Monobactams Flashcards
Monobactams are produced by
chromobacterium violaceum
Monobactam structure
mono-cyclic beta-lactams; aminothiazole group=gram - spectrum; sulfonic acid= beta lactam activation; carboxy group= enhanced pseudomonas activity
Monobactam MOA:
consistent with beta lactam family, aztreonam inhibits PBP which alters cell morphology and viability
Aztreonam has a high affinity for
PBP-3
Aztreonam is bactericidal/bacteriostatic
bactericidal
Monobactam includes which drug
aztreonam
Aztreonam oral absorption
poor
Aztreonam 1/2 life
short
Aztreonam elimination
66% renal and 12% fecal
Aztreonam administration
IV, IM, inhaled
Monobactams are ___-dependent antimicrobials
time
Desired target for %T>MIC of dosing interval for Aztreonam
50
4 hour dialysis can remove about ___ of Aztreonam
38%
Aztreonam spectrum coverage
NO GRAM +
dark red: h. influenzae, m. catarrhalis, e.coli, klebsiella, p.mirabilis, Morganella, citrobacter, serratia
light red: enterobacter, p. aeruginosa
Misc: activity against NDM metal-beta-lactamases and unstable against ESBL and AmpC
Aztreonam has activity against
NDM metallo-beta-lactamases
Aztreonam resistance mechanisms
beta lactamases: susceptible by hydrolysis to ESBL, KPC, AmpC beta lactamases
outer membrane proteins (reduced entry)
efflux pumps
Aztreonam penetration into tissues
skin synovial fluid bone urine concentration=100 times higher than serum concentrations CSF is poor without inflammation lung eye is poor
Aztreonam should/should not be renal adjusted
should!
Aztreonam adverse effects
thrombophlebitis GI, c. diff rare skin hematologic CNS hepatic
Aztreonam indications
penicillin allergic patients
metallo-beta-lactamase producing enterobacteriaceae
Why can Aztreonam be given to patients with PCN allergy?
structurally dissimilar to other beta lactams
Aztreonam can have cross reactivity with
ceftazidime allergy bc of similar side chain
Aztreonam can be used only for gram
negatives
Aztreonam is typically reserved for patients with
severe beta lactam allergy
