Beta-lactam antibiotics

Penicillin

Aztreonam

monocyclic beta-lactam

inhibits cell wall synthesis

binds to penicillin-binding protein 3

synergistic with aminoglycosides

used as "aminoglycoside pretender" - covers serious gram negative bugs (E. coli, Klebsiella, Pseudomonas, Serratia, etc.)

Penicillin-allergic patients and those with renal insufficiency (non-toxic)

no cross-sensitivity with penicillins

Carbapenems

Imipenem/cilastatin

Meropenem

Ertapenem

Doripenem

N.B. Cilastatin is added to inhibit dehydropeptidase in kidney, which is responsible for degrading imipenem

extended broad spectrum, but does NOT cover MRSA

Meropenem

reduce risk of seizures

Not inactivated in the renal tubules