Exam 2 - Study Guide Flashcards
how will interstitial nephritis present
abrupt increase in SCr
what penicillins should be used in caution in patients w/ CHF or renal failure and why
high sodium content
Aq. pen G
Nafcillin
Ticarcillin (worst one)
Piperacillin
what penicillins will most likely cause interstitial nephritis
methicillin
nafcillin
describe the cross-reactivity between cephalosporins and penicillins
cross reactivity highest with 1st gen cephalosporins
cefazolin worst one
what cephalosporins have the MTT side chain
cefamandole, cefotetan, cefmetazole, cefoperazone, moxalactam
what is the clinical significance of the MTT side chain
hypoprothrombinemia
disulfram reaction
hematologic reaction
describe carbapenem use in penicillin allergic patients
cross reactivity can occur
evaluate the severity
what is a direct toxic effect of carbapenems
central nervous system - seizures
what is a risk factor for seizures for patients on carbapenems
renal dysfunction
preexisting CNS disorders
high doses
imipenem has the highest risk
what is the purpose of cilastin
DHP inhibitor added to imipenem to prevent breakdown of drug in the kidney and nephrotoxicity
use of monobactams in penicillin allergic patients
low incidence of cross reactivity and CAN be used in penicillin allergies
what is the general mechanism of action for b-lactams
inhibit cell wall synthesis
what are the 3 mechanisms of resistance against beta lactams
-hydrolysis by BL enzymes
-alteration in penicillin binding protein
-decreased permeability of GN cell membranes
what kind of killers are B-lactams
time dependent bactericidal activity
T>MIC
what are the half-lives of beta lactams
<2 hours require frequent dosing
what are the Blactams that have longer half lives
ceftriaxone
cefotetan
cefixime
ertapenem
what is the half life of ceftriaxone
8 hours
what are the PK advantages of fluoroquinolones
PAE
good oral absorption
rapid, concentration dependent killer
what are the risk factors for cardiac toxicities for FQs
hypokalemia
amiodarone/sotalol
QTc prolongation
what are the DDIs for macrolides
CYP 3A4 and 2CP for clarithro and erythro
-theophylline
-carbamazepine
-valproate
-cyclosporine
-digoxin
-phenytoin
-warfarin
what macrolide does not inhibit cyp
azithromycin - still caution use with warfarin due to hypoprothrombinemia
