antibioticsbooks

Monobactams
Agent: aztreonam
Aztreonam is the only monobactam currently available.
Structurally, aztreonam contains only the
four-membered ring of the basic beta-lactam structure,
hence the name monobactam. Aztreonam’s
quirk is that it seems to be safe to administer to
patients with allergies to other beta-lactams, except
patients who have a specific allergy to ceftazidime.
This cross-reactivity seems to be a result of the fact
that ceftazidime and aztreonam share an identical
side chain. Ceftazidime and aztreonam also share
virtually the same spectrum of activity. It is reasonably
safe to remember the utility of aztreonam
by thinking of it as ceftazidime without allergic
cross-reactivity with other beta-lactams.
Mechanism of Action
Like the other beta-lactams, monobactams inhibit
cross-linking of peptidoglycan in the cell wall, leading
to autolysis and cell death.
Spectrum
Good: Pseudomonas, most GNRs
Moderate: Acinetobacter
Poor: Gram-positive organisms, anaerobes
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