Article: Cefalexin

Cefalexin
Systematic (IUPAC) name
8-(2-amino-2-phenyl-acetyl)amino -4-methyl-7-oxo-2-thia-6-azabicyclo [4.2.0]oct-4-ene-5-carboxylic acid
Identifiers
CAS number	15686-71-2
ATC code	J01DB01
PubChem	2666
DrugBank	APRD00250
Chemical data
Formula	C16H17N3O4S
Mol. weight	347.39 g/mol
Pharmacokinetic data
Bioavailability	Well absorbed
Metabolism	90% excreted unchanged
Half life	0.9 hours
Excretion	renal
Therapeutic considerations
Pregnancy cat.	A(AU)
Legal status	S4(AU) POM(UK)
Routes	oral

Cefalexin (INN) (IPA: [kɛfəˈlɛksən, sɛfə-]) or cephalexin (USAN) is a first-generation cephalosporin antibiotic. It is an orally-administered agent with a similar antimicrobial spectrum to the intravenous agents cefalotin and cefazolin. It is commonly marketed under the trade name Keflex (Lilly).

Clinical use

Main article: Cephalosporin

Indications

Cefalexin is used to treat urinary tract infections, respiratory tract infections (including sinusitis, otitis media, pharyngitis, tonsillitis and pneumonia), skin and soft tissue infections.

Although it is not generally considered first-line therapy for any indication, it is a useful alternative to penicillins in patients with penicillin hypersensitivity. There is, however, cross-reactivity in 10% of patients with hypersensitivity to penicillins and carbapenems.

Formulations

Cefalexin is commonly marketed as capsules (250 mg and 500 mg), tablets, and powder for oral suspension (125 mg/5 mL and 250 mg/5 mL).

It is marketed by generic pharmaceutical manufacturers under a wide range of brand names, including: Apo-Cephalex, Biocef, Cefanox, Ceporex, Cilex, Keflet, Keflex, Keforal, Keftab, Keftal, Lopilexin, and Panixine Disperdose.

See also

• Cephalosporin
• Cefazolin