Also known as Anhydrous cefalexin, Anhydrous cephalexin, Cefalexin, Cefalexin anhydrous, Cefalexina, Cefalexinum, Cephalexin anhydrous, Céfalexine, Keflex
A beta-lactam, first-generation cephalosporin antibiotic with bactericidal activity. Cephalexin binds to and inactivates penicillin-binding proteins (PBP) located on the inner membrane of the bacterial cell wall. Inactivation of PBPs interferes with the cross-linking of peptidoglycan chains necessary for bacterial cell wall strength and rigidity. This results in the weakening of the bacterial cell wall and causes cell lysis. Compared to second and third generation cephalosporins, cephalexin is more active against gram-positive and less active against gram-negative organisms.
Originator: NCI Thesaurus | Source: The website of the National Cancer Institute (http://www.cancer.gov)
Can I take Cephalexin while breastfeeding?
Cephalexin is acceptable to use during breastfeeding. Limited information indicates that maternal doses of cephalexin up to 1 gram produce low levels in milk that are not expected to cause adverse effects in breastfed infants. Occasionally, disruption of the infant’s gastrointestinal flora, resulting in diarrhea or thrush, has been reported with cephalosporins, but these effects have not been adequately evaluated.
Drug levels
Maternal Levels. After a single 1 gram oral dose of cephalexin in 6 women who were 2 days postpartum, peak milk levels occurred 4 to 5 hours after the dose and averaged 0.51 mg/L (range 0.24 to 0.85 mg/L).[1]
After a single 500 mg oral dose of cephalexin in 2 women (time postpartum not stated), peak milk levels of 0.7 mg/L occurred 4 hours after the dose.[2]
A woman who was 28 days postpartum had been taking oral cephalexin 500 mg plus probenecid 500 mg 4 times daily for 16 days collected 12 fore-and hindmilk samples over a 16-hour period. Milk cephalexin levels ranged from about 400 to 1000 mcg/L over the milk collection period with little correlation to the times of the doses. The authors calculated that an exclusively breastfed infant would receive 112 mcg/kg daily which is much less than the recommended infant dosage of 25 to 100 mg/kg daily. The infant dosage in milk corresponds to about 0.5% of the maternal weight-adjusted dosage which is higher than in previous reports.[3] The higher milk levels in this patient may have been a result of the concurrent probenecid use.
Infant Levels. Relevant published information was not found as of the revision date.
Effects in breastfed infants
Maternal Levels. After a single 1 gram oral dose of cephalexin in 6 women who were 2 days postpartum, peak milk levels occurred 4 to 5 hours after the dose and averaged 0.51 mg/L (range 0.24 to 0.85 mg/L).[1]
After a single 500 mg oral dose of cephalexin in 2 women (time postpartum not stated), peak milk levels of 0.7 mg/L occurred 4 hours after the dose.[2]
A woman who was 28 days postpartum had been taking oral cephalexin 500 mg plus probenecid 500 mg 4 times daily for 16 days collected 12 fore-and hindmilk samples over a 16-hour period. Milk cephalexin levels ranged from about 400 to 1000 mcg/L over the milk collection period with little correlation to the times of the doses. The authors calculated that an exclusively breastfed infant would receive 112 mcg/kg daily which is much less than the recommended infant dosage of 25 to 100 mg/kg daily. The infant dosage in milk corresponds to about 0.5% of the maternal weight-adjusted dosage which is higher than in previous reports.[3] The higher milk levels in this patient may have been a result of the concurrent probenecid use.
Infant Levels. Relevant published information was not found as of the revision date.
Possible effects on lactation
Relevant published information was not found as of the revision date.
References
1. Kafetzis DA, Siafas CA, Georgakopoulos PA et al. Passage of cephalosporins and amoxicillin into the breast milk. Acta Paediatr Scand. 1981;70:285-8. PMID: 7246123
2. Matsuda S. Transfer of antibiotics into maternal milk. Biol Res Pregnancy. 1984;5:57-60. PMID: 6743732
3. Ilett KF, Hackett LP, Ingle B et al. Transfer of probenecid and cephalexin into breast milk. Ann Pharmacother. 2006;40:986-9. PMID: 16551765
4. Ito S, Blajchman A, Stephenson M et al. Prospective follow-up of adverse reactions in breast-fed infants exposed to maternal medication. Am J Obstet Gynecol. 1993;168:1393-9. PMID: 8498418
5. Benyamini L, Merlob P, Stahl B et al. The safety of amoxicillin/clavulanic acid and cefuroxime during lactation. Ther Drug Monit. 2005;27:499-502. PMID: 16044108
Last Revision Date
20130907
Disclaimer:Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.
Source: LactMed – National Library of Medicine (NLM)