Last update Feb. 5, 2022

Cefalexin, Cefalexin Hydrochloride


Safe substance and/or breastfeeding is the best option.

First generation cephalosporin. Oral administration.

Like most cephalosporins for which data are available, it is excreted in human milk in a clinically non-significant amount (Ilett 2006, Matsuda 1984, Kafetzis 1981). The pediatric relative dose is well below 1%. (van Wattum 2021)

Few problems have been reported in infants whose mothers took it.

It can cause gastroenteritis by altering the intestinal flora of the infant. (Ilett 2006, Benyamini 2005, Ito 1993)

A case of allergic reaction to cephalexin through its own mother’s milk has been published on a previously sensitized infant after administration of another cephalosporin intravenously. (Chu 2019)

Cephalosporins are widely used in Pediatrics with very good tolerance, even from the neonatal period, so it is very unlikely that, in small amounts through their own mothers’milk, they can cause problems for the infant.

Cephalexin is an antibiotic indicated for mastitis. (Amir 2014, Jahanfar 2013, Spencer 2008)

Various medical societies and expert consensus consider the use of this medication safe during breastfeeding. (de Sá Del Fiol 2016, Butler 2014, Rowe 2013, Kong 2013, Amir 2011, Bar-Oz 2003, Fulton 1992)


Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Cefalexin, Cefalexin Hydrochloride is also known as Cephalexin.

Cefalexin, Cefalexin Hydrochloride in other languages or writings:


Cefalexin, Cefalexin Hydrochloride belongs to this group or family:


Main tradenames from several countries containing Cefalexin, Cefalexin Hydrochloride in its composition:


Variable Value Unit
Oral Bioavail. 95 %
Molecular weight 365 daltons
Protein Binding 10 - 15 %
VD 0.25 l/Kg
Tmax 1 hours
0.9 - 1.3 hours
M/P ratio 0.01 - 0.1 -
Theoretical Dose 0.08 mg/Kg/d
Relative Dose 0.45 %
Ped.Relat.Dose 0.08 - 0.2 %


  1. Chu YN, Lee MS, Yang SC, Tai HC, Chung WH, Chiu TM. Toxic epidermal necrolysis in an infant induced by drug intake through breast milk. Dermatol Sin 2019;37:86-9 Full text (link to original source)
  2. van Wattum JJ, Leferink TM, Wilffert B, Ter Horst PGJ. Antibiotics and lactation: An overview of relative infant doses and a systematic assessment of clinical studies. Basic Clin Pharmacol Toxicol. 2019 Jan;124(1):5-17. Abstract
  3. de Sá Del Fiol F, Barberato-Filho S, de Cássia Bergamaschi C, Lopes LC, Gauthier TP. Antibiotics and Breastfeeding. Chemotherapy. 2016;61(3):134-43. Abstract
  4. Butler DC, Heller MM, Murase JE. Safety of dermatologic medications in pregnancy and lactation: Part II. Lactation. J Am Acad Dermatol. 2014 Mar;70(3):417.e1-10; quiz 427. Abstract
  5. Amir LH; Academy of Breastfeeding Medicine Protocol Committee. ABM Clinical Protocol #4: Mastitis, Revised March 2014. Breastfeed Med. 2014;9(5):239-243. Abstract Full text (link to original source) Full text (in our servers)
  6. Amir LH. y el Comité de protocolos de la Academy of Breastfeeding Medicine. Protocolo clínico de la ABM n.o 4: Mastitis, modi cado en marzo de 2014. Breastfeed Med. 2014;9(5):239-243. Abstract Full text (link to original source) Full text (in our servers)
  7. Rowe H, Baker T, Hale TW. Maternal medication, drug use, and breastfeeding. Pediatr Clin North Am. 2013 Feb;60(1):275-94. Abstract
  8. Kong YL, Tey HL. Treatment of acne vulgaris during pregnancy and lactation. Drugs. 2013 Jun;73(8):779-87. Abstract
  9. Jahanfar S, Ng CJ, Teng CL. Antibiotics for mastitis in breastfeeding women. Cochrane Database Syst Rev. 2013 Feb 28; Abstract Full text (link to original source)
  10. Amir LH, Pirotta MV, Raval M. Breastfeeding--evidence based guidelines for the use of medicines. Aust Fam Physician. 2011 Sep;40(9):684-90. Review. Abstract Full text (link to original source) Full text (in our servers)
  11. Spencer JP. Management of mastitis in breastfeeding women. Am Fam Physician. 2008 Abstract Full text (link to original source) Full text (in our servers)
  12. Ilett KF, Hackett LP, Ingle B, Bretz PJ. Transfer of probenecid and cephalexin into breast milk. Ann Pharmacother. 2006 Abstract
  13. Benyamini L, Merlob P, Stahl B, Braunstein R, Bortnik O, Bulkowstein M, Zimmerman D, Berkovitch M. The safety of amoxicillin/clavulanic acid and cefuroxime during lactation. Ther Drug Monit. 2005 Abstract
  14. Bar-Oz B, Bulkowstein M, Benyamini L, Greenberg R, Soriano I, Zimmerman D, Bortnik O, Berkovitch M. Use of antibiotic and analgesic drugs during lactation. Drug Saf. 2003 Abstract
  15. Ito S, Blajchman A, Stephenson M, Eliopoulos C, Koren G. Prospective follow-up of adverse reactions in breast-fed infants exposed to maternal medication. Am J Obstet Gynecol. 1993 May;168(5):1393-9. Abstract
  16. Fulton B, Moore LL. Antiinfectives in breastmilk. Part I: Penicillins and cephalosporins. J Hum Lact. 1992 Abstract
  17. Matsuda S. Transfer of antibiotics into maternal milk. Biol Res Pregnancy Perinatol. 1984;5(2):57-60. Abstract
  18. Kafetzis DA, Siafas CA, Georgakopoulos PA, Papadatos CJ. Passage of cephalosporins and amoxicillin into the breast milk. Acta Paediatr Scand. 1981 Abstract

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