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Pharm Block 3 > antibacterials > Flashcards

antibacterials Flashcards

1
Q

drugs that target cell wall

A

beta-lactams, vancomycin, fosfomycin, bacitracin

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2
Q

general properties of B-lactams

A

bactericidal, activity maximal on growing bacteria, G+ and G-, bind PBPs irreversibly, inhibits transpeptidase activity that catalyzes cell wall cross-links (can result in rapid lysis + stx)

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3
Q

resistance to B-lactams

A

Beta-lactamase, altered PBPs, intrinsic resistance of some G- due to porins

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4
Q

what type of killers are B-lactams?

A

time-dependent: keep drug 4X above MIC for > 50% of total treatment time
have short half life, so more frequent dosing

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5
Q

well distributed (low to CSF except during meningitis), some oral, some IV/IM, renal elimination w/ anion transport, short half-lives

A

penicillins

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6
Q

types of penicillins

A

amoxicillin, ampicillin, penicillin G, penicillin V, piperacillin, ticarcillin, oxacillin

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7
Q

penicillin G & penicillin V

A

V = oral, G = IV/IM
for anaerobes, esp G+ (except B. fragilis)
also for non-B-lactamase-producing G+ (1st line for strep throat), also B. anthracis, s. pneumo, NOT staph or enterococcus
used for syphilis, n. meningitidis

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8
Q

penicillin used for B-lactamase-positive staphylococci

A

oxacillin, “methicillin-type drugs”

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9
Q

drug used for otitis media in otherwise healthy kids

A

amoxicillin

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10
Q

used for B-lactamase-negative G+ bugs (listeria, strep) including enterococcus (UTI)
expanded G- spectrum (includes neisseria, haemophilus, e. coli, salmonella

A

ampicillin, amoxicillin

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11
Q

alternate choice for lyme disease, in kids or pregnant/breast-feeding women

A

amoxicillin

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12
Q

2 uses of ampicillin not found with amoxicillin

A 
meningitis (neisseria, listeria) b/c IV
GI infections (shigella) b/c less orally absorbed
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13
Q

broad G- with some G+ activity, good for some anaerobes if used with clavulanate, anti-pseudomonal, susceptible to B-lactamases

A

ticarcillin

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14
Q

gram-negative spectrum similar to ticarcillin but also with pseudomonas, klebsiella, also ones that are ticarcillin-resistant
often used with B-lactamase inhibitor

A

piperacillin

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15
Q

allergic reactions to B-lactams

A

anaphylaxis, serum sickness, dermatitis, maculopapular rash, fever, diarrhea, enterocolitis, elevated liver enzymes, hemolytic anemia, seizures

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16
Q

excretion metabolism of penicillins

A

mostly renal (80% anionic excretion/20% glomerular filtration), 30% hepatic metabolism

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17
Q

skin test, 90-95% reliable at IDing risk for serious allergic reaction

A

PRE-PEN

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18
Q

penicillin administration

A

some only IV/IM, some oral, generally well-distributed, generally short half-lives, CNS distribution poor but increases with inflamed meninges

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19
Q

slow-release IM forms of penicillin

A

procaine, benzathine penicillin

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20
Q

B-lactamase inhibitors + mechanism

A

clavulanic acid, tazobactam

B-lactam “analogs” that bind irreversibly to B-lactamase

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21
Q

B-lactamase inhibitor works with?

A 
class A B-lactamases, including plasmid-encoded forms
restores utility of some B-lactams (ampicillin, amoxicillin, ticarcillin, piperacillin)
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22
Q

B-lactamase inhibitor combination used for MSSA, E. coli, Klebsiella, Haemophilus

A

amoxicillin + clavulanate

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23
Q

penicillin-resistant strep pneumo cause?

A

changes in PBPs

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24
Q

MRSA resistance cause?

A

acquisition of new PBP2a, encoded by MecA

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25
Q

drug class that’s well-distributed, injection, same mech as penicillin, resistance mechs similar

A

cephalosporins

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26
Q

1st generation cephalosporins use

A

gram positive, staph and strep
NOT for enterococcus, listeria, MRSA or meningitis
used for uncomplicated outpatient skin infections & surgical prophylaxis

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27
Q

1st generation cephalosporins

A

cefazolin, cephalexin

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28
Q

IV/IM, best G+ activity of 1st generation, longer half life (1-2 hours)

A

cefazolin

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29
Q

oral, used for skin, bone/joint, UTIs, respiratory and otitis media. 50 min half life

A

cephalexin

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30
Q

only 2nd generation that penetrates CSF, best for haemophilus, but not best against enterics. good tolerance to G- beta-lactamases

A

cefuroxime

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31
Q

2nd gen not for CNS, good for some anaerobes including B fragilis, good tolerance to G- beta-lactamases

A

cefoxitin

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32
Q

3rd generation, very good for the 3 meningitis types, 1st choice for honorrhea, long half life (6-9 hrs)

A

ceftriaxone

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33
Q

uses of 3rd generation cephalosporins

A

gram-negatives: E. coli, klebsiella, enterobacter, proteus… stable against many G- B-lactamases

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34
Q

most active of 3rd generation against pseudomonas, bad for G+, shorter half life (90 mins)

A

ceftazidime

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35
Q

good CSF penetrance, similar to ceftazidime but more G- coverage (more resistant to type I beta-lactamases). empirical treatment of serious inpatient infections

A

cefepime

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36
Q

NONE of the cephalosporins are good for

A

enterococcus, MRSA, listeria, many stomach bugs

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37
Q

cephalosporins excretion/metabolism

A

renal: glomerular filtration, anion secretion

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38
Q

cephalosporin side effects

A

allergic reactions (cross-rxn with penicillins), N/V diarrhea enterocolitis, hepatocellular damage

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39
Q

ESBLs

A

inactivate penicillins, also 3rd generation cephalosporins, monobactams. use carbapenems

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40
Q

broad spectrum, aerobes and anaerobes, resistant to many B-lactamases including ESBLs. not for C diff, MRSA, E. faecum

A

imipenem

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41
Q

imipenem uses

A

mixed infections, ill-defined infections, non-resoponsive or resistant infections. given with cilastatin to extend half-life

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42
Q

imipenem side effects

A

allergic reactions (cross-rxn with penicillins, cephalosporins), seizures/dizziness/confusion, N/V/diarrhea, superinfection

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43
Q

no allergic cross-rections with B-lactams, used against G- aerobic rods, resistant to many B-lactamases

A

aztreonam

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44
Q

aztreonam side effects

A

seizures, anaphylaxis, EKG changes, cramps, N/V, enterocolitis

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45
Q

glycopeptide, not a B-lactam, bactericidal, inhibits cell wall synthesis

A

vancomycin

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46
Q

vancomycin mech

A

binds to D-Ala-D-Ala end of peptide, interferes with crosslinking and elongation of PG chains

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47
Q

vancomycin uses

A

Gram-positives ONLY: staph including MRSA, strep pneumo, enterococcus, C. diff (2nd choice)

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48
Q

vancomycin administration

A

IV for systemic infections, oral for C diff

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49
Q

1st line treatment for meningitis in adults in children when you do not yet know the organism causing the infection.
what organisms will this treatment cover?

A

3rd generation cephalosporin +vancomycin

this will cover strep pneumo (including cephalosporin-resistant), n. meningitides, and h. influenzae

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50
Q

side effects of vancomycin

A 
narrow therapeutic window
"red man" or "red neck" syndrome (histamine related)
nephrotoxicity
ototoxicity
phlebitis
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51
Q

enolpyruvyl transferase inhibitor

A

fosfomycin

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52
Q

uses of fosfomycin

A

uncomplicated UTIs, caused by E. coli, Enterococcus

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53
Q

side effects of fosfomycin

A

headache, diarrhea, nausea, vaginitis
costly
no cross-resistance with other drugs because of the specific mechanism

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54
Q

polypeptide antibiotic, interferes with cell wall synthesis by interfering with carrier that moves early wall components through cell membrane (MurNAc pentapeptide), gram positive spectrum. how is this drug used/administered?

A

bacitracin

topical use only

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55
Q

side effect of bacitracin?

A

allergic dermatitis

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56
Q

which drugs target the cell membrane?

A

polymixins (polymixin B) and cyclic lipopeptides (daptomycin)

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57
Q

acts as a cationic detergent that binds LPS in the outer membrane of gram-negative bacteria; gram-negative spectrum (including Pseudomonas)

A

polymixin B

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58
Q

side effects of polymixin B

A

few side effects with topical use besides allergies; for systemic use, potential for serious nephrotoxicity and neurotoxicity

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59
Q

antibiotic that binds to bacterial cytoplasmic membrane, causing rapid membrane depolarization; rapidly bactericidal

A

daptomycin

depolarization stops essential metabolic and catabolic steps

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60
Q

uses for daptomycin?

which type of bacteria?

A

gram-positive only!!
used for complicated skin and skin structure infections (staph. aureus-MSSA, MRSA; various step.-pyogenes, agalactiae; enterococcus-vancomycin-susceptible only!)
bacteremia (eg. staph)
NOT for pneumonia

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61
Q

side effects of daptomycin

A

no cross-resistance with other antibacterials
nausea, diarrhea, GI flora alterations
muscle pain and weakness (monitor CPK levels)

62
Q

which antibiotics target nucleic acids?

A

quinolones (norfloxacin, ciprofloxacin, moxifloxacin), nitrofurantoin, rifampin, metronidazole

63
Q

inhibits alpha (and possibly beta) subunit of DNA gyrase, thereby interfering with control of DNA winding (replication and repair); bactericidal

A

quinolones

64
Q

how is the bacterial killing of quinolines best predicted?

A

AUC(24)/MIC; integrated area under curve for 24 hrs

65
Q

what are ways to increase AUC(24)/MIC?

A

more frequent doses
more drug per dose
longer T1/2 drug
drug with better MICs

66
Q

prototype quinolone for urinary infections, effective agains enterobacteriaceae, some pseudomonas aeruginosa, staphylococcus, enterococcus. What issue caused recommendations against using quinolines for 1st line empiric therapy for routine UTIs?

A

norfloxacin

resistance issues

67
Q

this quinolone is useful for infections at many sites; UTIs, infectious diarrhea, bone and joint infections, skin infections

A

ciprofloxacin

68
Q

is ciprofloxacin the best choice quinolone for gram-positive infections?

A

no-ciprofloxacin itself is not the best choice for gram-positive infections; other quinolines have better gram-positive and respiratory activity (ex. moxifloxacin)

69
Q

which quinolones are best for gram-positives?

A

moxifloxacin and levofloxacin

70
Q

uses of ciprofloxacin?

A

chlamydia; (CDC no longer recommends using ciprofloxacin to treat uncomplicated gonorrhea due to widespread resistance)

71
Q

uses of moxifloxacin

A

better gram-positive activity than other quinolones;
used for respiratory infections (community-acquired pneumonia; acute exacerbation of bacterial bronchitis; NOT approved for strep. throat)

72
Q

can quinolones be substituted for each other

A

no-have to pay apptention to approved clinical uses (pathogen, site of infection) local sensitivity patterns, and specific strains.

73
Q

distribution of quinolones

A

many fluorinated drugs are well-distributed (including the CSF but not indicated for meningitis); some (eg. norfloxacin) and the non fluorinated agents achieve therapeutic concentrations only in the urinary tract

74
Q

administration of quinolones

A

oral, some also IV

75
Q

side effects of quinolones

A

nausea, vomiting, abdominal pain, enterocolitis, dizziness, headache, restlessness, depression, rare seizures, rashes (potentially fatal!! STOP drug if rash appears!), EKG irregularities, arrhythmias (prolonged QT interval), peripheral neuropathy, arthropathy, tendon rupture

76
Q

precautions for quinolones

A

use precaution in patients with seizure disorders, pregnant

use in children in cautioned (possible cartilage damage)

77
Q

nitroreductase enyme converts these drugs to reactive comounds (including free radicals) which can damage bacterial DNA

A

nitrofurantoin

78
Q

use for nitrofurantoin

A

urinary tract infections (lower UTI only, not renal) caused by e. coli, enterococcus, staphylococcus

79
Q

side effects of nitrofurantoin

A

nausea, vomiting, diarrhea, hypersensitivity, fever, chills, peripheral neuropathy, acute and chronic pulmonary reactions (can cause irreversible pulmonary fibrosis due to oxygen radicals), acute and chronic liver damage, granulocytopenia, leukopenia, megaloblastic anemia, acute hemolytic anemia (in those with glucose-6-P dehydrogenase deficiency)!!

80
Q

antibiotic that binds to and inhibits bacterial RNA polymerase beta; this inhibits RNA synthesis; bactericidal

A

rifampin

81
Q

uses for rifampin

A

tuberculosis; meningitis prophylaxis caused by n. meningitides or h. influenza type b

82
Q

side effects of rifampin

A 
serious hepatotoxicity (with long-term use)
rifampin strongly induces many enzymes (eg. CYP3A4, 2C9, 2C19, 1A, 2A, 2B) that inactivate other drugs-this can lead to major drug interactions
orange color to urine, saliva, sweat, tears
83
Q

non-competitive inhibitor of RNA polymerase; inhibits RNA synthesis

A

fidaxomicin

84
Q

uses of fidaxomicin and adminitration

A

c. difficile infection (3rd like to metronidazole, vancomycin)
bactericidal
oral administration, poorly absorbed

85
Q

side effects of fidaxomicin

A

GI upset, GI bleeding; very expensive!

86
Q

anaerobes reduce the nitro group of metronidazole; the resulting product damages/disrupts DNA; bactericidal

A

metronidazole

87
Q

uses of metronidazole

A

anaerobes
1st line for c. difficult enterocolitis
h. pylori combination therapy (metronidazole+tetracycline (or amoxicillin)+bismuth subsalicylate)
gardnerella vaginalis (bacterial vaginosis)

88
Q

side effects of metronidazole

A 
nausea, vomiting, anorexia, diarrhea
transient leukopenia, neutropenia
thrombophlebitis after IV infusion
bacterial and fungal super infections (esp. candida)
can cause ethanol intolerance
89
Q

c. difficile enterocolitis (causes, considerations, therapy)

A

can be caused by all antibacterials
consider in all patients with antibacterial drugs in last 2 months
therapy:
metronidazole (1st choice for mild-to-moderate cases)
vancomycin (better for moderate-to-severe cases)
vancomycin + metronidazole (very severe cases)
fidaxomicin
fecal transplant

90
Q

freeze initiation (premature release of ribosome from mRNA)

A

aminoglycosides

91
Q

prevents tRNA from binding

A

tetracycline and chloramphenicol

92
Q

blocks peptide bond formation (peptidyl transferase)

A

chloramphenicol

93
Q

blocks translocation step

A

erythomycin and clindamycin

94
Q

causes misreading of mRNA

A

aminoglycosides

95
Q

protein synthesis inhibitors

A

aminoglycosides (gentamicin, tobramycin, amikacin)
tetracyclines (doxycycline, minocycline)
glycylcycline (tigecycline)
macrolides (erythromycin, clarithromycin, azithromycin)
streptogramins
oxazilidinones (linezolid)
misc. (chloramphenicol, clindamycin)

96
Q

bactericidal, IV/IM/topical; transported into bacterial by energy-requiring aerobic process; bind to several ribosomal sites (30S/50S interface); stops initiation and causes premature release of ribosome from mRNA; causes mRNA misreading

A

Aminoglycosides

97
Q

use of aminoglycosides

A

primarily for gram negative “aerobic” bacilli (enterobacteriaceae, Pseudomonas)
often used in combo with cell wall inhibitors or quinolines (synergism)
poor activity against anaerobes
use restricted to serious infection!
narrow therapeutic window

98
Q

how can aminoglycosides be used to treat gram positive infections?

A

requires drug combinations (staphylococcus, streptococcus, some enterococcus)
use in combo with cell wall inhibitors (B-lactams, vancomycin) to enhance the permeability of aminoglycosides
(but, cannot mix aminoglycosides with B-lactams in vitro; chemical reaction inactivates the aminoglycosides)

99
Q

how to treat Enterococcus bacteremia or endocarditis using aminoglycosides

A

ampicillin + gentamicin

vancomycin + gentamicin

100
Q

what is the post-antibiotic effect?

A

aminoglycosides have a post-antibiotic effect:
sustained activity for several hours after aminoglycoside concentration has dropped below effective levels
less frequent dosing
concentration dependent killing!

101
Q

pharmacokinetics of aminoglycosides and problems related to pharmacokinetics?

A

concentration-dependent killers; problem=toxicity is dose-related; post-antibiotic effect allows for less frequent dosing

102
Q

aminoglycosides to know…

A

gentamicin, tobramycin, amikacin

103
Q

choice agent for gentamicin- and tobramycin-resistant strains

A

amikacin

104
Q

side effects of aminoglycosides

A

narrow therapeutic window
nephrotoxicity (usually reversible)
ototoxicity (mostly irreversible)
neuromuscular blockade

105
Q

transported into the cells by a protein-carrier system; prevent attachment of aminoacyl-tRNA binding to 30S ribosomal subunits; bacteriostatic

A

tetracyclines

106
Q

resistance to tetracyclines

A

drug efflux pump; resistance to one tetracycline often implies resistance to them all (plasmid conferring resistance can easily be transferred

107
Q

uses of tetracyclines

A

preferred agents for “unusual bugs”: rickettsia, Lyme disease (Borrelia), chlamydia, Mycoplasma, Ureaplasma

108
Q

alternative treatment for penicillin G-sensitive syphilis, uncomplicated gonorrhoeae (but, CDC indicates it is not adequate on its own); least affinity for calcium

A

doxycycline

109
Q

alternative treatment for penicillin G-sensistive syphilis; uncomplicated gonorrhea (CDC indicates it is not adequate on its own-2nd line agent used alongside another 2nd-line agent); more calcium binding than doxycycline

A

minocycline

110
Q

administration of tetracyclines

A

oral, parenteral; bind calcium, inhibits tetracycline absorption (so do not take with high calcium foods and antacids, etc!)

111
Q

side effects of tetracyclines

A

gastrointestinal disturbances, including enterocolitis; Candida superinfection in colon; photosensitization with rash; teeth discoloration

112
Q

contraindications for tetracyclines

A

avoid use in children, esp. less than 8 years old because of calcium binding and teeth discoloration; contraindicated in pregnancy

113
Q

glycylcycline; works like tetracyclines but also binds additional unique sites in the ribosomes

A

tigecycline

114
Q

resistance to tigecycine

A

no cross-resistance with other antibacterials including tetracyclines

115
Q

uses of tigecycline

A

skin/skin structure infections; complicated intra-abdominal infections; CAP (community-acquired pneumonia)

116
Q

what organisms can tigecycline be used against?

A 
gram negatives (e. coli, citrobacter, klebsiella, enterobacter, NOT psuedomonas)
gram positives (staphylococcus-MSSA, MRSA; streptococcus)
anaerobes (bacteroides, clostridium perfringens)
117
Q

adverse reactions to tigecycline

A

nausea, vomiting, enterocolitis
other side effects similar to tetracyclines including calcium binding
–>FDA alert: increased risk of death, especially those with serious infections–considered a last line agent when there are no other good choices

118
Q

interferes with binding of aminoacyl-tRNA to 50S ribosomal subunit and inhibits peptide bond formation; mode of resistance?

A

chloramphenicol

resistance: acetylation by CAT

119
Q

chloramphenicol uses and side effects

A

indiscriminate use in 1950s;
generally bacteriostatic (can be cidal for H. influenza, N. meningitidis, strep. pneumo)
broad spectrum of activity;
very serious side effects (causes irreversible shut-down of bone marrow in some patients)–restrict its use only when no other agents are suitable

120
Q

current indications for chloramphenicol

A

meningitis (alternative in those with serious cephalosporin allergies)
brain abscesses

121
Q

side effects of chloramphenicol

A

bone marrow depression–fatal aplastic anemia (1 in 30,000); not necessarily dose-related, can be delayed
grey baby syndrome
optic neuritis and blindness
GI effects including enterocolitis

122
Q

binds to 50S subunit, blocks translocation along ribosomes; bacteriostatic. what drugs are in this class?

A

macrolides
erythromycin
clarithromycin
azithromycin

123
Q

primarily against gram positive; recommended for strep throat in penicillin-allergic patients; also effective against “unusual” or “atypical” bugs (chlamydia, mycoplasma, legionella, bordetella)

A

erythromycin

124
Q

side effects of erythromycin

A

nausea, vomiting (from enhanced GI motility)
inhibits CYP3A metabolism/excretion of many drugs
increases risk of arrythmias and cardiac arrest

125
Q

similar to erythromycin, but better kinetics: less frequent dosing, less GI motility effects, somewhat wider antibacterial spectrum; also has some CV risks (prolongs QT interval)

A

clarithromycin

126
Q

uses of clarithromycin

A 
same as erythromycin (primarily against gram positive; recommended for strep throat in penicillin-allergic patients; also effective against "unusual" or "atypical" bugs (chlamydia, mycoplasma, legionella, bordetella))
plus:
haemophilus influenzae, moraxella
penicillin-resistant strep. pneumoniae
atypical mycobacteria
licensed for helicobacter pylori
127
Q

treatment for h. pylori

A

3-drug combos are becoming the standard:
2 antibacterials: e.g. clarithromycin + amoxicillin
plus and acid blocker
examples:
clarithromycin + amoxacillin + omeprazole
metronidazole + tetracycline + bismuth subsalicylate + PPI

128
Q

very common treatment for outpatient respiratory tract infections; for genital infections (chlamydia)

A

azithromycin

129
Q

CDC updated gonorrheal recommendations

A

ceftriaxione + azithromycin or doxycycline

130
Q

adverse reactions to azithromycin?

A

least GI upset than the other macrocodes; few effects on CYP3A4; cardiac (QT prolongation)

131
Q

binds to 50S ribosomal subunit, blocks translocation along ribosomes; significant cause of c. dif enterocolitis; not a macrolide or ketolide

A

clindamycin

132
Q

uses for clindamycin

A

gram positive cocci (e.g. Strep. and MSSA)
suppresses bacterial toxin production of Strep. and Staph.
many anaerobes including Bacteroides fragilis
NOT for C. difficile

133
Q

side effects of clindamycin

A

GI irritation, diarrhea
antibiotic-associated enterocolitis
hepatotoxicity

134
Q

inhibits protein synthesis; binds to 50S ribosomal subunit, interfering with formation of 70S initiation complex; bacteriostatic for Staph. and Enterococcus

A

linezolid

135
Q

uses of linezolid

A

gram positive spectrum
skin/skin structure infections: VRE: vancomycin-resistant Enterococcus faecuim, Staph. aureus, Strep. group A and B
Strep. pneumo (including multi-drug resistant)
Staph.

136
Q

side effects of linezolid

A

non-selective inhibitor of MAO (many possible drug interactions; avoid foods with tyramine)
diarrhea, superinfection, enterocolitis
headache, nausea/vomiting
bone marrow suppression

137
Q

inhibit folate synthesis

A

anti-folates
sulfonamides (sulfamethoxazole, sulfadiazine)
trimethoprim

138
Q

bacteriostatic; competitive analogs of p-aminobenzoic acid, a precursor in folate synthesis; inhibit the action of dihydropteroate synthase

A

sulfonamides

139
Q

uses of sulfonamides

A

today, most commonly used sulfonamides are combined with other antibacterials

140
Q

used with trimethoprim as part of synergistic combination; best pharmacokinetic match to trimethoprim

A

sulfamethoxazole

141
Q

used topically for infection prevention in burn patients

A

silver sulfadiazine

142
Q

side effects of sulfonamides

A

hypersensitivity (rashes, serum sickness–sunlight (UV) makes rash worse)
GI disturbances
renal damage (crystalluria)
potentiate action of other drugs (inhibit CYP2C9)

143
Q

inhibits folate synthesis in bacteria by competitively inhibiting dihydrofolate reductase; dihydrofolate analog

A

trimethoprim

144
Q

uses of trimethoprim

A

usually in combination with sulfamethoxazole: synergistic effect
2 static drugs = 1 cidal drugs
Trimethoprim + Sulfamethoxazole (TMP/SMX)

145
Q

uses of TMP/SMX

A

first choice empiric therapy for uncomplicated UTIs (cystitis) (enterobacteriaceae, coagulase-negative staph.)
upper respiratory tract, ear infections (h. influenzae, moraxella, strep. pneumoniae)
GI infections (salmonella, shigella)
Pneumocystis jiroveci (1st choice for treatment and prophylaxis)

146
Q

side effects of TMP/SMX

A

all of the sulfonamide side effects (hypersensitivity (rashes, serum sickness–sunlight (UV) makes rash worse)
GI disturbances
renal damage (crystalluria)
potentiate action of other drugs (inhibit CYP2C9))
Trimethoprim adds:
nausea, vomiting, diarrhea, rashes
bone marrow suppression
(trimethoprim side effects especially pronounced with long-term use, e.g. AIDS patients)

147
Q

what are the four categories of antibacterials used?

A

prophylactic (e.g. prevent surgical wound infections)
empiric (organism unknown but syndrome known)
pathogen-directed (pathogen known, but susceptibility not yet known)
susceptibility-guided (both pathogen and susceptibility known

148
Q

example of one common use of empiric therapy for uncomplicated cystitis in non pregnant women

A

1st choice: TMP/SMX
other choices:
nitrofurantoin
fosfomycin

149
Q

what are some reasons for antibacterial failures?

A 
drug choice (susceptibility of the pathogen, site of infection--drug penetration, emergence of resistance, superinfection with another organism)
host factors (do abscesses need draining? is host immune response okay? are there foreign bodies, implants, mechanical devices, indwelling lines?)
150
Q

what are some other factors to consider with antibacterial choices?

A

regional and institutional resistance patterns
patient age
renal and liver function
specific disease states
route of administration (site of infection, drug distribution)

151
Q

drugs for hospital-acquired MRSA (HA-MRSA)

A

vancomycin (IV)
linezolid (HA, oral)
daptomycin (IV)
tigecycine (IV)

152
Q

drugs for community-acquired MRSA (CA-MRSA)

A

linezolid (oral)
doxycycline, minocycline (oral)
clindamycin (oral)
TMP-SMX (oral)

Pharm Block 3 (15 decks)

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