Antimicrobials Flashcards
(164 cards)
1
Q
What are the natural penicillins?
A
Penicillin G
Penicillin V
Penicillin G procaine
Penicillin G benzathine
2
Q
Which natural penicillins should ONLY be given IM?
A
Penicillin G procaine
Penicillin G benzathine
Given IV could kill the patient.
3
Q
What are the aminopenicillins?
A
Amoxicillin
Ampicillin
4
Q
What are the penicillinase-resistant penicillins?
A
Cloxacillin Dicloxacillin Oxacillin Nafcillin Methicillin
5
Q
Which penicillin is an extended spectrum penicillin?
A
Piperacillin
6
Q
What causes penicillin resistance?
A
Beta-lactamase, which binds to the beta-lactam forming an acyl enzyme intermediate which under goes rapid hydrolysis (destroying the drug).
Alteration of the penicillin binding proteins (what penicillin binds to and alters) accounts for resistance among pneumococci, some Haemophilus Flu, and some Neisseria.
7
Q
Penicillin G:
Half-Life, Protein Binding, Route of Excretion
A
HL: 0.5-1.2 hours
PB: 55-65%
RE: Renal
8
Q
Nafcillin:
Half-Life, Protein Binding, Route of Excretion
A
HL: 0.5 hour
PB: 87-90%
RE: Hepatic then renal
9
Q
Ampicillin:
Half-Life, Protein Binding, Route of Excretion
A
HL: 1 hour
PB: 15-25%
RE: Renal
10
Q
Amoxicillin:
Half-Life, Protein Binding, Route of Excretion
A
HL: 1 hour
PB: 17-20%
RE: Renal
11
Q
Piperacillin:
Half-Life, Protein Binding, Route of Excretion
A
HL: 0.5-1.3 hours
PB: 22%
RE: Renal
12
Q
Which categories of bugs are sensitive to penicillins?
A
Gram + cocci Gram + bacilli Gram - bacteria Anaerobic bacteria Spirochetes
13
Q
Penicillin V:
Half-Life, Protein Binding, Route of Excretion
A
HL: 1 hour
PB: 80%
RE: Renal
14
Q
Penicillin G: Dosing Recommendations (based on birthweight)
A
<1.2kg: 25,000-50,000U q12h
Less than one week old 1.2-2kg: 25,000-50,000U q12h >2kg: 25,000-50,000 q8h
Over one week old 1.2-2kg: 25,000-50,000U q8h >2kg: 25,000-50,000u q6h
15
Q
Ampicillin: Dosing Recommendations (based on birthweight)
A
<1.2kg: 25-50mg/kg q12h
Less than one week old: 1.2-2kg: 25-50mg/kg q12h >2kg: 25-50mg/kg q8h
Over one week old: 1.2-2kg: 25-50mg/kg q8h >2kg: 25-50mg/kg q6h
16
Q
Nafcillin: Dosing Recommendations (based on birthweight)
A
<1.2kg: 25mg/kg q12h
Less than one week old: 1.2-2kg: 25mg/kg q12h >2kg: 25mg/kg q8h
Over one week old: 1.2-2kg: 25mg/kg q8h 1.2-2kg: 25-35mg/kg q6h
17
Q
Aminopenicillin: Resistances
A
Anything with beta-lactamases
18
Q
Aminopenicillin: Clearance
A
Kidneys
19
Q
What is Zosyn a combination of?
A
Piperacillin (broad spectrum penicillin) and Tazobactam (beta-lactamase inhibitor)
20
Q
Cephalosporins: Mechanism of Action
A
Interfere with synthesis of peptidoglycan in the bacterial cell wall
21
Q
What does a cephalosporin generation tell you?
A
Its spectrum of microbiologic activity
22
Q
What is the gram coverage progression of cephalosporins?
A
Gen 1 is mostly Gram +, but slowly adds more Gram - coverage as the generations progress.
23
Q
Cephalosporin: Excretion
A
Kidneys (adjust dose with renal insufficiency)
24
Q
Ceftazidime:
Half-life, Protein Binding, Route of Excretion
A
HL: 1.9h
PB: 20%
RE: Renal
25
Cefepime:
| Half-life, Protein Binding, Route of Excretion
HL: 1.5-1.7h
PB: 19%
RE: Renal
26
Cefazolin:
| Half-life, Protein Binding, Route of Excretion
HL: 1.4h
PB: 86%
RE: Renal
27
```
Cefazolin:
Dosing Recommendations (based on birthweight)
```
<1.2kg:
20mg/kg/day q12h
```
Less than one week:
1.2-2kg
20mg/kg/day q12h
>2kg
20mg/kg/day q12h
```
```
Over one week:
1.2-2kg
20mg/kg/day q12h
>2kg
20mg/kg/day q8h
```
28
```
Ceftazidime:
Dosing Recommendations (based on birthweight)
```
<1.2kg:
50mg/kg/day q12h
```
Less than one week:
1.2-2kg
50mg/kg/day q12h
>2kg
50mg/kg/day q8-12h
```
```
Over one week:
1.2-2kg
50mg/kg/day q8h
>2kg
50mg/kg/day q8h
```
29
Vancomycin:
| Half-life, Protein Binding, Route of Excretion
HL: 3.5-10haxed
PB: 25-50%
RE: RENAL
30
Aminoglycosides:
| Mechanism of Action
Binds to phospholipids and proteins on bacterial cell membrane, disturbing and inhibiting protein synthesis.
Once in the cytosol, interacts with mRNA translation and prevents protein synthesis (quality or quantity).
31
Aminoglycosides:
| Four distinct antimicrobial aspects
1. Concentration dependent killing
2. Adaptive resistance
3. Post antibiotic effect
4. Syngerism with other antibiotics
These in combination constitute the rationale for extended-interval dosing
32
Ampicillin:
| Gram Effectiveness
Positive
33
Vancomycin:
| Gram Effectiveness
Positive
34
Gentamicin:
| Gram Effectiveness
Negative
35
Penicillin:
| Gram Effectiveness
Positive
36
Zosyn:
| Gram Effectiveness
Gram negative (is broad spectrum)
37
Meropenem:
| Gram Effectiveness
Gram negative (broad-spectrum)
38
Cefazolin:
| Gram Effectiveness
Positive
39
What's the trade name for cefazolin?
Ancef
40
Cefotaxime:
| Gram Effectiveness
Negative
41
Cefepime:
| Gram Effectiveness
Negative
42
Ampicillin:
Use Against which Bugs?
Which Bug is Resistant?
Streptococcus, LISTERIA, enterococcus (+ gent)
DO NOT USE FOR STAPH
43
Ampicillin:
| Mechanism of Action
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall beath by inhibiting peptidoglycan synthesis.
44
Ampicillin:
| Toxicity
Diarrhea, feeding intolerance, rash
45
Ampicillin:
| Does it cross the blood-brain barrier?
Yes
46
Cefazolin:
| Use Against which Bug?
MSSA - used perioperatively for prophylaxis against staph
47
Cefazolin:
| Which Generation?
First
48
Cefazolin:
| Mechanism of Action
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall beath by inhibiting peptidoglycan synthesis.
49
Cefazolin:
| Toxicity
Phlebitis (rare)
50
Cefazolin:
| Which procedure do we use it most for?
PDA ligation
51
Nafcillin:
| Gram Effectiveness
Positve
52
Nafcillin:
| Use Against which Bugs?
Staph, strep, staph aureus MSSA
Nafcillin is better at killing MSSA than vancomycin, but it's rare the germ has a sensitivity to Nafcillin, so Vanc is used more frequently.
53
Nafcillin:
| Mechanism of Action
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall beath by inhibiting peptidoglycan synthesis.
54
Nafcillin:
| Toxicity
Thrombophlebitis (really nasty on the vessels), leukopenia
55
Nafcillin:
| Does it cross the blood-brain barrier?
Yes, especially with staph in the CSF
56
Nafcillin:
| Metabolism
Liver
57
Penicillin G:
| Use Against which Bugs?
Untreated/inadequately treated maternal SYPHILIS, gonococcal infection, strep
58
Penicillin G:
| Mechanism of Action
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall beath by inhibiting peptidoglycan synthesis.
59
Penicillin G:
| Toxicity
Very rare CNS toxicity, adjust for renal dysfunction
60
Vancomycin:
| Use Against which Bugs?
MRSA, Mec A gene present, coag negative staph
61
Vancomycin:
| Mechanism of Action
Binds D-alanyl-D-alanine blocking peptidoglycan synthesis (inhibits cell wall synthesis)
62
Vancomycin:
| Toxicity
Redman syndrome, flushing, hypotension, ototoxicity, nephrotoxicity
63
Vancomycin:
| Does it cross the blood-brain barrier?
No
64
Vancomycin:
| What is Vanc MIC >=2
Add another abx to help
65
Vancomycin:
| Levels
Peak: 35-45 mcg/mL (2 hours from start)
Trough: 15-20 mcg/mL
66
Vancomycin:
| Where is the killing power?
Trough
67
Rifampin:
| Use Against which Bugs?
Staph - in combination with other antibiotics because bugs gain rapid resistance if used by itself.
68
Rifampin:
| Mechanism of Action
Inhibits bacterial RNA synthesis
69
Rifampin:
| Toxicity
Blood dyscrasia (leukopenia, thrombocytopenia), cholestasis (jaundice, increased LFT, red-orange body fluid)
70
Rifampin:
| Clearance
Hepatically cleared, amplifies cyp-450 (interacts with many medications)
71
Rifampin:
| Does it cross the blood-brain barrier?
Yes
72
Tobramycin:
| Use Against which Bugs?
E. Coli, Enterobacter, pseudomonas, H-flu, Klebsiella, Serratia, other gram - in synergy with amp for CBS and enterococcus.
73
Tobramycin:
| Gram Effectiveness
Negative
74
Tobramycin:
| Mechanism of Action
Binds 30S ribosomal subunits inhibiting protein synthesis, block further translation, causes premature termination and incorporation of incorrect amino acids
75
Tobramycin:
| Toxicity
OTOTOXICITY, nephrotoxicity
76
Tobramycin:
| Does it cross the blood-brain barrier?
Nope
77
Gentamicin:
| Where is the killing power?
Peak (concentration-dependent killing - the higher we go, the higher the killing power)
78
Gentamicin:
| Why do we care about the trough?
Renal dysfunction leading to poor clearance: nephrotoxicity and ototoxicity
79
Gentamicin:
| When to obtain levels with extended dosing?
24 hours after the second dose: based on the volume of distribution and half-life for the postnatal age and gestational age of the infant
80
Gentamicin:
| Issues with Extended Dosing
Large Vd may not yield a high peak
Change to cefotaxime if there are issues with Vd and half-life
If trough <0.3mcg/mL then measure a peak and do first-order kinetics - not sure how long it's been that low
81
Cefotaxime:
| Use Against which Bugs?
Non-Pseudomonal gram-negative rods: E Coli, H flu, Klebsiella
82
Cefotaxime:
| Mechanism of Action
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall death by inhibiting peptidoglycan synthesis.
83
Cefotaxime:
| Toxicity
Local phlebitis, diarrhea, pseudomembranous colitis, thrombocytopenia
84
Cefotaxime:
| Synergy with Ampicillin?
Nope
85
Cefotaxime:
| Does it cross the blood-brain barrier?
Yes
86
Cefotaxime:
| Large or narrow therapeutic window?
Large: can use for large volumes of distribution and crappy clearance
87
Cefotaxime:
| What infection does it increase the risk for?
Fungal infections
88
Cefotaxime:
| Which generation cephalosporin is it?
Third
89
Ceftazidime:
| Gram effectiveness
Negative
90
Ceftazidime:
| Use Against which Bugs?
PSEUDOMONAS, E. Coli, Enterobacter, H flu, Klebsiella, other gram-negative rods
91
Ceftazidime:
| Which generation cephalosporin is it?
Third
92
Ceftazidime:
| Mechanism of Action
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall death by inhibiting peptidoglycan synthesis.
93
Ceftazidime:
| Toxicity
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall death by inhibiting peptidoglycan synthesis.
94
Ceftazidime:
| Does it cross the blood-brain barrier?
Yes
95
Cefepime:
| Gram effectiveness
Negative
96
Cefepime:
| Use Against which Bugs?
P.S.E.U.D.O.M.O.N.A.S (use before ceftazidime), E coli, Enterobacter, Serratia, H flu, Klebsiella, other gram-negative rods
97
Cefepime:
| Mechanism of Action
Interferes with bacterial cell wall synthesis by binding penicillin-binding proteins and causes cell wall death by inhibiting peptidoglycan synthesis.
98
Cefepime:
| Toxicity
Local phlebitis, diarrhea, pseudomembranous colitis, thrombocytopenia
99
Cefepime:
| Does it cross the blood-brain barrier?
Yes
100
Cefepime:
| Which cephalosporin generation?
Fourth
101
Cefepime:
| Amp C-gene
Use in multi-resistance, Pseudomonas Meningitis, Pathogens known to exhibit Amp C gene.
Amp C gene- a chromosomal class C Beta lactamase
Enterobacter and Serratia exhibit Amp C
Pathogens with the Amp C gene can report susceptibilities to Cephalosporins but rapidly grow resistance while being treated. Cefepime is a fourth-generation cephalosporin that has more resistance to Amp C
102
Carbapenems:
| Broad or Narrow Spectrum?
Broad
103
Meropenem:
| Use Against which Bugs?
Multidrug resistant gram negative infections: pseudomonas, Enterobacter
104
Meropenem:
| Mechanism of Action
Inhibits cell wall synthesis by binding PCN-binding proteins
105
Meropenem:
| Toxicity
Pseudomembranous colitis, seizures, diarrhea, false positive Coombs test, HYPOKLAMIEA
106
Meropenem:
| Does it cross the blood-brain barrier?
Yes
107
Zosyn:
| Broad or Narrow Spectrum?
Broad
108
Zosyn:
| Use Against which Bugs?
Drug-resistant gram-negative infection, pseudomonas (also, broad gram-positive and anaerobic coverage)
109
Zosyn:
| Toxicity
Pseudomembranous colitis, increased LFTs, increased BIli
110
Zosyn:
| Drug of Choice for which Infection?
NEC
111
Zosyn:
| Does it cross the blood-brain barrier?
Yes
112
Azithromycin:
| What bug do we use it against and where does it grow from?
Ureaplasma which grows out of tracheal apsirates
113
Azithromycin:
| Mechanism of Action
Binds 50S ribosomal subunits inhibiting protein synthesis
114
Azithromycin:
| Toxicity
Increased LFTs, drug interactions with arrhythmias
115
Amphotericin B:
| Use Against which Bugs?
Fungal infection: Candida
116
Amphotericin B:
| Mechanism of Action
Binds ergosterol altering cell membrane permeability causing leakage of cell components and cell death
117
Amphotericin B:
| Toxicity
Fever, chills, agitation, hypotension, hypokalemia, hypomagnesium, renal failure, renal tubular acidosis, decreased hematocrit, rare thrombocytopenia
118
Amphotericin B:
| Does it cross the blood-brain barrier?
No
119
Amphotericin B:
| How long to give a treatment?
30 days following a negative culture
120
Amphotericin B:
| Caution with serum creatinine
Hold for two days if serum creatinine rises above 0.4mg/dL
121
Amphotericin B:
| Fluid Incompatibility
Not compatible with TPN and is also a four hour infusion time
122
Fluconazole:
| Use Against which Bugs?
Fungal infection: Candida (preferred over amphotericin)
123
Fluconazole:
| Mechanism of Action
Interferes with fungal cytochrome P450 sterol c-14-alpha-demethylation which decreases ergosterol synthesis inhibiting cell membrane formation
124
Fluconazole:
| Toxicity
Feeding intolerance, diarrhea, increased LFTs (less toxic than Amphotericin B)
125
Fluconazole:
| Does it cross the blood-brain barrier?
Yes
126
Fluconazole:
| Metabolism?
Hepatic metabolism - lots of drug interactions
127
Voriconazole:
| Use Against which Bugs?
Refractory fungal infections
128
Voriconazole:
| Mechanism of Action
Interferes with fungal cytochrome P450 sterol c-14-alpha-demethylation which decreases ergosterol synthesis inhibiting cell membrane formation
129
Voriconazole:
| Toxicity
Feeding intolerance, diarrhea, increased LFTs
130
Voriconazole:
| Metabolism
Hepatic P450 interactions
131
Caspofungin:
| Use Against which Bugs?
Refractory fungal infections
132
Caspofungin:
| Mechanism of Action
Inhibits synthesis of beta D-glucan, an essential fungi cell wall component
133
Caspofungin:
| Toxicity
Hypokalemia, hypercalcemia, hepatic impairment, anemia, decreased hemoglobin, neutropenia, bronchospasm
134
Caspofungin:
| How long is the treatment?
30 days
135
Caspofungin:
| Labs to Monitor
LFTs, potassium, CBC (lower hemoglobin)
136
Caspofungin:
| Metabolism
Hepatic
137
Caspofungin:
| Does it cross the blood-brain barrier?
Somewhat
138
Acyclovir:
| Use against what Virus?
Neonatal HERPES or suspected herpes
If meningitis without hypoxia at birth (seizure type activity, consider putting on acyclovir (evidence of herpes), or if lesions are evident (herpes rash).
139
Acyclovir:
| Mechanism of Action
Converted to triphosphate which competes with deoxyguanosine triphosphate for viral DNA polymerase and incorporates into viral DNA, thus inhibiting DNA synthesis
140
Acyclovir:
| Toxicity
Nephrotoxicity (rate-dependent), crystalluria, phlebitis at IV site (concentration dependent)
141
Acyclovir:
| Does it cross the blood-brain barrier?
yes
142
Acyclovir:
| Fluid level to prevent Nephrotoxicity
Baby has to be on 80mL/kg/day to ensure hydrated kidneys
143
Ganciclovir:
| Use Against which Virus?
CMV to decrease hearing loss
144
Ganciclovir:
| Mechanism of Action
Acyclic nucleoside analog of guanine
145
Ganciclovir:
| Toxicity
Anemia, thrombocytopenia, significant NEUTROPENIA IN MAJORITY of patients
If neutropenia issues are present, decrease the dose 50%. If neutropenia does not resolve, then discontinue.
146
Ganciclovir:
| Infusion Considerations
Avoid direct contact with the medication, treat as a cytotoxic drug (DON'T LET PREGNANT WOMEN HANDLE)
Complex infusion with specific tubing and filter
147
Valganciclovir:
| Oral Treatment for Ganciclovir. Treatment course?
60 days at home, and continues to improve hearing at 24 months
148
Valganciclovir:
| Use Against which Virus?
CMV
149
Valganciclovir:
| Mechanism of Action
Prodrug to Ganciclovir (improves bioavailability)
150
Valganciclovir:
| Toxicity
Anemia, thrombocytopenia, neutropenia, bone marrow suppression, potential carcinogen
151
Mother to Child HIV transmission:
| Which Triple Therapy?
Zidovudine
Lamivudine
Raltegravir (if less than 37 weeks then use Nevirapine instead)
152
Zidovudine:
| Use Against?
HIV transmission
153
Zidovudine:
| Mechanism of Action
Converted to a triphosphate which substitutes for deoxythymidine triphosphate for incorporation by reverse transcriptase inhibiting DNA synthesis
154
Zidovudine:
| Toxicity
Anemia, neutropenia (dose-dependent
155
Zidovudine:
| When to Start?
Within 6-12 hours of birth of known HIV exposure.
156
Lamivudine:
| Use Against?
HIV transmission
157
Lamivudine:
| Mechanism of Action
Converted to a triphosphate which substitutes for deoxythymidine triphosphate for incorporation by reverse transcriptase inhibiting DNA synthesis
158
Lamivudine:
| Dose
2 mg/kg PO q12h
| At four weeks, increase to 4 mg/kg PO q12h
159
Raltegravir:
| Use Against?
HIV transmission
160
Raltegravir:
| Mechanism of Action
Integrase inhibitor
161
Raltegravir:
| Benefits
Greater viral suppression and less toxicity than non-nucleoside reverse transcriptase inhibitors in naive adults (not a lot of drug exposures)
162
Raltegravir:
| Contraindications
Less than 37 weeks
163
Raltegravir:
| Toxicity
Increase in LFTs, Hyperglycemia, neutropenia
| RARE: rash, steven-johnson syndrome, and epidermal necrolysis
164
Raltegravir:
| Dose
PNA <8 days: 1.5 mg/kg PO q24h
PNA 8-28 days: 3 mg/kg PO q12h
PNA >28days: 6mg/kg PO q12h
Hold first dose 24-48 hours post-delivery if mom has received this medication within 24 hours of delivery
