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This monograph summarizes the toxicological‑lactological profile of medicines classified under ATC class A07E (intestinal anti‑inflammatory agents) for use during breastfeeding, with focus on risk assessment for the breastfed infant and lactating parent.atcddd.fhi+4

Classification and therapeutic group

ATC class A07E comprises intestinal anti‑inflammatory agents within the broader group A07 “Antidiarrheals, intestinal anti‑inflammatory/anti‑infective agents” of the WHO Anatomical Therapeutic Chemical Classification System.atcddd.fhi+3
The group includes locally acting corticosteroids (A07EA) and aminosalicylic acid derivatives and similar agents (A07EC), mainly indicated for inflammatory bowel disease such as ulcerative colitis and Crohn’s disease.atcddd.fhi+3

Main active substances

Locally acting corticosteroids in A07EA include prednisolone, hydrocortisone, prednisone, betamethasone, tixocortol, budesonide and beclometasone formulated for intestinal or rectal use (e.g. enemas, rectal foams, oral preparations with poor systemic availability and gut‑targeted release).atcddd.fhi+3
Aminosalicylate products in A07EC comprise sulfasalazine, mesalazine (5‑aminosalicylic acid), olsalazine, balsalazide and similar derivatives designed for local anti‑inflammatory action in the intestinal lumen and mucosa.wikipedia+2

Mechanism of action and clinical use

Intestinal corticosteroids exert topical glucocorticoid effects on the gut mucosa, reducing inflammatory cell infiltration, cytokine production and mucosal edema, while systemic exposure is limited by poor absorption or extensive first‑pass metabolism.atcddd.fhi+1
Aminosalicylates act predominantly via inhibition of cyclo‑oxygenase and lipoxygenase pathways, modulation of prostaglandins and leukotrienes, and interference with inflammatory transcription factors, thereby controlling mucosal inflammation in mild to moderate inflammatory bowel disease.pregnancy.ibdclinic+1

Pharmacokinetics relevant to lactation

Locally acting corticosteroids (e.g. budesonide, rectal prednisone/hydrocortisone) are formulated to maximize intestinal topical action and minimize systemic bioavailability, which limits transfer into breast milk, though low maternal plasma levels can still lead to small milk concentrations.atcddd.fhi+2
Aminosalicylates such as mesalazine and sulfasalazine have limited systemic absorption of the active 5‑ASA fraction; they are excreted into breast milk in small amounts, but metabolites like N‑acetyl‑5‑ASA and sulfapyridine can reach measurable milk and infant serum levels.pubmed.ncbi.nlm.nih+1

Excretion into breast milk

Clinical and pharmacokinetic data indicate that mesalazine and sulfasalazine are poorly excreted into breast milk, with low levels of the parent drug but relatively higher levels of some inactive or less active metabolites.pubmed.ncbi.nlm.nih+1
Locally acting corticosteroids used for inflammatory bowel disease (e.g. budesonide, prednisone) appear in breast milk in small quantities; peak concentrations occur within the first hours after maternal ingestion, and overall infant exposure is considered low.pregnancy.ibdclinic

Observed effects in breastfed infants

For sulfasalazine, rare adverse events have been reported, including bloody diarrhea and potential hemolysis in infants, particularly in those with glucose‑6‑phosphate dehydrogenase (G6PD) deficiency, linked to sulfapyridine exposure.pubmed.ncbi.nlm.nih
For mesalazine and related aminosalicylates, sporadic cases of diarrhea in breastfed infants have been described, but the overall incidence is low and most exposed infants remain asymptomatic.pubmed.ncbi.nlm.nih+1

Risk assessment and safety profile

Multiple expert reviews and guidelines consider sulfasalazine and mesalazine to be low‑risk medications during breastfeeding when clinically indicated for inflammatory bowel disease, provided infants are monitored for gastrointestinal symptoms and, in the case of sulfasalazine, for signs of hemolysis.pubmed.ncbi.nlm.nih+2
Intestinal corticosteroids such as budesonide and prednisone used for inflammatory bowel disease are generally regarded as compatible with breastfeeding, with minimal risk to the infant due to low milk levels, although careful clinical observation is recommended, especially in very young or medically fragile infants.pregnancy.ibdclinic

Clinical monitoring recommendations

When the lactating parent is treated with A07E aminosalicylates, the breastfed infant should be monitored for diarrhea, poor feeding, vomiting, rash or unusual irritability, and medical evaluation obtained if such symptoms appear.pubmed.ncbi.nlm.nih+2
In infants of mothers receiving sulfasalazine, particular attention should be paid to signs of hemolytic anemia (e.g. pallor, jaundice, dark urine), especially in the neonatal period and in populations with higher prevalence of G6PD deficiency.pubmed.ncbi.nlm.nih

Considerations for therapy continuation

Available evidence suggests that treatment of inflammatory bowel disease with A07E agents during lactation is usually compatible with continued breastfeeding, and discontinuation of breastfeeding is not routinely required when these medications are clinically necessary.pubmed.ncbi.nlm.nih+2
Maintaining adequate disease control in the lactating parent is important for maternal health and caregiving capacity; under‑treatment of inflammatory bowel disease may pose greater overall risk than the low‑level infant exposure to these drugs through breast milk.ephmra+1

Preferred options within class

For aminosalicylates, mesalazine and other derivatives without sulfonamide components are generally preferred over sulfasalazine during breastfeeding, due to lower theoretical risk of sulfonamide‑related adverse effects, while still providing effective mucosal anti‑inflammatory action.pubmed.ncbi.nlm.nih+1
Choice among intestinal corticosteroids (e.g. budesonide versus systemic prednisone) should consider disease location, formulation, maternal dose and potential systemic exposure, aiming for the lowest effective dose and, when feasible, timing doses immediately after breastfeeding to reduce peak milk levels.atcddd.fhi+2

Summary of lactational risk

Overall, A07E intestinal anti‑inflammatory agents are associated with low to moderate theoretical risk in breastfeeding, with most guidelines supporting their use when indicated, under infant monitoring for gastrointestinal symptoms and hematological adverse effects.pubmed.ncbi.nlm.nih+2
Careful individual risk–benefit assessment, consideration of infant age and comorbidities, and coordination between gastroenterology and lactation‑support services are essential components of safe use of this class during lactation.pubmed.ncbi.nlm.nih+2