Cefalexin

From Wikipedia, the free encyclopedia - View original article

Cefalexin
Systematic (IUPAC) name
(6R,7R)-7-{[(2R)-2-amino-2-phenylacetyl]amino}- 3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene- 2-carboxylic acid
Clinical data
Trade namesKeflex
AHFS/Drugs.commonograph
MedlinePlusa682733
Licence dataUS FDA:link
Pregnancy cat.A (AU) B (US)
Legal statusPrescription Only (S4) (AU) POM (UK) -only (US)
RoutesOral
Pharmacokinetic data
BioavailabilityWell absorbed
Protein binding15%
Metabolism80% excreted unchanged in urine within 6 hours of administration
Half-lifeFor an adult with normal renal function, the serum half-life is 0.5-1.2 hours[1]
ExcretionRenal
Identifiers
CAS number15686-71-2 YesY
ATC codeJ01DB01 QJ51DB01
PubChemCID 2666
DrugBankDB00567
ChemSpider25541 YesY
UNII5SFF1W6677 YesY
KEGGD00263 YesY
ChEBICHEBI:3534 YesY
ChEMBLCHEMBL1727 YesY
Chemical data
FormulaC16H17N3O4S 
Mol. mass347.39 g/mol
 YesY (what is this?)  (verify)
 
Jump to: navigation, search
Cefalexin
Systematic (IUPAC) name
(6R,7R)-7-{[(2R)-2-amino-2-phenylacetyl]amino}- 3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene- 2-carboxylic acid
Clinical data
Trade namesKeflex
AHFS/Drugs.commonograph
MedlinePlusa682733
Licence dataUS FDA:link
Pregnancy cat.A (AU) B (US)
Legal statusPrescription Only (S4) (AU) POM (UK) -only (US)
RoutesOral
Pharmacokinetic data
BioavailabilityWell absorbed
Protein binding15%
Metabolism80% excreted unchanged in urine within 6 hours of administration
Half-lifeFor an adult with normal renal function, the serum half-life is 0.5-1.2 hours[1]
ExcretionRenal
Identifiers
CAS number15686-71-2 YesY
ATC codeJ01DB01 QJ51DB01
PubChemCID 2666
DrugBankDB00567
ChemSpider25541 YesY
UNII5SFF1W6677 YesY
KEGGD00263 YesY
ChEBICHEBI:3534 YesY
ChEMBLCHEMBL1727 YesY
Chemical data
FormulaC16H17N3O4S 
Mol. mass347.39 g/mol
 YesY (what is this?)  (verify)

Cefalexin (INN) or more commonly cephalexin /ˌsɛfəˈlɛksɨn/ is a first-generation cephalosporin antibiotic introduced in 1967 by Eli Lilly and Company.[2][3] It is an orally administered agent with a similar antimicrobial spectrum to the intravenous agents cefalotin and cefazolin. It was first marketed as Keflex (Lilly), and is marketed under several other trade names.[2]

As of 2008, cefalexin was the most popular cephalosporin antibiotic in the United States, with more than 25 million prescriptions of its generic versions alone, for US$255 million in sales (though less popular than two other antibiotics, amoxicillin and azithromycin, each with 50 million prescriptions per year).[4][5]

Medical uses[edit]

Cefalexin is used to treat a number of infections including: otitis media, streptococcal pharyngitis, bone and joint infections, pneumonia, cellulitis, and urinary tract infections.[6] It may be used to prevent bacterial endocarditis.[6]

Infections[edit]

In addition to being a rational first-line treatment for cellulitis, it is a useful alternative to penicillins in patients with penicillin hypersensitivity. In patients with mild or questionable history of penicillin allergy, cephalasporins are now thought to be relatively safe.[7] Caution should always be taken when prescribing cephalosporins to those with strong history of true penicillin hypersensitivity, however, because cefalexin and other first-generation cephalosporins are known to have a modest cross-allergy in patients with penicillin hypersensitivity.[citation needed]

Cefalexin may not be effective against bacteria that incorporate a gene for beta-lactamase on their R-plasmid as the beta-lactam ring is present in the chemical structure of cephalosporin derivatives.[citation needed]

Formulations[edit]

Cefalexin is marketed by generic pharmaceutical manufacturers under a wide range of brand names, including: Apo-Cephalex, Biocef, Cefanox, Ceforal, Cephabos, Cephalexin, Cephorum, Ceporex, Cilex, Ialex, Ibilex, Kefexin, Keflet, Keflex, Rekosporin, Keforal, Keftab, Keftal, Lopilexin, Larixin, Novo-Lexin, Ospexin, Tenkorex, Zephalexin, Panixine Disperdose, Rancef, Sialexin, Sporidex and Ulexin.

A version of Keflex 750 mg capsules is marketed for twice-daily dosage, to improve compliance. However, it is not a sustained release formulation, and since it is more expensive than the older strengths, some physicians prescribe three 250 mg capsules to be taken twice daily, as a less expensive alternative.[citation needed]

In Finland, cefalexin is marketed under several names. Orion markets Kefexin.[8][9]

Adverse effects[edit]

Common adverse effects include gastrointestinal upset such as diarrhea, nausea, vomiting, indigestion, and abdominal pain.[6] Others may include dizziness, agitation, headache, joint pain, and tiredness. Symptoms of an allergic reaction include rash, itching, swelling, trouble breathing, or red, blistered, swollen or peeling skin. Overall, allergies occur in less than 0.1% of patients; they are seen in about 1% to 10% of patients with penicillin allergy.[10]

References[edit]

  1. ^ McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug Information 95. Bethesda, MD: American Society of Hospital Pharmacists, Inc., 1995 (Plus Supplements 1995)., p. 166
  2. ^ a b Sweetman, Sean C., ed. (2009). "Antibacterials". Martindale: The complete drug reference (36th ed.). London: Pharmaceutical Press. pp. 218–9. ISBN 978-0-85369-840-1. 
  3. ^ Sneader, Walter (2005). "Cephalosporin analogues". Drug discovery: a history. New York: Wiley. p. 324. ISBN 0-471-89980-1. Retrieved 2009-06-26. 
  4. ^ "2008 Top 200 generic drugs by total prescriptions"  PDF (332.8 KB). Drug Topics (May 26, 2009). Retrieved on July 24, 2009.
  5. ^ "2008 Top 200 generic drugs by retail dollars"  PDF (399.4 KB). Drug Topics (May 26, 2009). Retrieved on July 24, 2009.
  6. ^ a b c "Cephalexin". The American Society of Health-System Pharmacists. Retrieved 3 April 2011. 
  7. ^ Pichichero ME (March 2007). "Use of selected cephalosporins in penicillin-allergic patients: a paradigm shift". Diagnostic Microbiology and Infectious Disease 57 (3 Suppl): 13S–18S. doi:10.1016/j.diagmicrobio.2006.12.004. PMID 17349459. 
  8. ^ http://spc.nam.fi/indox/nam/html/nam/humpil/2/244412.pdf.
  9. ^ http://spc.nam.fi/indox/nam/html/nam/humspc/2/244362.shtml.
  10. ^ Haberfeld, H, ed. (2009). Austria-Codex (in German) (2009/2010 ed.). Vienna: Österreichischer Apothekerverlag. ISBN 3-85200-196-X. 

External links[edit]