Lecture 2 Flashcards
factors affecting empirical therapy
type of suspected infn, infn location, seriousness of infn, previous antimicrobial therapy, comorbidities
gram positive
blue cocci
gram negative
pink bacilli
common gram + microorg
staph, strep, enterococcus
Staph aureus
coagulase +, methicillin sensitive (MSSA) or resistant (MRSA) so PCN/cephalosporin will not be effective
Staph epidermidis
opportunistic pathogen, coagulase -
Staph saprophyticus
minor pathogen
Strep Pyrogenes
pyogenic, strongly B-hemolytic, causes pharyngitis, resp and skin infn
Strep Pneumoniae
causes pneumonia, sepsis, otitis media and meningitis, gram (+) cocci in pairs “diplococci”, causes a-hemolysis
E. faecalis
80-90% of clinical isolated, major enterococcal organism in GI tract
E. Faecium
5-10% of clinical isolates, increasingly Vanco-resistant
gram - microorganism
Citrobacter sp, Pseudomonas aeruginosa, Acinetobacter sp. - all prone to developing MDR
Pen G Aqueous
only administered IV/IM, acid labile-degraded orally
Pen G Benzathine (Bicillin L-A)
long acting - one time tx of early syphilis
lasts for 15-30 days in body
Pen G Wycillin
Lasts for hrs in body
Pen G Benzathine and Pen G Procaine (Bicillin C-R)
used to tx certain Strep infn, easily confused with Pen G Benzathine
lasts 24 hrs
Pen V
phenoxymethyl penicillin, acid stable
only for oral use in Na or K salts
Nafcillin
used to tx serious MSSA bloodstream infn
hepatic ally metal so no adjustment for renal impairment
Amoxacillin
-OH at para position improves oral abs
oral equivalent of ampicillin
Carbenicillin
1st PCN with activity against P. aeruginosa
Ticarcillin
2-4 x more activity against P. aeruginosa
rarely used alone due to B-lactamase hydrolysis
usually given IV with clavulante
cephalosporins
most are active against Staph/Strep
MRSA are resistant to all cephalosporins
cephamycins
2nd gen cephalosporins, sig activity over anaerobes
useful in and/GI sx prophylaxis
3rd gen cephalosporins
PO mainly for kids
ceftazidime
may accelerate acquired resistance
ceftriaxone
used with azithromycin for CAP
4th gen cephalosporins
widest spectrum of all cephalosporins
useful against many MDR gram - bacilli
70-80% gram - bacilli resistant to ceftazidime are sensitive to 4th gen’s
carbapenems
broadest activity of B-lactam class due to improved B-lactamase stability excellent gram +, - and anaerobic coverage
impenem (primaxin)
add Cilastin - prevents renal metab
Dorpenem (doribax)
newest carbapenem, little coverage against P aeruginosa
Metronidazole (Flagyl)
good oral abs, same PO/IV dose
hepatic ally metab (no renal adjustments)
erythromycin
sig GI upset
Clarithromycin
less GI upset than erythromycin
Azithromycin
least GI upset, covers more atypical org’s
Telithromycin (Ketek)
ketolide/macrolide, inc risk of hypoglycemia in top 2 diabetes
Vanco
glycopeptides, initially relegated to PCN allergic pt’s
inc use in 80’s
TMP and SMX
block consecutive steps in bacterial folate syn
used extensively for UTIs
PO Dose UTIs: 1 DS tab q12h
quinolones
fluorine derivatives greatly improved potency
cidal
inhibition of DNA -gyrase and topoisomerase IV
most active against gram - org
pseudomonas resistance emerges if used as mono therapy
Ciprofloxacin
cystitis: 250 mg q12h x 3 d; IV 200 mg
LRTI: 500-750 mg PO q12h x 7-14d; IV 400 mg
Moxifloxacin (Avelox)
non-renally eliminated
recently FDA approved for UTIs
hepatic ally metab
IV to PO
afebrile > 24h WBC normal or normalizing (NML 10000-12000) tolerating oral diet no nausea/vomiting no contraindications for PO
