Following an appendectomy, a 28-year-old man is placed on ceftizoxime sodium (Cefizox). This antibiotic is unlikely to be effective against which of the following?

Cefizox is not effective against many strains of Pseudomonas. If the drug is used in pseudomonas infection a higher dosage may be indicated, and the antibiotic should be changed if a quick response does not occur. Complications include cross reactions in patients who are allergic to penicillin. It does not seem to have nephrotoxic side effects.