Ceftazidime (INN) is a third-generation cephalosporin antibiotic. Like other third-generation cephalosporins, it has broad spectrum activity against Gram-positive and Gram-negative bacteria. Unlike most third-generation agents, it is active against Pseudomonas aeruginosa, however it has weaker activity against Gram-positive microorganisms and is not used for such infections. Ceftazidime pentahydrate is marketed under various trade names including Fortum (GSK).

Clinical use

Ceftazidime is usually reserved for the treatment of infections caused by Pseudomonas aeruginosa. It is also used in the empirical therapy of febrile neutropenia, in combination with other antibiotics. The usual dose is 1–2 g IV/IM every 8–12 hours(2 - 3times), though this can vary by the indication, infection severity, and/or renal function of the recipient. It is also first line treatment for the rare tropical infection, melioidosis.

Chemistry

In addition to the syn-configuration of the imino side chain, compared to other third-generation cephalosporins, the more complex moiety (containing two methyl and a carboxylic acid group) confers extra stability to β-lactamase enzymes produced by many Gram-negative bacteria. The extra stability to β-lactamases increases the activity of ceftazidime against otherwise resistant Gram-negative organisms including Pseudomonas aeruginosa. The charged pyridinum moiety increases water-solubility.

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