ID lecture

the sanford guide to antimicrobial therapy- use to guide choice of antimicrobial

antibiogram - for hospital gives readout of major susceptibility for the hospital you're in

antibiotics ppx for surgery need to know three things

1. drug of choice

2. pre-operative timing- give abx within 60 minutes (2hrs w/vancomycin*) to right before skin incision - all needs to be in if you're going to use tourniquet

3. where indication

*b/c longer half life ~6hours and need to infuse slow (red man syndrome)

abx administration delegated to anesthesiologist

post op abx - no indication for this but standards allow for up until 24hours, limit to one dose post op.

surgery goes >2 half lives the drug should be readministered

staph epi most common hosp acquired infection since 2000

cephalosporins – beta-lactam antibiotics that cover a broad range of organisms that are resistant to beta lactamases

drug resistance to vancomycin and cephalosporins increasing

now, we have fifth generation -

ceftobiprole (Zeftera) - currently approved in Canada, currently under FDA review

volume of distribution equal to ECF, renally cleared half life 3-4hrs

current dosing is 500mg IV q8h (q12 in gram+, foot infections)

shown to be as effective as vanc + ceftazidime in copmlicated skin infx (cSSSIs, Clin Infect Dis. 2008;46(5):647-55)

adverse effects

dysgeusia, nausea, headache

binds penicillin binding protein 2a (this is the one that makes staph resistant to beta-lactam aka MRSA)

binds penicillin binding protein 2x - this is the one that makes s. pneumoniae resistant to penicillin

has activity against enterobacteriaceae and enterococci

ceftaroline fosamil -still under review by FDA

dose is 600mg iv q12hr, converted from prodrug in serum, renally excreted half life ~2.5hrs

not strongly plasma protein bound

binds penicillin binding protein 2a (this is the one that makes staph resistant to beta-lactam aka MRSA)

binds penicillin binding protein 2x - this is the one that makes s. pneumoniae resistant to penicillin

activity against gram + (mrsa, visa/vrsa, and macrolide resistant s. pyo)

not good for psuedomonas or ESBL (exteded spectrum beta lactamase producers)

covers gram negative (h. influenza, moraxella, enterobacteriaceae) but resistance has a tendency to form in enterobacteriaceae

synergistic w/tobramycin vs. MRSA, hVISA

Safety- similar to other cephalosporins, side effects -mild transaminitis, urine discolor/odor, calcium oxalate crystals,

on the other side-

NDM-1 - first discovered in 2008

new dehli metallo beta lactamase a transmissable genetic element (plasmid) described in dec2009 in patient w/klebsiella (but can be found in all enterobacteriaceae) pneumonia/uti in india found to be resistant to all tested anti-microbials except colistin-> now reported in asia, europe, north America