Last update Dec. 7, 2016

Olsalazine Sodium


Safe substance and/or breastfeeding is the best option.

Prodrug of Mesalazine: Medication compounded by union of two molecules of 5-ASA resulting in a dimer which is degraded into monomeric Mesalazine (5-ASA) in the large intestine.

Mesalazine is badly absorbed by the intestine, serum levels are low with scant excretion into breast milk. Traces of Olsalazine and/or Mesalazine have not been found in breast milk of treated mothers with Olsalazine. N-acetyl-5-ASA is an inactive metabolite which is excreted into breast milk but not higher than 1% of relative infant's dose.

No harm effects among breastfed infants from treated mothers have been reported, except for rare cases of diarrhea reported in the 80's with the use of Mesalazine compounds different to Olsalazine. In a review of 121 cases and 121 controls, the authors failed to observe those findings. (Moretti, 1989).

Expert consensus supports the compatibility of Mesalazine and/or its prodrugs during breastfeeding.


We do not have alternatives for Olsalazine Sodium 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

Olsalazine Sodium is also known as Olsalazine.

Olsalazine Sodium in other languages or writings:


Main tradenames from several countries containing Olsalazine Sodium in its composition:


Variable Value Unit
Oral Bioavail. 2.4 %
Molecular weight 346 daltons
Protein Binding 99 %
Tmax 1 - 2 hours
0.9 hours
Theoretical Dose 0.06 mg/Kg/d
Relative Dose 0.4 %


  1. McConnell RA, Mahadevan U. Pregnancy and the Patient with Inflammatory Bowel Disease: Fertility, Treatment, Delivery, and Complications. Gastroenterol Clin North Am. 2016 Abstract
  2. van der Woude CJ, Kolacek S, Dotan I, Oresland T, Vermeire S, Munkholm P, Mahadevan U, Mackillop L, Dignass A; European Crohn's Colitis Organisation (ECCO). European evidenced-based consensus on reproduction in inflammatory bowel disease. J Crohns Colitis. 2010 Abstract Full text (link to original source) Full text (in our servers)
  3. Mottet C, Vader JP, Felley C, Froehlich F, Gonvers JJ, Juillerat P, Stockbrügger R, Angelucci E, Seibold F, Michetti P, Pittet V; EPACT II Study Group. Appropriate management of special situations in Crohn's disease (upper gastro-intestinal; extra-intestinal manifestations; drug safety during pregnancy and breastfeeding): Results of a multidisciplinary international expert panel-EPACT II. J Crohns Colitis. 2009 Abstract Full text (link to original source) Full text (in our servers)
  4. Dignass AU, Hartmann F, Sturm A, Stein J. Management of inflammatory bowel diseases during pregnancy. Dig Dis. 2009 Abstract
  5. Mottet C, Juillerat P, Pittet V, Gonvers JJ, Froehlich F, Vader JP, Michetti P, Felley C. Pregnancy and breastfeeding in patients with Crohn's disease. Digestion. 2007 Abstract
  6. Mahadevan U, Kane S. American gastroenterological association institute technical review on the use of gastrointestinal medications in pregnancy. Gastroenterology. 2006 Jul;131(1):283-311. Review. Abstract Full text (link to original source) Full text (in our servers)
  7. Silverman DA, Ford J, Shaw I, Probert CS. Is mesalazine really safe for use in breastfeeding mothers? Gut. 2005 Abstract Full text (link to original source) Full text (in our servers)
  8. Kanenguiser P, Goyheneche B, Filinger E. Aminosalicilatos: Características de las Formulaciones Orales Utilizadas en el Tratamiento de la Enfermedad Inflamatoria Intestinal. Lat. Am. J. Pharm. 22 (3): 255-60 2003 Full text (link to original source) Full text (in our servers)
  9. Barriuso LM, Yoldi-Petri ME, Olaciregui O, Iceta-Lizarraga A, Goñi-Orayen C. Trombosis del seno longitudinal superior en un lactante: ¿secundaria a una exposición prolongada a mesalazina? [Thrombosis of the superior sagittal sinus in a breast fed infant: secondary to prolonged exposure to mesalazine?]. Rev Neurol. 2003 Jun 16-30;36(12):1142-4. Spanish. Abstract
  10. Moretti Myla Emily. Prospective follow-up of infants exposed to 5-aminosalicylic acid containing drugs through maternal milk. Thesis. Department of Pharmacology \ University of Toronto 1998 Full text (link to original source) Full text (in our servers)
  11. Connell WR. Safety of drug therapy for inflammatory bowel disease in pregnant and nursing women. Inflamm Bowel Dis. 1996 Abstract
  12. Christensen LA, Rasmussen SN, Hansen SH. Disposition of 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid in fetal and maternal body fluids during treatment with different 5-aminosalicylic acid preparations. Acta Obstet Gynecol Scand. 1994 May;73(5):399-402. Abstract
  13. Miller LG, Hopkinson JM, Motil KJ, Corboy JE, Andersson S. Disposition of olsalazine and metabolites in breast milk. J Clin Pharmacol. 1993 Abstract
  14. Klotz U, Harings-Kaim A. Negligible excretion of 5-aminosalicylic acid in breast milk. Lancet. 1993 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. Jenss H, Weber P, Hartmann F. 5-Aminosalicylic acid and its metabolite in breast milk during lactation. Am J Gastroenterol. 1990 Abstract
  17. Nelis GF. Diarrhoea due to 5-aminosalicylic acid in breast milk. Lancet. 1989 Abstract
  18. Ambrosius Christensen L, Rasmussen SN, Hansen SH, Bondesen S, Hvidberg EF. Salazosulfapyridine and metabolites in fetal and maternal body fluids with special reference to 5-aminosalicylic acid. Acta Obstet Gynecol Scand. 1987 Abstract
  19. Klotz U. Clinical pharmacokinetics of sulphasalazine, its metabolites and other prodrugs of 5-aminosalicylic acid. Clin Pharmacokinet. 1985 Abstract

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