Antimicrobials & SSTIs Flashcards
Therapeutic balance of ID
Maximize ____ and minimize ___
Maximize bacterial killing, safety, and efficacy
Minimize toxicity & resistance
ecological adverse effects of antibiotic therapy, specifically selection of drug-resistant organisms and the unwanted development of colonization or infection with MDR organisms
collateral damage
collateral damage risks associated with cephalosporin
-subsequent infections with VRE
-extended spectrum B-lactamase producing K. pneumoniae
-B-lactam resistant Acinetobacter species
-C. diff
the lowest concentration of an antibiotic that completely inhibits the growth of a microorganism in vitro
MIC
the lowest concentration of the antibiotic which results in a 99.9% reduction in colony forming units in a given time
MBC
species that is
-gram + cocci
-clusters (catalase -)
-coagulase +
S. aureus
species that is
-gram + cocci
-clusters (catalase -)
-coagulase -
S. epidermidis
species that is
-gram + cocci
-pairs (catalase +)
-alpha
S. pneumoniae
species that is
-gram + cocci
-chains
-beta
Group A strep (S. pyogenes)
Group B strep (S. agalactiae)
Group C, G, F strep
species that is
-gram + cocci
-chains
-gamma
enterococcus species
E. faecalis
E. faecium
drugs for MSSA (S. aureus, 50%)
nafcillin, oxacillin, dicloxacillin
drugs for MRSA (S. aureus, 50%)
vancomycin, linezolid, daptomycin, Bactrim, clindamycin
drugs for MSSE (S. epidermidis, 20%)
nafcillin, oxacillin, dicloxacillin (same as MSSA)
drugs for MRSA (S. epidermidis, 80%)
vancomycin, linezolid, daptomycin, Bactrim, clindamycin (same as MRSA)
drugs for PCN (S) S. pneumoniae (90%)
penicillin G/V, nafcillin
drugs for PCN (R) S. pneumoniae (10%)
vancomycin, Bactrim
drugs for PCN (S) streptococcus
penicillin G/V, nafcillin (same as S. pneumoniae)
drugs for PCN (R) streptococcus
vancomycin, Bactrim (same as S. pneumoniae)
drug options for enterococcus species (E. faecalis, E. faecium)
- ampicillin +/- gentamicin
- vancomycin +/- gentamicin
- linezolid, daptomycin
drug for gram positive aerobe cocci
clindamycin
drug for gram positive aerobe bacilli
metronidazole
gram - cocci PEK species
Proteus mirabilus
Escherichia coli
Klebsiella pneumoniae
gram - cocci HEM species
Haemophilus influenzae
Enterobacteriaceae (salmonella, shigella)
Monexella catanthalis
gram - cocci SPACE species
Serratia marcesens
Pseudomonas aeruginosa
Acinetobacter baumannii
Citrobacter
Enterobacter
cephalosporins that cover PEK bacteria
cefazolin, cephalexin, cefadroxil
cephalosporins that cover PEKHEM bacteria
1) cefuroxime, cefaclor
2) cephamycins, cefoxitin, cefotetan cefmetazole
cephalosporins that cover PEKHEM S_ACE bacteria
1)Ceftriaxone, cefpodoxime proxetil
anti-pseudomonal: ceftazidime, cefoperazone
2) cefepime
3) ceftaroline
which cephalosporin is best for SPACE organisms
ceftazidime
which drugs are used for pseudomonas
combinations including:
-piperacillin/tazobactam
-carbapenems (meropenem, imipenem)
-ceftazidime
PKPD indices for antibiotic effect
Cmax:MIC
%T>MIC
AUC:MIC
which drugs follow:
-time dependent killing
-min/mod persistent effects
penicillins
cephalosporins
carbapenems
macrolides
oxazolidinones
what is the PKPD index that influences time dependent killing and min/mod persistent effects
%T/MIC
which drugs follow:
-concentration dependence
-prolonged persistent effects
aminoglycosides
quinolones
which PKPD indices influence concentration dependence and prolonged persistent effects
Cmax:MIC
AUC:MIC
which drugs follow:
-time dependent killing
-prolonged persistent effects
vancomycin
azithromycin
tetracycline
which PKPD index influences time dependent killing and prolonged persistent effects
AUC:MIC
how do pH changes alter PK
altered drug ionization
how do changes in organ blood flow alter PK
altered drug CL
how to fluid shifts alter PK
altered Vd
how do changes in albumin alter PK
changes in free drug
hydrophilic antimicrobials
aminoglycosides
beta lactams (carbapenems, cephalosporins, penicillins)
glycopeptides
lipopeptides
lipophilic antimicrobials
fluoroquinolones
glyclcycline
ketolides
lincosamides
macrolides
metronidazole
streptogramins
tetracyclines
how do hydrophilic drugs alter PK
tissue distribution limited to extracellular space
inc LD and inc/dec MD
how do lipophilic drugs alter PK
tissue distribution with intracellular accumulation
no change to LD or MD
how does infection in blood alter PK
inc Vd and CL
how does infection in lung alter PK
impaired permeability
how does infection in soft tissue alter PK
variable by composition
how does infection in bone alter PK
impaired permeability
how does infection in the CNS alter PK
impaired permeability
fluid shifts in sepsis do what to CL, Vd, and drug conc?
can lead to high or low Vd, impaired or augmented CL, and too high or too low drug conc
antibiotics that do not need renal dose adjustment
ceftriaxone
clindamycin
oxacillin
moxifloxacin
metronidazole
azithromycin
nafcillin
doxycycline
erythromycin
dalfopristin/quinupristin
tigecycline
linezolid
decisions for which drug to use should be made based off
S, R, or I…. NOT the number
greater outcomes were seen for fluoroquinolones with an AUC:MIC
> 125
target AUC24,ss:MIC for vancomycin
> 400 ng*h/L
types of purulent infections
cutenous abscess, furuncle, carbuncle
presentation of purulent infection
painful, fluctuant red nodules, topped with pustule, rim of erythematous swelling
common microbial cause of purulent infection
S. aureus
General treatment approach for purulent infections
must do I&D
antibiotics if there are systemic signs of infection, do not respond to I&D, etc (SIRS criteria, mod to sev)
IV drugs for purulent MRSA infections (empiric)
vancomycin, daptomycin, ceftaroline, dalbavancin/oritavancin
oral drugs for purulent MRSA infections (empiric)
Bactrim, doxycycline, linezolid
IV drugs for purulent MSSA infections (de-escalate)
ampicillin/sulbactam, nafcillin/oxacillin, cefazolin
oral drugs for purulent MSSA infections (de-escalate)
amox/clav, dicloxacillin, cephalexin, clindamycin
duration of therapy purulent infection
5-10 days following I&D
types of nonpurulent infection
cellulutis, erysipelas
presentation of nonpurulent infection
red, warm, swollen, painful
common microbial cause of nonpurulent infection
streptococcus species, some S. aureus
general treatment approach for nonpurulent infection
antibiotics
oral for mild
oral or IV for moderate
IV for severe
oral drugs for nonpurulent infection (strep)
penicillin VK, amoxicillin, amox/clav, cephalexin, clindamycin (allergy)
IV drugs for nonpurulent infection (strep)
penicillin G, cefazolin, ceftriaxone, clindamycin (allergy)
severe allergy- clindamycin, vancomycin, linezolid, daptomycin
treatment duration for nonpurulent infection
5 days if mild, 10-14 if mod-sev
deep infection involving the superficial fascia comprising all tissue between the skin and muscle
necrotizing fasciitis
microbial causes of necrotizing fasciitis
mono: S. pyogenes, S. aureus, Clostridium
poly: mixed aerobic/anaerobic
general treatment approach for necrotizing fasciitis
surgery
broad spectrum antibiotics started then de-escalated
drug for necrotizing fasciitis that covers MRSA
vancomycin +
drug for necrotizing fasciitis that covers gram -
pip-tazo, carbapenems, cefepime +, ciprofloxacin +
drug for necrotizing fasciitis that covers anaerobes
pip-tazo, carbapenems, metronidazole, clindamycin
microbial species common in infected animal bites
pasturella species
oral and IV drugs for bite wounds
IV- ampicillin/sulbactam
Oral- amox/clav
Alt- 2nd/3rd gen cephalosporins + metronidazole, levofloxacin + metronidazole
presentation for DFIs
redness, warmth, swelling, tenderness, pain, purulent drainage (from ulcer) (need 2 or more to be infected)
microbes that cause DFIs
gram + cocci: staphylococcus and streptococcus
gram - bacilli: pseudomonas
anaerobes: may be seen in mod-sev
mild oral therapy for DFI
MSSA/strep- cephalexin, amox/clav, clindamycin
MRSA- bactrim, doxycycline
mod-severe IV therapy for DFI
MSSA/strep/gram neg/anaerobes- amp/sulbact, cefoxitin, ceftriaxone + metro, cipro + clindamyc, moxifloxacin, ertapenem
MRSA- vancomycin, linezolid, daptomycin
pseudomonas- pip/tazo, cefepime
