Editing Cefalexin (section)

===Pharmacokinetics===
Cefalexin is rapidly and almost completely absorbed from the [[gastrointestinal tract]] with [[oral administration]].<ref name="Keflex-Label" /> Absorption is slightly reduced when it is taken with food and the medication can be taken without regard for meals.<ref name="Keflex-Label" /> Peak levels of cefalexin occur about 1&nbsp;hour after administration.<ref name="Keflex-Label" /> Maximal levels of cefalexin increase approximately linearly over a dose range of 250 to 1,000&nbsp;mg.<ref name="Keflex-Label" />

Like most other cephalosporins, cefalexin is not [[metabolism|metabolized]] or otherwise inactivated in the body.<ref name="GraysonCosgrove2017">{{cite book| vauthors = Rafiei N | chapter = Cephalexin| veditors = Grayson M |title=Kucers' The Use of Antibiotics: A Clinical Review of Antibacterial, Antifungal, Antiparasitic, and Antiviral Drugs | edition = Seventh | chapter-url=https://books.google.com/books?id=3xE4DwAAQBAJ&pg=PA364|date=2 October 2017|publisher=CRC Press|isbn=978-1-4987-4796-7|pages=364–|access-date=13 July 2018|archive-date=28 August 2021|archive-url=https://web.archive.org/web/20210828023755/https://books.google.com/books?id=3xE4DwAAQBAJ&pg=PA364|url-status=live}}</ref><ref name="Skidmore-Roth2015">{{cite book | vauthors = Skidmore-Roth L |title=Mosby's Drug Guide for Nursing Students, with 2016 Update|url=https://books.google.com/books?id=g_BwCgAAQBAJ&pg=PA181|date=16 July 2015|publisher=Elsevier Health Sciences|isbn=978-0-323-17297-4|pages=181–|access-date=13 July 2018|archive-date=28 August 2021|archive-url=https://web.archive.org/web/20210828023811/https://books.google.com/books?id=g_BwCgAAQBAJ&pg=PA181|url-status=live}}</ref>

The [[elimination half-life]] of cefalexin is approximately 30 to 60&nbsp;minutes in people with normal renal function.<ref name="Skidmore-Roth2015" /><ref name="Keflex-Label" /> Therapeutic levels of cefalexin with oral administration are maintained for 6 to 8&nbsp;hours.<ref name="Keflex-Label">{{Cite web|url=https://www.medicines.org.uk/emc/product/9143/smpc|title=Cefalexin 500mg Tablets - Summary of Product Characteristics (SMPC) - (Emc)|access-date=5 March 2021|archive-date=19 April 2021|archive-url=https://web.archive.org/web/20210419094953/https://www.medicines.org.uk/emc/product/9143/smpc|url-status=live}}</ref> More than 90% of cefalexin is excreted unchanged in the urine within 8&nbsp;hours.<ref name="Keflex-Label" />