Antimicrobials and Anesthesiology Flashcards
(118 cards)
1
Q
What are some goals and General Rules concerning antimicrobials?
A
- inhibit microorganism at concentrations that are tolerated by the host.
- seriously ill/immunocompromised: select bactericidal
- Narrow spectrum before broad spectrum or combination therapy to perverse normal flora
2
Q
Antimicrobial surgical prophylaxis
A
- cost effective, broad spectrum
- no more than 1hr before incision
- usually a single dose but may be continue for 48hrs
- no proof a brief course results in resistant organisms
3
Q
What are some things to consider when selecting an antimicrobial?
A
- identification of causative organism
- efficacy depends on drug site (BBB)
- single dose
- route of admin
- duration of treatment
- cost
4
Q
What are some general adverse reactions to antimicrobials?
A
- hypersensitivity reactions
- direct drug toxicity
5
Q
T/F: Hypersensitivity is dose related?
A
FALSE - independent of dose
6
Q
What type of adverse reaction is dose related?
A
Direct drug toxicity
7
Q
What are two special considerations?
A
- Parturient
- Elderly
8
Q
What are some concerns with a parturient patient?
A
- most antimicrobials cross the placenta and enter maternal milk
- teratogenecity: concern with any drug
9
Q
What are some concerns with elderly patients?
A
renal impairment
decreased plasma protein
reduced GI motility and acidity
increased body fat
10
Q
What class is penicillin? Is it a cidal or static?
A
B-lactin, Bactericidal (interferes with the bacterial cell wall by preventing it from joining properly or interfering with an enzyme that keeps the cell wall stable)
11
Q
What organism does penicillin kill?
A
pneumococcal, meningococcal, streptococcal
12
Q
How is penicillin excreted?
A
90% renal
13
Q
Ampicillin
A
wider range of activity, gm- bacilli, highest incidence of rash
14
Q
Amoxicillin
A
more efficiently absorbed from the GI tract than ampicillin
15
Q
What are some adverse reaction of penicillin’s?
A
- hypersensitivity - most common (rash +/or fever, anaphylactic, hemolytic anemia
- cross sensitivity (between penicillin and cephalosporins)
16
Q
Why does cross sensitivity occur between penicillin and cephalosporins?
A
the share a b-lactin ring
17
Q
What class is cephalosporin? Is it a cidal or static?
A
B-lactin, bactericidal (inhibits cell wall synthesis
18
Q
Is cephalosporin a broad or narrow spectrum?
A
broad
19
Q
How is cephalosporin excreted?
A
renal
20
Q
What are adverse reactions of cephalosporin?
A
allergic reactions - rash
anaphylactic reaction 0.02% of treated patients
cross sensitivity between cephalosporins and penicillin
21
Q
What are the three classifications of cephalosporins and give an example in each class.
A
FIrst generation - cefazolin
Second generation - cefoxitin
third generation - cefotaxime
22
Q
What generation of cephalosporin is most commonly used in surgical prophylaxis?
A
first generation - cefazolin
23
Q
What generation(s) of cephalosporin are more specific for gram - ?
A
second and third
24
Q
All cephalosporins penetrate into _____.
A
joints
25
Are aminoglycosides cidal or static?
bactericidal
26
Aminoglycosides are effective for what type of bacteria?
gram -
27
How are aminoglycosides excreted?
renal
28
What is the elimination half time of aminoglycosides?
2-3hr
| increase 20-40 fold with renal failure
29
What are some adverse reaction os aminoglycosides?
ototoxicity
nephrotoxicity
skeletal muscle weakness
prolongs NMB
30
Aminoglycosides: Ototoxicity
- irreversible
- vestibular/auditory dysfunction
- drug induced destruction of vestibular or cochlear sensory hairs
- dose dependent - usually occurs with chronic therapy
31
Aminoglycosides: Nephotoxicity
- accumulate in renal cortex - tubular necrosis
- inability to concentrate urine, proteinuria, and RBC casts
- reversible
32
What aminoglycoside is most nephrotoxic?
neomycin
33
Aminoglycosides: Skeletal weakness
- Can inhibit pre-junctional release of acetylcholine
- decreases post synaptic sensitivity to the neurotransmitter
- myasthenia gravis - uniquely sensitive to weakness
- single dose in healthy patients is no a problem
34
Aminoglycosides: Potentiation of NMB
- high plasma concentration when given IV
- systemic absorption from large volumes of irrigation
- reappearance of NMB in PACU
- NMB properties of lidocaine are enhanced
35
Aminoglycosides: Neostigmine or calcium induced antagonism may be ______ or ______.
incomplete or transient
36
What are some example of aminoglycosides?
Streptomycin & Kanamycin
Gentamicin
Amikacin
Neomycin
37
Streptomycin & Kanamycin
- limited uses
- frequent occurrence of vestibular damage
- ototoxicity
38
Is Gentamicin a broad or narrow antimicrobial?
-broad spectrum
39
What is the toxic level of gentamicin?
>9mcg/ml
40
What aminoglycosides is a derivative of kanamycin?
Amikacin
41
Neomycin is used as an adjunct to what?
hepatic coma
42
Why is neomycin not given IV?
d/t toxic effects
43
Are tetracyclines cidal or static?
bacteriostatic - inhibits bacterial protein synthesis
44
What is the common use of tetracycline?
tx of acne - decreases fatty acid content in of sebum
45
How are tetracyclines excreted?
urine and bile
46
What kind of toxicity can tetracyclines cause?
renal
47
What are some side effects of tetracylines?
- permanent discoloration of teeth
| - phototoxicity
48
How is tetracycline given?
PO only
49
What is another example of tetracycline?
Doxycycline
50
How is doxycycline given?
PO or IV
51
What is the difference in prep between doxycycline and tetracycline?
doxycycline is a longer acting preparation
52
Give an example of macrolides.
Erythromycin
53
Is erythromycin a cidal or static?
its both
54
is erythromycin a broad or narrow spectrum?
narrow ( mostly gm +)
55
How is erythromycin excreted?
bile
56
How is erythromycin metabolized?
cytochrome P-450 system
57
Do you need to alter the does of erythromycin in patients with renal disease?
no
58
What are some adverse reactions of erythromycin?
- GI intolerance - most common
- Delayed gastric emptying
- QT effects - prolonged - torsades
- Thrombophlebitis
* ***check to see if pt is taking a drug that inhibits the P-450 system--if so they will have an increase in free faction of drug
59
What class of drug is clindamycin? cidal or static?
Linomycin, bacteriostatic
60
Clindamycin is more active with ________.
anaerobes
61
What is clindamycin used for?
serious infection in GI tract or female genital tract
62
What disease would you want to decrease the dose w/ clindamycin?
liver
63
What are some side effects of clindamycin?
- pseudomembranous colitis (drug stopped immediately)
- pre and post junctional effects at the NMJ
- not antagonized with anticholinesterases or calcium
- large doses can produce long lasting profound NMB
64
Vancomycin is a derivative of _________
glycopeptide
65
Is vanco a cidal or static?
cidal
66
WHat kind of bacteria is vanco effective?
```
gm+
severe staph infections
streptococcal, enterococcal endocarditis
MRSA
pencillin/cephalosporin allergy
```
67
What is vanco excreted?
renal
68
What is vanco's eliminiation half-time?
6hrs and can be up to 9 days with renal failure pats
69
During what procedures is vanco usually used?
cardiac, orthopedic using prosthetic devices, CSF and shunt related infections
70
What is the dosing for vanco?
10-15mg/kg infused for 60mins
| 1gm mixed in 250ml
71
WHat happens if you infuse vanco too rapidly?
PROFOUND HYPOTENSION
72
Red man syndrom
inteense facial and truncal erythema from histamine release - can occur with rapid or slow infusion
73
What are some other side effects of vanco?
ototoxicity
nephrotoxicity
return of NMB?
74
Are sulfonamides cidal or static?
static
75
WHat are sulfonamides used to treat?
UTI
76
How are sulfonamides excreted/metabolized?
hepatic metabolism with renal excretion
77
What are some sides effects of sulfonamides?
```
skin rash to anaphylaxis
drug fever
hepatotoxicity
acute hemolytic anemia
increase effect of PO anticoags
```
78
Are Polymyxin B and Colistimethate cidal or static?
cidal - effect bacterial cell wall membrane phospholipids
79
What bacteria are effected by polymyxin B and colistimethate?
gm -
used for severe UTI
infections of skin, mucous membranes, eyes and ears
80
How are polymyxin B and colistimethate excreted?
kidneys - can accumulate in renal failure
81
What are some side effects of polymyxin B and colistimethate?
* *Most potent of all antimicrobials in their action at the NMJ
- predominately pre junctional
- can produce skeletal muscle weakness resembling non-depolarizing NMB
- marked potentation of NDNMB
- Neostigmine or calcium do not reliably antagonize this drug
* *HIGHLY nephrotoxic
82
Is metronidazole a cidal or static?
cidal
83
Metronidazole works best on what type of bacteria?
gm - bacilli
84
What kind of infections is metronidazole used for?
CNS infections
abdominal and pelvic sepsis
pseudomembranous colitis
85
Are fluoroquinolones cidal or static?
bactericidal - inhibits enzyme that maintains helical DNA structure
86
Are fluoroquinolones narrow or broad spectrum?
broad
87
What is the elimination half time for fluoroquinolones?
3-8hours
88
What can fluoroquinolones inhibit?
P-450 enzymes
89
How are fluoroquinolones excreted?
renal - through glomerular filtration and renal tubular secretion
90
T/F: When using fluoroquinolones you do not need to decrease the dose in a patient with renal dysfunction.
False - decrease the dose
91
What are sine side effects of fluoroquinolones?
Minimal side effects : Mild GI
92
What are fluoroquinolones used to treat?
useful in the tx of complicated GI and GU infections
93
Give an example of a fluoroquinolone. What is it useful in treating?
Ciprofloxacin. useful in tx of a variety of systemic infections including bone, soft tissue and respiratory tract
94
What is a drug used for TB?
Rifampin
95
Is Rifampin a cidal or static?
bactericidal for myobacteria
96
Rifampin inhibits the growth of what kind of bacteria?
most gm+ and many grm-
97
Is rifampin water soluble or fat soluble?
Fat soluble - allows penetration of tissues including CNS
98
How is rifampin administered? How is it excreted?
Oral or parenteral; excreted in bile and urine
99
T/F: You can develop a resistance to rifampin very quickly.
True
100
What are some side effects of rifampin?
- usually infrequent - high doses can see thrombocytopenia, anemia, hepatitis, fatigue, numbness, skeletal weaknes
- Potent inducer of C P450 system - accelerated metabolism of opioids, NMB agents, warfarin
101
What is an example of an antifungal?
Amphotericin B
102
How is amphotericin B administered?
IV - poor PO excretion
103
How is amphotericin B excreted?
- slow renal excretion - approx 80% of patients treated with this drug renal function is impaired - most recover
- monitor plasma cr levels
104
What are some side effects of amphotericin B?
```
fever, chills, dyspnea, hypotension can occur during infusion
impaired hepatic function
hypokalemia
allergic reactions
seizure
anemia
thrombocytopenia
```
105
What are alternatives for antivirals?
vaccines
106
Viruses
- composed of a nucleic acid core surrounded by a protein containing outer coat
- genome either contains RNA or DNA but never both - classified on this basis
107
What are some examples of antivirals?
```
Acyclovir & Valacyclovir
Vidarabine
Famciclovir
Ganciclovir
Amanatadine
```
108
Acyclovir & Valacyclovir
- antiviral activity limited to herpes viruses
| - excreted by the kidneys
109
Vidarabine
- cytomegalic inclusion disease
- herpes simplex encphalitis
- mutagenic and carcinogenic
110
Famciclovir
acute herpes zoster
111
Ganciclovir
cytomegalovirus
| hematologic toxicity
112
Amantadine
influenza A virus
| renal excretion
113
What are interferons?
- term used to designated glycoproteins produced in response to viral infections
- bind to receptors on host cell membranes and induce the production of enzymes that inhibit viral replication - degradation of viral mRNA
- enhances tumoricidal activities of macrophages
114
What are interferons used to treat?
Chronic hep B
| hep C
115
What are side effects of interferons?
```
flu-like symptoms
hematologic toxicity
depression, irritability
decreased mental concentration
development of autoimmune conditions
rashes, aplopecia
changes in CV, thyroid, hepatic function
```
116
Antivirals for AIDS
- Nucleoside reverse transcriptase inhibitors (NRTIs): imposter
- Nonnucleosides reverse transcriptase inhibitors (NNRTIs) : inhibit function of enzymes used by virus
- Protease inhibitors - binds to HIV protease
- Combination therapy is used in treatment of HIV
117
What are some side effects of antivirals for AIDS?
pancreatitis, hepatotoxicity, lactic acidosis, fat redistribution, increases in serum cholesterol and triglycerides, hpersensitivity
- protease inhibitors
- most all inhibit P-450 system
- ritonavir most potent inhibitor
- large plasma increases in many drugs
118
What are some drug that plasma concentration increases with antivirals for AIDS?
analgesics, lidocaine, antimicrobials, anticonvulsants, anticoagulants, anti emetics, CCB
