Exam 1: Antimicrobials and Antibiotics Flashcards
(107 cards)
1
Q
Class of antibiotic to use in immunocompromised patients:
A
Bactericidal
2
Q
Reason for preserving normal/GI flora if possible:
A
Normal flora have antixenobiological action
3
Q
Type of abx usually used in OR:
A
Cheap, broad spectrum
4
Q
Are abx always necessary in OR?
A
No; pts with allergies and superficial surgeries may not need
5
Q
SCIP guidelines for abx:
A
Single dose within 1 hr of incision
6
Q
Considerations for selection of abx:
A
ID of causative organism
Drug delivery to site
Single drug if possible
Route, duration, cost
7
Q
Pts who particularly need prophylactic abx:
A
Bowel/appy
Hardware
Diabetics
Extended surgical time
8
Q
Relationship between hypersensitivity reaction and dose:
A
Independent
9
Q
Relationship between drug toxicity and dose:
A
Dose related
10
Q
Abx concerns with parturients:
A
Most abx cross the placenta and enter milk
Possible teratogenicity
11
Q
Abx concerns with elderly:
A
Renal impairment
Decreased plasma protein
Reduced GI mobility, acidity
Increased body fat = more drug in tissues
12
Q
Penicillin structure and mechanism of action:
A
Bactericidal beta-lactam
Interferes with bacterial cell wall
13
Q
Organisms susceptible to penicillin:
A
-coccals
Pneumococcal
Meningococcal
Streptococcal
14
Q
Penicillin elimination:
A
Renal
15
Q
Ampicillin organisms:
A
Gram(-)
H. influenza, e. coli
16
Q
Notable ampicillin adverse effect:
A
Skin rash
17
Q
Amoxicillin advantage over ampicillin:
A
More efficiently absorbed from GI tract
18
Q
Most allergenic antimicrobial:
A
Penicillins
19
Q
Most common adverse reaction to PCNs:
A
Allergy/hypersensitivity
20
Q
Signs of PCN allergy:
A
Rash and/or fever
Anaphylaxis
Hemolytic anemia
21
Q
Classes of abx with cross-sensitivity and % chance:
A
PCNs and cephalosporins
8% chance
22
Q
Cephalosporin mechanism of action:
A
Bactericidal
Inhibits bacterial cell wall synthesis
23
Q
Cephalosporin elimination route:
A
40% bile
60% renal
24
Q
Cephalosporin organisms:
A
Broad spectrum
25
Primary s/s of cephalosporin allergy:
Rash
26
% incidence of anaphylactic rxn to cephalosporin:
0.02%
27
First, second, and third generation cephalosporins:
1st: cefazolin
2nd: cefoxitin
3rd: cefotaxime
28
Type of surgery that often uses cephalosporins and why:
Ortho - cephalosporins penetrate into joints
29
Differences in cephalosporin generations:
Better anti-Gm(-) activity in later generations
30
Aminoglycoside mechanism of action:
Bactericidal
| Inhibits cellular activity inside microbe
31
Aminoglycoside organisms:
Aerobic Gm(-)
32
Aminoglycoside elimination & elimination half-time
Extensively renal
2-3hr elimination half-time in healthy pt
20-40x increase in renal failure
33
Aminoglycoside adverse effects:
Ototoxicity
Nephrotoxicity
Skeletal muscle weakness
Prolongs NMB
34
Mechanism of aminoglycoside ototoxicity:
Irreversible damage to vestibular/cochlear hairs
| Dose dependent
35
Mechanism of aminoglycoside nephrotoxicity:
Accumulation in renal cortex --> tubular necrosis --> proteinuria, dilute urine, RBC casts
Reversible!
36
Most nephrotoxic aminoglycoside:
Neomycin (mostly given topical for this reason)
37
Mechanism of aminoglycoside muscle weakness:
Inhibits pre-synaptic ACh release
| Decreases post-synaptic sensitivity to ACh
38
Patient population in whom aminoglycosides should be avoided:
Myasthenia gravis
39
"Sneaky" way aminoglycosides become systemically absorbed:
From irrigation fluid
40
Drug effect enhanced by aminoglycosides:
NM blocking properties of lidocaine
41
Five aminoglycosides:
```
Streptomycin
Kanamycin
Gentamicin
Amikacin
Neomycin
```
42
Toxic level of gentamicin:
> 9mcg/ml
43
Unique use of neomycin:
Adjunct therapy to hepatic coma
44
Aminoglycosides with limited use due to ototoxicity:
Streptomycin/kanamycin
45
Tetracyclines mechanism of action:
Bacteriostatic
| Inhibits bacterial protein synthesis
46
Common use of tetracyclines:
Treatment of acne via decrease in fatty acid content of sebum
47
Tetracyclines elimination:
Excreted in urine and bile
48
Tetracyclines side effects:
Discoloration of teeth (in developing fetus/children)
Photosensitivity
Hepatic/renal damage in high doses
49
Administration of tetracycline:
PO only
50
Administration of doxycycline:
IV or PO
51
Macrolide drugs:
Erythromycin, azithromycin
52
Erythromycin mechanism of action:
Can be bacteriostatic or bactericidal
| Inhibits bacterial protein synthesis
53
Erythromycin organisms:
Gm+ bacteria
| Narrow spectrum
54
Erythromycin elimination:
CYP450 metabolism
| Excreted mostly in bile
55
Erythromycin adverse effects:
GI (esp. IV)
QT effects
Thrombophlebitis (prolonged IV use)
56
Physiologic alteration that increases erythromycin side effects:
CYP450 inhibition
57
Clindamycin class:
Linomycins
58
Clindamycin mechanism of action:
Bacteriostatic
| Inhibits bacterial protein synthesis
59
Clindamycin organisms:
Anaerobes
60
Clindamycin uses:
Serious GI or female genital tract infections
61
Clindamycin dosing considerations:
Decrease dose with severe liver disease
62
Clindamycin adverse effects:
Pseudomembranous colitis
| Pre- and post-synaptic effects at NMJ - unantagonizable with calcium or anticholinesterases
63
Vancomycin class:
Glycopeptide derivative
64
Vancomycin mechanism of action:
Bactericidal
| Impairs cell wall synthesis
65
Vancomycin organisms:
Gm(+) bacteria
Staph
Strepto- and enterococcus
MRSA
66
Vancomycin elimination & elimination half-time:
Renal excretion
6 hrs
Up to 9 days in renal patients
67
Vancomycin surgical uses:
Cardiac procedures
Ortho procedures with prosthetics
CSF, shunt infections
68
Vancomycin dosing & concentration:
10-15 mg/kg over 60 min
| 1gm/250ml concentration
69
Vancomycin adverse effects:
*Profound hypotension with rapid infusion*
Red man syndrome
Ototoxicity/nephrotoxicity
70
Mechanism of red man syndrome:
Facial/truncal erythema from histamine release
71
Sulfonamides mechanism of action:
Bacteriostatic
| Inhibit bacterial folic acid synthesis
72
Sulfonamide uses:
UTIs
73
Sulfonamide elimination:
Hepatic metabolism
| Renal excretion
74
Sulfonamide side effects:
```
Skin rash, anaphylaxis
Drug fever
Hepatotoxicity
Acute hemolytic anemia
Increase PO anticoagulant effect
```
75
Polymixin B/colistimethate mechanism of action:
Bactericidal
| Affects bacterial cell wall phospholipids
76
Polymixin B/colistimethate organisms:
Gm(-) bacteria
77
Polymixin B/colistimethate uses:
Severe UTIs
Skin, mucous membrane, eye, ear infections
GI tract sterilization (poop transplant)
78
Polymixin B/colistimethate elimination:
Renal elimination
79
Polymixin B/colistimethate side effects:
Most potent at NMJ
| Very nephrotoxic
80
Metronidazole mechanism of action:
Bactericidal
81
Metronidazole organisms:
Anaerobic Gm(-) bacteria
82
Metronidazole uses:
CNS infections
Abdominal/pelvic sepsis
Pseudomembranous colitis
83
Fluoroquinolones mechanism of action:
Bactericidal
84
Fluoroquinolones organisms:
Enteric Gm(-) bacilli
85
Fluoroquinolones elimination & elimination half-time:
Mostly renal excretion
| 3-8 hr half-time
86
Fluoroquinolones drug example:
Ciprofloxacin
87
Fluoroquinolones adverse effects:
```
CYP450 inhibition
GI disturbances (mild)
```
88
Fluoroquinolones uses:
Systemic infections, bone, soft tissue, respiratory tract, GI, GU
89
Rifampin mechanism of action:
Bactericidal
| Inhibits RNA chain in microbe
90
Rifampin organisms:
Mycobacteria - tuberculosis
Gm(+) - most
Gm(-) - many
91
Rifampin administration and excretion:
Oral or parenteral
Bile and urine excretion
Penetrates into CNS
92
Rifampin side effects:
```
CYP450 induction
Thrombocytopenia
Anemia
Hepatitis
Fatigue/weakness
Numbness
```
93
Amphotericin B use:
Yeasts and fungi
94
Amphotericin B administration:
IV only
95
Amphotericin B elimination:
Renal - slowly!
96
Amphotericin B adverse effects
```
Renal function impairment (80%!!)
Fever, chills, dyspnea, hypotension
Hepatic impairment
Hypokalemia
Allergies
Seizures
Anemia/thrombocytopenia
```
97
Classification of viruses:
DNA or RNA
98
Acyclivir & valacyclovir use and elimination:
For the herps
| Renal excretion
99
Vidarabine uses and side effects:
Cytomegalic inclusion disease
HSV encephalitis
Mutagenic, carcinogenic
100
Famciclovir use:
Acute herpes zoster
101
Ganciclovir use and adverse effect:
CMV disease
| Hematologic toxicity
102
Amantadine use and elimination:
Influenza A virus and Parkinson's
| Renal excretion
103
Interferons mechanism of action:
Induce enzymes that inhibit viral replication
| Enhance anti-tumor activities of macrophages
104
Interferons uses:
Hepatitis B (chronic)
Hepatitis C
Nasal sprays
105
Interferons side effects:
```
Flulike symptoms
Hematologic toxicity
Depression, irritability, decreased concentration
Autoimmune conditions
Rash, alopecia
CV, thyroid, hepatic changes
```
106
Types of AIDS antivirals:
Nucelotide reverse transcriptase inhibitors
NON-nucleotide reverse transcriptase inhibitors
Protease inhibitors
107
AIDS antiviral side effects:
Pancreatitis, hepatitis, lactic acidosis, fat changes, increased cholesterol/trigs, hypersensitivity
Protease inhibitors are potent CYP450 inhibitors
