Ceftazidime (Fortaz, Tazidime) is a β-lactamase–resistantthird-generation cephalosporin that is noted for its antipseudomonalactivity. It is active against some strains of P.aeruginosa that are resistant to cefoperazone and ceftriaxone.Ceftazidime is also highly effective against β-lactamase–producing strains of the Enterobacteriaceae family. Itis generally less active than cefotaxime against Gram-positivebacteria and B. fragilis. The structure of ceftazidime contains two noteworthyfeatures: (a) a 2-methylpropionicoxaminoacyl group thatconfers -lactamase resistance and, possibly, increasedpermeability through the porin channels of the cell envelopeand (b) a pyridinium group at the 3-position that conferszwitterionic properties on the molecule. Ceftazidime is administered parenterally 2 or 3 timesdaily, depending on the severity of the infection. Its serumhalf-life is about 1.8 hours. It has been used effectively forthe treatment of meningitis caused by H. influenzae andN. meningitidis.
