what is the mechanism of chloramphenicol?
inhibits 50S peptidyltransferase
describe the spectrum of chloramphenicol
broad spectrummostly bacteriostatic to all bacteria, except h. influenzae (bacteriocidal)
what is the clinical use of chloramphenicol?
restricted to life-threatening infections of h. influenzae, bacteriodes, rickettsia, and meningitis (serious infections where penicilin can’t be used due to allergy)
the utility of chloramphenicol is limited due to its severe ___
toxicity
does chloramphenicol cross the BBB?
yes
what are the adverse effects of chloramphenicol?
- hemolytic anemia, aplastic anemia (fatal), anemia, teratogenic, gray baby syndrome in premature infants
what are the serious drug interactions of chloramphenicol?
inhibits CYP450s to slow metabolism of warfarin, phenytoin (toxicity risk)
the mechanism of clindamycin is the same as ___
macrolidesit blocks peptide bond formation at the 50S subunit of bacterial ribosome (inhibits translocation step of protein synthesis)
___ is antagonistic if co-administered with macrolides
clindamycin
what is the spectrum of clindamycin?
- active against infections caused by non-enterococcal, gram + cocci
- no gram - activity
- bacteriostatic
urine levels of clindamycin are ___
non-therapeutic, so it is not good for UTIs
clindamycin can accumulate in patients with ___ or ___ failure
renal or liver
what are the adverse effects of clindamycin?
- pseudomembranous colitis - treated with oral vancomycin or metronidazole
- hematological disorders
- fever
- diarrhea
- cellulitis
what are the clinical uses for clindamycin?
- bone and joint infections
- anaerobes above the diaphragm
- gram + microbes
for patients with ___, clindamycin can be prescribed orally for months as an outpatient therapy
anaerobic aspiration pneumonia
what is the mechanism of linezolid?
binds to 50S subunit of bacterial ribosomes and blocks protein synthesis
what is the spectrum of linezolid?
- bactericidal (streptococci)
* bacteriostatic (enterococci and staphylococci)
what antibiotic has the following clinical uses?treatment of vancomycin-resistant E. faeciumnosocomial pneumonia (both meth-susceptible and MRSA)community acquired pneumoniacomplicated skin infections caused by strep, staph, and MRSA
linezolid
what are the adverse effects of linezolid?
- generally well-tolerated with rare side effects
- hematologic (2.4% of patients)
- chronic treatment has resulted in reversible neurotoxicity
patients receiving adrenergic or serotinergic agents while taking linezolid may develop ___
serotonin syndrome
quinuprostin/dalfopristin is in what ratio?
30:70
the synergistic effect of quinuprostin/dalfopristin causes ___to enhance quinuprostin binding
conformation change
what is the spectrum of quinuprostin/dalfopristin?
bacteriostatic
how should quinuprostin/dalfopristin be administered?
slow IV infusion onlyno dose adjustment needed in renal insufficiency
