivity to other beta-lactams, in which other beta lactase should be avoided
46
1st generation cephalosporins include
Cefazolin
Cephalexin
47
2nd generation cephalosporins include
Cefaclor
Cefotetan
Cefoxitin
Cefurixime
48
3rd generation cephalosporins includes
Cefixime
Cefotaxime
Ceftazidime
Ceftriaxone
49
4th generation cephalosporin
Cefepime
50
MOA for cephalosporins
Bind PNC protein & prevents cross linkage of cell wall
51
Cephalosporin resistance can be due to
Production of cephalosporinase
52
What lab value should be evaluated with a patient on cephalosporins?
Creatinine Clearance
53
What is the drug of choice for surgical prophylaxis?
Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin
54
Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin is susceptible to
Gram + cocci
55
Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin, is resistant tto
G-
56
Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin, as a poor
Ability to cross BBB & into CSF, but does cross the placenta
57
Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin is given with
Metronidazole for colorectal surgery
58
What should be watched when giving Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin?
Kidney function
59
What is the dose of Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin?
1-2 grams IV for <120kg
3grams IV >120kg
60
Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin, should be administered over
3-5 minutes & has a peak of 5 min
61
When should Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin, be administered & repeated?
Administer within 60 minutes
Repeat Q4H until closure
62
What are adverse effects of Cefazolin (Ancef/Kefzol), a 1st genration cephalosporin?
Hypersensitivity
Increases effects of anticoags (heparin/warfarin) & increases risk of Lassie-induced nephrotoxicity
Phlebities & pain
Pregnancy B
Seizure
Steven Johnson Syndrome
Superinfection
Transient elevation in hepatic enzymes
63
4th generation, cefepime (maxipime) is effective against
G+/-
64
With a 4th generation, cefepime (maxipime), there is enhancement in
Resistance against beta-lactamase
65
What is the dose of 4th generation, cefepime (maxipime)?
2 grams IV Q12H
66
What are adverse effects of 4th generation, cefepime (maxipime)?
Superinfection
Hypersensitivity
Increased INR (prolonged tx)
Neurotoxicity
67
Allergy to PNC increases
Likelihood of allergy to a different PNC
Potential for cross reactivity across beta lactase are RARE
68
What is the most important determinant in a beta-lactam cross reactivity?
Side chain group
69
What other option do you have for an ABX without beta lactams reactivity?
Quinolones
Macrolides
BUT you risk reduced effectiveness & increased antimicrobial resistance & higher costs
70
What is an immediate hypersensitivity reaction with beta lactams?
Laryngeal edema
Bronchospasm
CV collapse
Sensitivity may be lost over time
71
What is a delayed hypersensitivity reaction with beta lactams?
Maculopapular rash
Fever
72
Which specific drug is the most common cause of anaphylaxis?
Cefazolin
73
What are examples of Aminoglycosides?
Gentamicin
Tobramycin
Amikacin
Streptomycin
Neomycin
74
What is the MOA of Aminoglycosides?
Interferes with protein (peptide) synthesis during mRNA translation
75
Aminoglycosides have
Poor lipid solubility
76
What is the post ABX effect of ahminoglycosides?
Bactericidal activity continues after serum concentration fail
77
When should ahminoglycosides by avoided?
In patients with MG due to the risk of prolonged NMB (will prolong paralysis
78
Gentamicin, an aminoglycoside dose is
1.5-5mg/kg IV (single dose)
79
Gentamicin, an aminoglycoside administration time & infusion rate
Given within 60 min or procedure start
Infuse over 30-120min
Decrease dose in renal patient
80
Gentamicin, an aminoglycoside interactions
Increases effects of neuromuscular blockers
Increased toxicity risk with loop diuretics
81
Adverse effects of aminoglycosides
Ototoxicity (inner ear)-
vestibular dysfunction
auditory dysfunction
Nephrotoxic
accumulation in renal cortex
acute tubular necrosis
inability to concentrate urine & presence of protein
Skeletal muscle weakness
82
Aminoglycosides inhibit
Prejunctional release of ACh
83
With ahminoglycosides causing skeletal muscle weakness, administer
IV calcium
84
Aminoglycoside hypersensitivity is well-tolerated, but there is a risk for
Allergic contact dermatitis (topical administration)-Neomycin common
85
Macrolides include
Erythromycin
Azithromycin
Clarithromycin
86
What is the MOA of macrolides?
Interferes with protein (peptide) synthesis during mRNA translation
87
Macrolides broad spectrum uses are
Active against some G- bacteria
Are bacteriostatic (-cidal in high doses) against most G+
88
What is the risk of giving Macrolides IV?
Thrombophlebitis
N/V
tinnitus
89
Erythromycin undergoes
Extensive metabolism by CYP-450
90
Azithromycin half life
~68 hrs
91
Adverse effects of Macrolides
Prolonged depolarization & QTc
Risk of torsades & arrhythmias
Diarrhea, nausea, ABD pain
Interacts with effects of anticoags
92
Clindamycin (Cleocin) is apart of the
Lincosamide class
93
What is the MOA of Clindamycin (Cleocin), a lincosamide?
Binds 50s ribosome subunit inhibiting peptide-chain synthesis
94
Distribution of Clindamycin (Cleocin)?
High concentration in bone & urine
Crosses placenta
Minimal levels in CSF
Extended post-ABX effect against some bacteria
95
What is the dosing of Clindamycin (Cleocin)?
600-900mg IV
MUST DILUTE
96
Clindamycin (Cleocin) should infuse over____ & be administered within _____
Infuse over 10-60 min
Administer within 60 min of incision
97
Clindamycin (Cleocin) should be redosed
Q6H until closure
98
Clindamycin (Cleocin) is IV incompatible with
Barbiturates
Calcium glutinate
Many other ABX
99
Adverse effects of Clindamycin (Cleocin)
Neuromuscular blockade (pre & post), not improved by Calcium or anticholinesterases
Increased effects of NMB
Diarrhea, CDIFF, ABD pain, N/V
Thrombophlebitis
100
Most common clindamycin hypersensitivity reaction?
Maculopapular eruptions & skin rash
Reports of SJS & eosinophilia reactions
101
MOA of vancomycin (vancocin)
Tight binding to cell wall precursor blocking glycopeptide formation
Inhibition of cell wall synthesis
102
Vancomycin distribution
Distributes widely in tissue/fluids (not CSF)
103
What should be monitored with a patient taking Vanc
Serum trough= lowest concentration in plasma
Renal function
CBC
104
Dose & administration time of Vanc
10-15 mg/kg IV (MAX 2 gram)
Start within 60-120 min of incision
Infuse over at least 60 min
Minimize histamine release & HOTN
Plasma concentration up to 12H
105
Vancomycin can cause red man syndrome, which
Is due to rapid IV infusion
Histamine release, erythema, pruritus
HOTN, dyspnea
Rare CV toxicity & cardiac arrest
Restart infusion at half of original dose
Give H1 & H2 antag
106
Vancomycin can cause hives, laryngeal edema & wheezing. You should consider
Giving EPI
Discontinue infusion
Assess for hypoxemia
107
What are Vanc warning?
Nephrotoxicity
Ototoxicity
Superinfection
Pregnancy C-IV form, but can take PO
108
What is the MOA of Metronidazole (Flagyl)
Drug diffusion across organism cell membrane
Creates a concentration gradient (more drug in)
Cytotoxic particles break down & destabilize cell
109
What is the dosing of Metronidazole?
500-1,000mg PO & IV
Administer within 60 min of incision
110
Adverse effects of Metronidazole
HA
Nausea/ABD pain
Dry mouth/metallic taste
Bacterial infection
Neurologic disturbances
111
Metronidazole should be avoided when?
With ETOH use
Will cause ABD disturbances, N/V, HA & flushing
112
Fluoroquinolones include
Ciprofloxacin
Moxifloxacin
Levofloxacin
Ofloxacin
113
What is the MOA of Fluoroquinolones?
Inhibits DNA synthesis & promotes DNA breakage
114
What is the dose of Ciprofloxacin (Cipro) & the administration time
400mg IV
Administer 120 min of incision
Give slowly over 60+ min & through a large bore IV
115
Adverse effects of Fluoroquinolones
Bacterial resistance
Gastritis/GI upset
CNS disturbances (dizzy, AMS, neuropathy)
Hepatotoxicity
Tendinopathy, tendon rupture, muscle weakness
QT interval prlongation
116
What are the agents of choice for PEDs?
1st & 2nd generation cephalosporins
Vanc in beta lactam allergy
117
PEDs have the potential for toxicity with what class?
Fluoroquinolones
118
In PEDs, ABX are often
Wight based (<40kg)
119
How long should you apply Chlorhexidine?
2min+ & then repeat
120
What is the toxic reaction of Chlorhexidine?
Corneal toxicity (chemical burn)
Potential for neurotoxicity in neuraxial space
121
Povidone Iodine increases
Iodine solubility
122
Povidone Iodine duration of action & application time
6-8 hrs
Apply for 5 min
123
Toxic reaction of Povidone Iodine
Least risk of corneal toxicity
124
Toxic reaction of Iodine
Increases with high concentrations
Corneal toxicity
Rare local toxicity & allergic reaction (fever & skin eruptions)
