FOM Antibiotics Flashcards
(137 cards)
1
Q
Name the Beta-Lactams
Bactericidal vs bacteristatic
A
Penicillins, Cephalosporins, Carbapenems, Azteronam
bactericidal
2
Q
What are Penicillin Binding Proteins
A
Transpeptidases that catalyze cell wall synthesis
3
Q
What site do penicillins occupy on PBPs? What does this do?
A
D-alanyl-D-alanine
Block cell wall synthesis leading to an increase in cell wall precursors and autolytic enzymes. In hypotonic solutions, the cell will swell and burst.
4
Q
What type of clearance does penicillin have?
A
Renal
5
Q
Penicillin Spectrum?
A
Gram (+) & Few Gram (-)
6
Q
What is Penicillin administered with to increase its half-life and how does it work?
A
Probenecid - impairs renal secretion of weak acids
7
Q
Penicillin in high doses causes what reaction?
A
seizures
8
Q
Oral Penicillin
A
Penicillin V
9
Q
IV penicillin
A
Penicillin G
10
Q
What is benzathine? Describe administration and side effects.
A
Long acting form of Penicillin
IM administration for slow absorbance
Irritation and Local Pain
11
Q
Penicillin side effects
A
Hypersensitivity (rash -> anaphylaxis)
Seizures (crosses BBB)
Nausea
Diarrhea
12
Q
List Penicillinase Resistant Penicillins (Structural Change) and how they are resistant
A
Nafcillin, Dicloxacillin, and Methicillin (no longer used)
larger R-groups so that penicillinases cannot inhibit
13
Q
Penicillinase Resistant Penicillin (structural change) spectrum?
A
MSSA (methicillin susceptible Staphylococcus Aureus)
14
Q
List Penicillinase Resistant Penicillins (inhibitors) and how they are resistant
A
Clavulanate (Taken in Combination with Penicillin because binds irreversibly with penicillinase allowing penicillin to be an effective drug)
Sublactam
Tazobactam
15
Q
List Aminopenicillins and the Penicillinase Resistant Penicillins they are administered with
A
Ampicillin (+ Sublactam)
Amoxicillin (+Clavulanate)
16
Q
Describe Aminopenicillins (including spectrum and mode of action)
A
Penicillinase susceptible, works on Gram (-) bacteria which are intrinsically resistant to penicillin due double membrane/decreased uptake
Aminopenicillins are water soluble and pass through porin channels
H. Influenza, E. Coli, Lysteria, Salmonella
17
Q
List Antipseudomonals and the PRP’s they are administered with
A
Ticarcillin (+clavulanate)
Piperacillin (+tazobactam)
18
Q
Antipseudomonal spectrum
A
Broad activity of both gram positive and gram negative including gram (-) bacilli
Pseudomonas
19
Q
Which Beta-lactams are penicillinase susceptible
A
Penicillin V, Penicillin G, Benzathine, Ampicillin, Amoxicillin, Ticarcillin, Pipercillin
20
Q
Which Beta-lactams are extended spectrum Beta-lactamase sensitive
A
Aztreonam, Cephalosporins
21
Q
Which Beta-lactams are cephalosporinase sensitive?
A
Cephalosporins
22
Q
Which Beta-lactams are Carbapenemase susceptible?
A
Carbapenems
23
Q
Ampicillin is associated with which condition?
A
Pseudomembranous Colitis
24
Q
Which antibiotic should be used for penicillin all penicillin allergies?
A
Aztreonam
25
What causes a pencillin allergic reaction in patients?
Formation of a hapten-protein from B-lactams combining with patient's proteins and stimulating an immune response
26
How common is penicillin induced anaphylaxis?
0.05% of the population
27
How do beta-lactamases work?
Inhibit the beta-lactam ring
28
What are subcategories of Beta-lactamases?
cephalosporinases, penicillinases, carbapenimases
29
What are extended spectrum beta-lactamases?
recognize most beta-lactams and are common in gram negative bacteria
30
What antibiotic can be used for patients with a mild penicillin allergy?
Cephalosporinase
31
What is the structure of Aztreonam?
monocyclic beta-lactam
32
What is Aztreonam's spectrum?
Gram negative rods
| klebsiella, pseudomonas, serratia
33
What are cephalosporins susceptible to?
cephalosporinases and extended spectrum beta lactamases
34
What is aztreonam susceptible to?
extended spectrum beta-lactamases
35
In what format is cephalosporin administered?
oral
36
where are cephalosporins excreted?
kidney
37
Describe 1st generation cephalosporins
Cephlexin
Gram (+) cocci
surgical prophylaxis
don't use for CNS infections - crosses BBB
38
Describe 2nd generation cephalosporins
Cefoxitin
Gram (-) activity (limited Gram (+) activity)
use immediately prior to surgery to prevent infection
doesn't cross BBB
inhibits clotting factors and can prolong bleeding
causes disulfram-like (hangover) symptoms when co-administered with ethanol
39
Describe 3rd generation cephalosporins
Ceftriaxone
streptococci and more serious gram (-) infections resistant to other beta-lactams
crosses BBB
used in meningitis
interacts with calcium containing medications to form crystals that precipitate in the lungs and kidneys
40
Describe 4th generation cephalosporins
cefepime
broadest spectrum
gram (+) & (-) including pseudomonas
41
Describe 5th generation cephalosporins
ceftaroline
binds to penicillin binding protein 2a present in MRSA which has low affinity for other beta-lactams
hospital acquired pneumonia
acute bacterial skin infections
42
Name the carbapenems
Imipenem/Cilastatin (administered together)
| meropenem
43
Why are imipenem and cilastatin always adminstered together?
imipenem can be broken down to a toxic nephrotoxic metabolite
cilastatin prevents this break down by decreasing cleavage of the B-lactam ring by renal dehydropeptidase
44
Carbapenem Spectrum
broad spectrum
| MRSA is resistant
45
Carbapenem is administered...
parenterally
46
What are possible side effects:
With renal dysfunction: seizures
| GI distress can occur
47
Resistance to Carbapenem?
Carbapenemase
Klebsiella pneumonia transmits carbapenemase through horizontal gene transfer and is spreading across the country. The plasmid contains genes knocking out aminoglycosides, fluorquinolines, bactrim
48
List non beta-lactam cell wall synthesis inhibitors
Vancomycin, bacitracin, polymixin B, Daptomycin
49
Vancomycin mechanism
binds D-alanyl-D-alanine terminus of cell wall precursor and inhibits release from the bactophrenol carrier
prevents transglycosylase reaction and cell wall synthesis
50
Vancomycin spectrum
gram positive -- NARROW
| MRSA & c. diff
51
Vancomycin absorption
poor absorption: oral vanco should only be used for c. diff
52
Vancomycin side effects
red man syndrome (hypersensitivity)
nephrotoxicity
dosage adjusted in renal insufficiency
53
Vancomycin resistance
Enterococci
replaces alanine with serine or lactate to prevent binding
some staphylococci have learned vanco-resistance
54
Bacitracin mechanism
prevents dephosphorylation of bactophrenol carrier needed for elongation
cell wall precursors aren't flipped out of the cytosol
55
Bacitracin is administered...
topical opthalmic and derm preps
| poor bioavailability
56
Bacitracin side effects
nephrotoxic when given IM
57
Bacitracin Resistance
Resistance is rare
58
Polymixin B Mechanism
binds to LPS in the membrane and creates holes which release cell contents
59
Polymixin B Spectrum
Multidrug Gram negative Bacilli
pseudomonas aeruginosa
klebsiella pneumoniae
Used in combo with other antibiotics to facilitate entry
60
Polymixin B side effects
severe nephrotoxicity
61
Polymixin B resistance
infrequent to develop resistance and no cross-resistance
62
Daptomycin Mechanism
binds to the cell membrane, aggregates, membrane depolarizes, cell dies
63
Daptomycin Spectrum
gram-positive organism
| vanco resistant and MRSA
64
Daptomycin side effects
pneumonia binds pulmonary surfactant and accumulates in pulmonary spaces
65
Daptomycin Resistance
addition of a positive charged lysine to the cell surface repels the positively charged drug
66
Rifampin Mechanism
Bactericidal
| binds bacterial RNA Polymerase abd block mRNA elongation
67
Rifampin spectrum
mycobacteria TB
68
Rifampin resistance
intrinsic: drug can't bind the beta subunit of RNA-P
acquired: mutations in rpoB gene
69
Rifampin side effects
GI
metabolite turns body fluids orange
CYP3A4 induces metabolism of other medicine leading to organ rejection, seizure loss of control, and risk of pregnancy
70
Fidoxamicin mechanism
bactericidal inhibits RNA P
71
Fidoxamicin spectrum
gram positive anaerobes (c. diff)
72
Fidoxamicin side effects
few due to low absorption
73
Fidoxamicin resistance
point mutations in RNA-P
74
Fluoroquinolones List
ciprofloxacin, levofloxacin, moxifloxacin
75
Fluoroquinolones mechanism
bactericidal
creates DS breaks
bind and inhibit topoisomerase II (gram -) and IV (Gram + -- during mitosis)
76
Fluoro spectrum
gram (+) & (-) and mycoplasma
77
fluoro is prescribed for....
hospital acquired pneumonia
| UTI
78
fluoro resistance
overprescribed
active drug efflux
mutations in topoisomerase
79
Ciprofloxacin public use
biological warfare
80
Fluoro side effects
GI
confusion
C. diff and Candida vaginitis
contraindicated in pregnant and breasting feeding women as well as children (arthoropathy)
81
fluoro should not be taken with...
chelates cations so don't take with calcium, aluminum, iron, and zinc
avoid dairy products
82
Sulfondamide list
sulfamethoxazole, sulfisoxazole
83
Sulfonamide spectrum and action
acts on bacteria/fungi/protozoa that make their own FH4
bacteriostatic
PABA analog and competitively inhibits dihydropteroate synthetase
84
sulfonamide resistance
change dihydropteroate synthase, increase PABA, increase drug effluxf
85
Sulfonamide side effects
hypersensitivity: rash, cross reaction
crystalluria leading to acute renal failure
hemolysis of RBCs if G6P dehydrogenase is deficient
kernicterus: neurologic condition where sulfonamides compete for albumin in newborns causing bilirubin buildup in the brain
86
Trimethoprim mechanism
```
bacteriostatic
inhibits DHFR (dihydrofolate reductase)
```
87
trimethoprim resistance
altered DHFR, increased DHFR, alternative metabolic pathway
88
trimethoprim side effects
GI
89
What is Bactrin and what is the mechanism?
Trimethoprim & sulfamethoxazole
| bactericidal
90
Bactrin treats...
UTI, pneumocystis
91
Metronidazole mechanism
bactericidal
| when it is reduced, it generates free radicals leading to DS breaks and cell death
92
Metronidazole spectrum
anaerobic bacteria
93
Metronidazole resistance
down regulation of pyruvate:ferredoxin oxidoreductase that reduces metronidazole to its toxic radical state
94
Metronidazole side effects
nausea, diarrhea, headache, metallic taste
avoid during pregnancy
disulfram-like reaction with alcohol
build up of acetaldehyde due to inhibition of acetaldehyde dehydrogenase
95
Nitrofurantoin mechanism
bactericidal
reduced by bacterial flavoproteins to reactive intermediates which inactivate or alter bacterial ribosome proteins to inhibit DNA, RNA, protein, and cell wall synthesis
96
Nitrofurantoin spectrum
broad
| rapidly excreted so used for UTI's
97
Nitrofurantoin resistance
no resistance because it inhibits so many different mechanisms
98
nitrofurantoin adverse effects
vomiting and rash
99
Oxazolidinone main antibiotic
Linezolid
100
Linezolid Mechanism
Bacteriostatic
Binds 50S ribosome at the P-site
Binds 23S rRNA & inhibits the initiation complex
101
Linezolid Spectrum
Gram (+)
| MRSA and Vancomycin Resistant Enterococci
102
Linezolid Resistance
Mutation in 23S rRNA
| Not much cross resistance because of its unique binding site
103
Linezolid Side Effects
Bone Marrow Suppression
Inhibits Monoamine Oxidase which can lead to Serotonin Syndrome if taken with Selective Serotonin Reuptake Inhibitor (SSRI).
- SYMPTOMS: anxiety, hallucinations, nausea, increased heartbeat
104
List the aminoglycoides
Gentamicin, Tobramycin, Amikacin
105
Aminoglycoside mechanism & discuss their ability to enter the cell
Bactericidal
Binds 30S Ribosomal Subunit
Inhibits initiation, increase mRNA misreading, induces early termination
NEEDS ATP to get into the cell --> aminoglycosides are cations and polar so they don't cross the PM well. Additionally, they cannot enter the CSF
106
Aminoglycoside Spectrum
Broad Spectrum
107
Aminoglycoside Resistance
Intrinsic: Aminoglycosides cannot cross the PM in anaerobes and in high pH environments -- must be administered with cell wall synthesis attacking antibiotics
Acquired: adenylation, phosphorylation, or acetylation of aminoglycosides for inactivation
108
Amikacin Resistance
Are immune to enzymatic inactivation and are a broader spectrum than most other aminoglycosides (can be used for pseudomonas infections)
109
Aminoglycoside Side Effects
Tubular Necrosis
Nephrotoxic (should not be given with vancomycin or loop diuretics)
Ototoxicity - vestibular and auditory disfunction
Pregnancy Class D (deafness in fetus)
110
List the Tetracyclines
Tetracycline, Doxycycline, minocycline, demeclocycline
111
Concentration Dependent Antibiotics
Aminoglycosides, fluoroquinolones
112
Time Dependent Antibiotics
Beta-lactams, vancomycin
113
Describe the Persister Phenotype
Drug tolerance distinct from resistance
Genetically homogenous forms of bacteria shift between phenotypes
Go into hibernation phenotype while the drug is being administered
114
Tetracycline Mechanism
Bacteriostatic
Binds the 30S ribosome at the A-site
prevent attachment of aa-tRNA
115
Tetracycline Spectrum
Broad including H. Pylori, B. Burgdorferi, chlamydia, mycoplasma
116
Tetracycline Resistance
Increased Efflux
| Ribosomal Protection Proteins block the A-site so tetracyclines can't bind
117
Tetracycline Side Effects
Forms stable chelates with Al, Mg, Fe, & Ca
should be taken without food
GI
phototherapy sensitive
teeth discoloration and inhibition of long bone growth in children
pregnancy class D
118
Chloramphenicol Mechanism
Bacteriostatic
| Binds 50S and inhibits peptidyltransferase and peptide bond formation
119
Chloramphenicol Spectrum
Broad but limited use due to side effects
120
Chloramphenicol Resistance
Inactivated by acetyltransferases
| Decreased membrane permeability
121
Chloramphenicol Side Effects
Bone marrow depression
aplastic anemia
Gray Baby Syndrome (infants don't have glucuronidyl transferase or hepatic enzymes leading to high levels of drug accumulation -- cardiovascular and respiratory collapse)
122
List the Macrolides
Erythromycin, Azithromycin, Clarithromycin
123
Macrolides Mechanism
Bacteriostatic
Bind 50s P-site (prohibits translocation during elongation)
bind 23s rRNA
124
Macrolides Spectrum
Respiratory pathogens
pharyngitis, pneumonia, otitis media
chlamydia (one dose)
125
Macrolides Resistance
Methylation of 23s rRNA (cross resistance with lincosamides & streptogramins)
increased efflux
hydrolysis by esterases
126
Macrolides Side effects
- GI upset
- Erythromycin and Clarithromycin inhibit CYP3A4 leading to a decrease in drug metabolism and hepatic failure
- clarithromycin - class D pregnancy
- Azithromycin - pyloric stenosis in children under 6 months old
127
What antibiotics should be used to treat mycoplasma?
Levofloxacin, azithromycin, doxycycline
128
what is the regiment for treating lymes disease?
Adults: 10 days of doxycycline
Children: 5 days of doxycycline
129
Lincosamide main antibiotic
Clindamycin
130
Clindamycin Mechanism
Bacteriostatic
Bind 50S P-site (inhibits translocation during elongation)
23s rRNA
131
Clindamycin Spectrum
Gram (+)
include anaerobes
skin infections
acne
132
Clindamycin Resistance
Methylation of 23s rRNA (Cross resistance with macrolides and streptogramins)
Adenylation inactivates
ribosomal mutation
133
Clindamycin Side Effects
GI discomfort, abdominal pain, blood and mucus in stool, diarrhea, superinfection with C. diff, hypersensitivity: rash
134
Streptogramins major antibiotics
Quinupristin, Dalfoprisitin (should be taken together)
135
Streptogramins Mechanism
bactericidal for some organisms
bind 50s P-site (inhibit translocation during elongation)
bind 23s rRNA
136
Streptogramins Resistance
methylation of 23s rRNA (cross resistance with macrolides and clindamycin)
enzyme inactivation
increased efflux
137
Streptogramins side effects
```
inhibit CYP3A4 (can't metabolize -- can lead to renal failure)
arthralgias (joint pain)
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