Ceftazidime

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Ceftazidime
Ceftazidime.svg
Ceftazidime ball-and-stick.png
Systematic (IUPAC) name
(6R,7R,Z)-7-(2-(2-aminothiazol-4-yl)-
2-(2-carboxypropan-2-yloxyimino)acetamido)-8-oxo-
3-(pyridinium-1-ylmethyl)-5-thia-1-aza-bicyclo[4.2.0]
oct-2-ene-2-carboxylate
Clinical data
Trade names Fortaz, Tazicef
AHFS/Drugs.com monograph
MedlinePlus a686007
Pregnancy cat. B1 (AU) B (US)
Legal status Prescription Only (S4) (AU)
Routes Intravenous, intramuscular
Pharmacokinetic data
Bioavailability 91% (IM)
Metabolism negligible
Half-life 1.6–2 hours
Excretion 90–96% renal
Identifiers
CAS number 72558-82-8 YesY
ATC code J01DD02
PubChem CID 5481173
DrugBank DB00438
ChemSpider 4587145 YesY
UNII DZR1ENT301 YesY
ChEBI CHEBI:3508 YesY
ChEMBL CHEMBL201 N
Chemical data
Formula C22H22N6O7S2 
Mol. mass 546.58 g/mol
 N (what is this?)  (verify)

Ceftazidime (INN) /sɛfˈtæzɨdm/ is a third-generation cephalosporin antibiotic. As a class, the third generation cephalosporins mostly share the moderate activity of earlier generations against Gram-(+) bacteria such as streptococci, and share their lack of activity against more difficult Gram-(+) bacteria such as methacillin-resistant Staphylococcus aureus and Enterococci. The exhibit broader activity against Gram-(-) bacteria such as Escherichia coli, Klebsiella pneumoniae, and Haemophilus influenzae that are important causes of urinary tract infections, abdominal infections, pneumonia, and meningitis. As such, they are commonly used in first line therapy of serious and/or hospital acquired infections and as second line therapy for infections acquired in the community. This difference in part reflects greater expectations that hospital acquired infections will be resistant to older, narrower spectrum antibiotics.[1][2]

Third generation cephalosporins differ from earlier generations in the presence of a C=N-OCH3 group in their chemical structure. This group provides improved stability against certain beta lactamase enzymes produced by Gram-(-) bacteria. These enzymes rapidly destroy earlier generation cephalosporins by catalyzing the opening of the four member ring. With widespread use of third generation cephalosporins, some Gram-(-) bacteria have developed the ability to produce extended spectrum beta lactamases (ESBLs) that are able to hydrolyze third generation cephalosporin. Infections caused by ESBL producing Gram-(-) bacteria is of particular concern in hospitals and other healthcare facilities.[3]

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 Cefzim (Pharco B International), Fortum (GSK), and Fortaz.also marketed by eipico under trade name cefidime

Clinical use[edit]

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. It is usually given IV or IM every 8–12 hours (2 - 3 times a day), with dosage varying by the indication, infection severity, and/or renal function of the recipient.

Ceftazidime is first line treatment for the rare tropical infection, melioidosis.[4]

Chemistry[edit]

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 pyridinium moiety increases water-solubility.

References[edit]

  1. ^ hauser. antibiotic basics for clinicians. 
  2. ^ Peleg AY, Hooper DC (May 2010). "Hospital-acquired infections due to gram-negative bacteria". N. Engl. J. Med. 362 (19): 1804–13. doi:10.1056/NEJMra0904124. PMC 3107499. PMID 20463340. 
  3. ^ Sharma M, Pathak S, Srivastava P (October 2013). "Prevalence and antibiogram of Extended Spectrum β-Lactamase (ESBL) producing Gram negative bacilli and further molecular characterization of ESBL producing Escherichia coli and Klebsiella spp". J Clin Diagn Res 7 (10): 2173–7. doi:10.7860/JCDR/2013/6460.3462. PMC 3843424. PMID 24298468. 
  4. ^ White NJ (2003). "Melioidosis". Lancet 361 (9370): 1715–722. doi:10.1016/S0140-6736(03)13374-0. PMID 12767750.