antibioticsbooks

Antipseudomonal Penicillins
Agents: piperacillin, mezlocillin, carbenicillin,
ticarcillin
None of the penicillins we have discussed thus far
offer appreciable activity against Pseudomonas
aeruginosa, a common nosocomial pathogen that
is often resistant to multiple antibiotics. Enter
the antipseudomonal penicillins. These agents are
active against Pseudomonas aeruginosa and other
more drug-resistant GNRs. However, they are just
as susceptible to beta-lactamases as penicillin and
ampicillin, so they are not antistaphylococcal. Also,
strains of GNRs that produce beta-lactamases are
resistant to them. They do have activity against
streptococci and enterococci.
Mechanism of Action
All beta-lactams inhibit cross-linking of peptidoglycan
in the cell wall, leading to autolysis and cell
death.
Spectrum
Good: Pseudomonas aeruginosa, streptococci,
enterococci
Moderate: enteric GNRs, Haemophilus
Poor: staphylococci, anaerobes
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