Anti-Microbials Flashcards
list the 14 anti pseudomonals
FQs: cipro and levofloxacin
monobactam: aztreonam
carbapenems: all 4 (*imipenem and meropenem)
cephalosporins: ceftazidime, cefepime
Piperacillin, carbenicillin
aminoglycosides: gentamicin, tobramyicn, amikacin
colistin
rx for outpatient w/ no recent AB use
macrolide (G+, H flu, A) or doxy (G+,G-, A)
preferred macrolide for H flu
azithromycin
erythromycin is ineffective against H flu, causes GI distress
moa of macrolides
inhib 50S
macrolide toxicities
prolonged QT (monitor when pts taking other drugs like Class Ia or III AARD)
macrolide drug interactions
inhibit CYP3A4, increased effects from many drugs like warfarin
not as much inhibiton from azithromycin
other effects of macrolides
anti inflammatory
moa of doxycycline
30S inhibitor
doxy toxicities (4)
prolonged QT (monitor w/ other drugs)
photosensitivity (UV converts drug to immunoreactive form)
tooth discoloration
teratogenic- accumulates in bone and interferes with developement
PK issues w/ doxy
chelates cations and becomes insoluble
avoid taking w/ Ca, Mg, Al, Fe, Zn
rx for outpatient w/ comorbidities or recent AB use
FQ (G+/G-/A)
or B-lactam (G+/G-) and macrolide
avoid same drug as previously used
major respiratory FQs
levofloxacin, moxifloxacin, gemifloxacin
cipro is not effective against strep pneumo so not used
FQ moa
DNA synthesis inhibiton- targets DNA gyrase
FQ toxicities
prolonged QT, nephrotoxicity (interstitial nephritis), tendon rupture
avoid in pregnancy if there is an alternative
FQ drug interactions
interact w/ NSAIDs- cause CNS problems like tremors, anxiety, insomnia, seizures
recommended first line B lactams to be given w/ macrolide)
penicillin (amoxicillin) or cephalosporins (ceftriaxone, cefpodoxime, cefuroxime)
B lactam toxicities (4)
Type I allergy (true allergy, IgE mediated): anaphylaxis, hypotension, bronchospasm, angioedema
Type II (IgG): slower, inflammation, urticaria, fever
Type IV: rare but could be fatal Stevens Johnson syndrome (toxic epidermal necrolysis)
nephrotoxicity (mostly penicilins, early cephalosporins)
worst B lactam for pregnancy
imipenem
rx for inpatient non ICU
FQ
or B lactam plus macrolide
recommended B lactam inpatient non ICU
cefotaxime or ceftriaxone (IV/IM)
or ampicillin (IV/oral)
rx for inpatient ICU
B lactam and azithromycin
or B lactam and FQ
both require B lactam
B lactam moa
disrupt peptidoglycan in cell wall
which 2 bugs must be covered in ICU?
strep pneumo and legionella
which B lactam does not produce hypersensitivity
aztreonam
ICU recommendations
Aztreonam + FQ has best evidence (avoids B lactam hypersensitivity)
Rx when worried about pseudomonas or MRSA
for pseudomonas:
B lactam + FQ
or
B lactam + aminoglycoside + FQ
for MRSA: Vancomycin or linezolid
recommended B lactams for pseudomonas
piperacillin +tazobactam
cefepime
imipenem/meropenem
carbapenem toxicities
seizures- inhibit GABA receptors in brain (increased firing due to less hyperpolarization)
anti pseudomonal FQ
levofloxacin
cipro is but not against strep pneumo so not used empirically
aminoglycoside moa
inhibit 30S, selective for G-
aminoglycoside toxicities
ototoxicity- damage hair cells, often permanent
nephrotoxicity (acute tubular injury to glomerulus, PCT, collecting duct)- usually reversible
aminoglycoside and pregnancy
category D- not recommended
vancomycin moa/ category
glycopeptide- disrupts cell wall
linezolid moa/ category
oxazolienones- inhib 50S
vancomycin toxicities
nephrotoxicity, ototoxicity
these are rare w/ vanc alone, should be avoided w/ other toxic drugs like aminoglycosides
Red man syndrome- mast cell histamine release
-can be avoided w/ diluted dose over an hour w/ antihistamines
linezolid toxicities
myelosuppression and thrombocytopenia
linezolid drug interaction
inhibit breakdown of serotonin- interact w/ SSRIs and can cause serotonin syndrome (fever, agitation, tremor, sweating)
Rx w/ MSSA and Non MDR pseudomonas
piperacillin/tazobactam
cefepime
levofloxacin
imipenem or meropenem
anti pseudomonal and anti staph (G+)
Rx w/ MRSA and non MDR pseudomonas
MRSA- Vanc or linezolid
antipseudomonal- piper/tazobactam cefepime or ceftazidime levofloxacin imipenem or meropenem aztreonam
Rx for MSSA and MDR pseudomonas
B lactam anti pseudomonal (piper/tazo, cefipime or ceftazidime, imipenem or meropenem, aztreonam)
and non B lactam anti pseudomonal (levo, amikacin or gentamicin or tobramicin)
rx for MRSA and MDR pseudomonas
B lactam anti pseudomonal and non B lactam anti pseudomonal (same list + maybe colistin) and MRSA coverage w/ vanc and linezolin
colistin moa
cell membrane inhibitor by binding to LPS
colistin toxicities (3)
nephrotoxicity- mostly seen at high doses and not as bad as AGs
muscle weakness- interference w/ NMJ signaling
peripheral nerve damage, paresthesia
clindamycin moa
50S inhib
targets for clinda
G+ and G- anaerobes, esp for the aspiration pneumonias: bacteroides, prevotella, fusobacterium, peptostreptococcus
clinda toxicities
pseudomembranous colitis
C diff superinfection
