Cefalexin

Cefalexin
Clinical data
Pronunciation/ˌsɛfəˈlɛksɪn/
Trade namesKeflex, others
Other namescephalexin, cephalexin (BAN UK), cephalexin (USAN US)
AHFS/Drugs.comMonograph
MedlinePlusa682733
License data
Pregnancy
category
Routes of
administration		By mouth
Drug classFirst-generation cephalosporin
ATC code
Legal status
Legal status
Pharmacokinetic data
BioavailabilityWell absorbed
Protein binding15%
Metabolism80% excreted unchanged in urine within 6 hours of administration
Elimination half-life0.6–1.2 hours[3]
ExcretionKidney
Identifiers
  • (7R)-3-methyl-7-(α-D-phenylglycylamino)-3-cephem-4-carboxylic acid monohydrate
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.036.142 Edit this at Wikidata
Chemical and physical data
FormulaC16H17N3O4S
Molar mass347.39 g·mol−1
3D model (JSmol)
Melting point326.8 °C (620.2 °F)
  • O=C2N1/C(=C(\CS[C@@H]1[C@@H]2NC(=O)[C@@H](c3ccccc3)N)C)C(=O)O
  • InChI=1S/C16H17N3O4S/c1-8-7-24-15-11(14(21)19(15)12(8)16(22)23)18-13(20)10(17)9-5-3-2-4-6-9/h2-6,10-11,15H,7,17H2,1H3,(H,18,20)(H,22,23)/t10-,11-,15-/m1/s1 checkY
  • Key:ZAIPMKNFIOOWCQ-UEKVPHQBSA-N checkY
  (verify)

Cefalexin, also spelled cephalexin, is an antibiotic that can treat a number of bacterial infections.[4] It kills gram-positive and some gram-negative bacteria by disrupting the growth of the bacterial cell wall.[4] Cefalexin is a β-lactam antibiotic within the class of first-generation cephalosporins.[4] It works similarly to other agents within this class, including intravenous cefazolin, but can be taken by mouth.[5]

Cefalexin can treat certain bacterial infections, including those of the middle ear, bone and joint, skin, and urinary tract.[4] It may also be used for certain types of pneumonia and strep throat and to prevent bacterial endocarditis.[4] Cefalexin is not effective against infections caused by methicillin-resistant Staphylococcus aureus (MRSA), most Enterococcus, or Pseudomonas.[4] Like other antibiotics, cefalexin cannot treat viral infections, such as the flu, common cold or acute bronchitis.[4] Cefalexin can be used in those who have mild or moderate allergies to penicillin.[4] However, it is not recommended in those with severe penicillin allergies.[4]

Common side effects include stomach upset and diarrhea.[4] Allergic reactions or infections with Clostridioides difficile, a cause of diarrhea, are also possible.[4] Use during pregnancy or breastfeeding does not appear to be harmful to the fetus.[4][6][7] It can be used in children and those over 65 years of age.[4] Those with kidney problems may require a decrease in dose.[4]

Cefalexin was developed in 1967.[8][9][10] It was first marketed in 1969 under the brand name Keflex.[11][12] It is available as a generic medication.[4][13] It is on the World Health Organization's List of Essential Medicines.[14] In 2022, it was the 101st most commonly prescribed medication in the United States, with more than 6 million prescriptions.[15][16] In Canada, it was the fifth most common antibiotic used in 2013.[17] In Australia, it was one of the top 10 most prescribed medications between 2017 and 2023.[18]

  1. ^ "Cephalexin Use During Pregnancy". Drugs.com. 28 December 2018. Archived from the original on 7 February 2020. Retrieved 7 February 2020.
  2. ^ Cite error: The named reference Lexylan PI was invoked but never defined (see the help page).
  3. ^ 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
  4. ^ a b c d e f g h i j k l m n o "Cephalexin". The American Society of Health-System Pharmacists. Archived from the original on 1 May 2014. Retrieved 21 April 2014.
  5. ^ Brunton LL (2011). "Chapter 53: Penicillins, Cephalosporins, and Other β-Lactam Antibiotics". Goodman & Gilman's pharmacological basis of therapeutics (12th ed.). New York: McGraw-Hill. ISBN 978-0071624428.
  6. ^ "Prescribing medicines in pregnancy database". Australian Government. 3 March 2014. Archived from the original on 8 April 2014. Retrieved 22 April 2014.
  7. ^ Jones W (2013). Breastfeeding and Medication. Routledge. p. 227. ISBN 9781136178153. Archived from the original on 8 September 2017.
  8. ^ Hey E, ed. (2007). Neonatal formulary 5 drug use in pregnancy and the first year of life (5th ed.). Blackwell. p. 67. ISBN 9780470750353. Archived from the original on 8 September 2017.>
  9. ^ US patent 3275626, Morin RB, Jackson BG, "Penicillin conversion via sulfoxide", published 1966-09-27, issued 1966-09-27, assigned to Eli Lilly and Co  "Espacenet - Bibliographic data". Archived from the original on 25 September 2022. Retrieved 3 March 2020.
  10. ^ US patent 3507861, Morin RB, Jackson BG, "Certain 3-methyl-cephalosporin compounds", published 1970-04-21, issued 1970-04-21, assigned to Eli Lilly and Co  "Espacenet - Bibliographic data". Archived from the original on 25 September 2022. Retrieved 3 March 2020.
  11. ^ McPherson EM (2007). "Cefalexin". Pharmaceutical Manufacturing Encyclopedia (3rd ed.). Burlington: Elsevier. p. 915. ISBN 9780815518563. Archived from the original on 8 September 2017.
  12. ^ Ravina E (2011). The evolution of drug discovery : from traditional medicines to modern drugs (1. Aufl. ed.). Weinheim: Wiley-VCH. p. 267. ISBN 9783527326693. Archived from the original on 8 September 2017.
  13. ^ Hanlon G, Hodges N (2012). Essential Microbiology for Pharmacy and Pharmaceutical Science. Hoboken: Wiley. p. 140. ISBN 9781118432433. Archived from the original on 8 September 2017.
  14. ^ World Health Organization (2023). The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023). Geneva: World Health Organization. hdl:10665/371090. WHO/MHP/HPS/EML/2023.02.
  15. ^ "The Top 300 of 2022". ClinCalc. Archived from the original on 30 August 2024. Retrieved 30 August 2024.
  16. ^ "Cephalexin Drug Usage Statistics, United States, 2013 - 2022". ClinCalc. Retrieved 30 August 2024.
  17. ^ "Human Antimicrobial Drug Use Report 2012/2013" (PDF). Public Health Agency of Canada (PHAC). November 2014. Archived (PDF) from the original on 21 March 2015. Retrieved 24 February 2015.
  18. ^ "Medicines in the health system". Australian Institute of Health and Welfare. 2 July 2024. Retrieved 30 September 2024.