Aminosalicylic Acid

Drug Levels and Effects:

Summary of Use during Lactation:

Limited information indicates that maternalaminosalicylicacidtherapy produces low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. Exclusively breastfed infants should be monitored for rare instances of jaundice, gastrointestinal disturbances, hypokalemia, thrombocytopenia, hemolysis and hypokalemia if this drug is used during lactation.[1]

Drug Levels:

Maternal Levels.

One woman who was lactating, but not breastfeeding (time postpartum not stated) took a single 4 gram oral dose ofaminosalicylicacid. A peak milk level of 1.1 mg/L occurred at 3 hours after the dose. The drug's half-life in milk was estimated to be 2.5 hours.[1] Using these data, a fully breastfed infant would receive a maximum of about 0.25% of the maternal weight-adjusted dosage.

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

Aminosalicylicacidwas used as part of multi-drug regimens to treat 2 pregnant women with multidrug-resistant tuberculosis throughout pregnancy and postpartum. Their two infants were breastfed (extent and duration not stated). At age 1.8 and 4.6 years, the children were developing normally, except for except for a mild speech delay in one and At age 1.8 years, failure to thrive in the other, possibly due to tuberculosis contracted after birth.[2]

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.


1. Holdiness MR. Antituberculosis drugs and breast-feeding. Arch Intern Med. 1984;144:1888. Letter. PMID:15889370
2. Drobac PC, del Castillo H, Sweetland A et al. Treatment of multidrug-resistant tuberculosis during pregnancy: long-term follow-up of 6 children with intrauterine exposure to second-line agents. Clin Infect Dis. 2005;40:1689-92. PMID:15889370

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Antitubercular Agents

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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