Transfer of risperidone and 9-hydroxyrisperidone into human milk

Ann Pharmacother. 2004 Feb;38(2):273-6. doi: 10.1345/aph.1D326. Epub 2003 Dec 30.


Objective: To quantify the transfer of risperidone and its active metabolite 9-hydroxyrisperidone into breast milk, estimate the amount the infant receives, measure infant plasma concentrations, and clinically assess the safety of breast feeding during maternal risperidone administration. case summaries: The transfer of risperidone and 9-hydroxyrisperidone into milk was studied in 2 breast-feeding women and one woman with risperidone-induced galactorrhea. Plasma samples were available from 2 of the women and from both breast-fed infants. The milk/plasma concentration ratio determined in 2 women was <0.5 for both compounds. The calculated relative infant "doses" were 2.3%, 2.8%, and 4.7% (as risperidone equivalents) of the maternal weight-adjusted doses. Risperidone and 9-hydroxyrisperidone were not detected in the plasma of the 2 breast-fed infants studied, and no adverse effects were noted.

Discussion: Risperidone therapy is sometimes necessary in breast-feeding women, raising the issue of safety in the exposed infants. Our study shows that the relative infant dose is lower than the arbitrary 10% level of concern. The data provide clear guidance on infant exposure for the cases presented.

Conclusions: Maternal risperidone therapy is unlikely to be a significant hazard for the breast-fed infant in the short term. Nevertheless, decisions on whether a woman may breast-feed should be made as an individual risk-benefit analysis.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Area Under Curve
  • Breast Feeding
  • Depression, Postpartum / drug therapy
  • Female
  • Galactorrhea / chemically induced
  • Humans
  • Infant
  • Isoxazoles / blood
  • Isoxazoles / metabolism*
  • Isoxazoles / pharmacokinetics
  • Male
  • Milk, Human / chemistry*
  • Paliperidone Palmitate
  • Pyrimidines / blood
  • Pyrimidines / metabolism*
  • Pyrimidines / pharmacokinetics
  • Risperidone / blood
  • Risperidone / metabolism*
  • Risperidone / pharmacokinetics


  • Isoxazoles
  • Pyrimidines
  • Risperidone
  • Paliperidone Palmitate