Last update Oct. 14, 2022


Very Low Risk

Safe. Compatible. Minimal risk for breastfeeding and infant.

It is an isoxazolylpenicillin used for the treatment of benzylpenicillin-resistant staphylococcal infections. Oral, intramuscular or intravenous administration.

Like most penicillin-type antibiotics, excretion into breast milk is clinically non-significant. (Griffiths1978)

Although rare, the possibility of transient gastroenteritis due to alteration of the intestinal flora in infants whose mothers take antibiotics should be taken into account. (Ito 1993) 

Widely used for treatment of Mastitis since it has an effective activity against Staphylococcus. Several medical societies and expert authors consider the use of this medication to be safe during breastfeeding. (Amir 2014 y 2011, Spencer 2008, Nordeng 2003, Bodley 2000, Dixon 1988)


We do not have alternatives for Flucloxacillin since it is relatively safe.

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

Flucloxacillin is also known as

Flucloxacillin in other languages or writings:


Flucloxacillin belongs to this group or family:


Main tradenames from several countries containing Flucloxacillin in its composition:


Variable Value Unit
Oral Bioavail. 50 - 70 %
Molecular weight 454 daltons
Protein Binding 95 %
VD 0.1 l/Kg
pKa 3.75 -
Tmax 1 hours
0.75 - 1 hours
Theoretical Dose 0.015 mg/Kg/d
Relative Dose 0.36 %


  1. 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)
  2. 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)
  3. Spencer JP. Management of mastitis in breastfeeding women. Am Fam Physician. 2008 Abstract Full text (link to original source) Full text (in our servers)
  4. Nordeng H, Tufte E, Nylander G. [Treatment of mastitis in general practice]. Tidsskr Nor Laegeforen. 2003 Abstract
  5. Bodley V, Powers D. Case management of a breastfeeding mother with persistent oversupply and recurrent breast infections. J Hum Lact. 2000 Abstract
  6. 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
  7. Dixon JM. Repeated aspiration of breast abscesses in lactating women. BMJ. 1988 Abstract Full text (link to original source) Full text (in our servers)
  8. Matsuda S. Transfer of antibiotics into maternal milk. Biol Res Pregnancy Perinatol. 1984;5(2):57-60. Abstract
  9. Griffiths AD, Bull FE. Sweat testing for cystic fibrosis. Arch Dis Child. 1978 Nov;53(11):918. No abstract available. Abstract Full text (link to original source)

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e-lactancia is a resource recommended by Academy of Breastfeeding Medicine - 2006 of United States of America

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