Last update: Dec. 23, 2015


Very Low Risk for breastfeeding

Safe. Compatible.
Minimal risk for breastfeeding and infant.

Excreted in non-significant levels into breast milk. No adverse effects have been shown in breastfed infants.

Caution with those neonates suffering of hyperbilirrubinemia or G-6-P-D deficiency is required. Avoid use in affected patients Check-up for infant jaundice.

Be aware of false negative results of bacterial cultures when the mother is on antibiotics.

American Academy of Pediatrics: Maternal Medication Usually Compatible With Breastfeeding.
Eleventh WHO Model List of Essential Drugs 2002: Compatible with breastfeeding.


Suggestions made at e-lactancia are done by APILAM´s pediatricians and pharmacists, and are based on updated scientific publications.
It is not intended to replace the relationship you have with your doctor but to compound it.

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

Sulfamethoxazole is also known as

Sulfamethoxazole in other languages or writings:


Sulfamethoxazole belongs to this group or family:


Main tradenames from several countries containing Sulfamethoxazole in its composition:

  • Abactrim™. Contains other elements than Sulfamethoxazole in its composition
  • Bactrim™. Contains other elements than Sulfamethoxazole in its composition
  • Cotribase
  • Cotrim™. Contains other elements than Sulfamethoxazole in its composition
  • Gamactrin
  • Gantanol
  • Pyramet™. Contains other elements than Sulfamethoxazole in its composition
  • Septrim™. Contains other elements than Sulfamethoxazole in its composition
  • Soltrim™. Contains other elements than Sulfamethoxazole in its composition


Variable Value Unit
Oral Bioavail. 100 %
Molecular weight 253 daltons
Protein Binding 62 - 70 %
Tmax 1 - 4 hours
T1/2 6 - 12 hours
M/P ratio 0,06 -
Theoretical Dose 0,8 mg/Kg/d
Relative Dose 1,2 - 5 %
Relat.Ped.Dose 2 %


  1. 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
  2. Mitrano JA, Spooner LM, Belliveau P. Excretion of antimicrobials used to treat methicillin-resistant Staphylococcus aureus infections during lactation: safety in breastfeeding infants. Pharmacotherapy. 2009 Sep;29(9):1103-9. Abstract
  3. Kaiser J, McPherson V, Kaufman L, Huber T. Clinical inquiries. Which UTI therapies are safe and effective during breastfeeding? J Fam Pract. 2007 Abstract
  4. Forna F, McConnell M, Kitabire FN, Homsy J, Brooks JT, Mermin J, Weidle PJ. Systematic review of the safety of trimethoprim-sulfamethoxazole for prophylaxis in HIV-infected pregnant women: implications for resource-limited settings. AIDS Rev. 2006 Abstract
  5. WHO / UNICEF. BREASTFEEDING AND MATERNAL MEDICATION Recommendations for Drugs in the Eleventh WHO Model List of Essential Drugs. Department of Child and Adolescent Health and Development (WHO/UNICEF) 2002 Full text (link to original source) Full text (in our servers)
  6. AAP - American Academy of Pediatrics Committee on Drugs. Transfer of drugs and other chemicals into human milk. Pediatrics. 2001 Sep;108(3):776-89. Abstract Full text (link to original source) Full text (in our servers)
  7. Chin KG, McPherson CE 3rd, Hoffman M, Kuchta A, Mactal-Haaf C. Use of anti-infective agents during lactation: Part 2--Aminoglycosides, macrolides, quinolones, sulfonamides, trimethoprim, tetracyclines, chloramphenicol, clindamycin, and metronidazole. J Hum Lact. 2001 Feb;17(1):54-65. Abstract
  8. 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
  9. Miller RD, Salter AJ. \ The passage of trimethoprim/sulpha-methoxazole into breast milk and its significance. \ Proceedings of the 8th International Congress of Chemotherapy, Athens. Hellenic Soc Chemother. 1974;1:687. 1974
  10. Rasmussen F. \ Mammary excretion of sulphonamides. Acta Pharmacol Toxicol 1958; 15: 139-48. 1958

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e-lactancia is a resource recommended by Confederación Nacional de Pediatría (CONAPEME) from Mexico

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