Transfer of risperidone and 9-hydroxyrisperidone into human milk.
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.


CONCLUSIONS
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.
Ilett
Kenneth F
KF
Pharmacology Unit, School of Medicine and Pharmacology, University of Western Australia, Crawley, Australia. kilett@receptor.pharm.uwa.edu.au
Hackett
L Peter
LP
Kristensen
Judith H
JH
Vaddadi
Krishna S
KS
Gardiner
Sharon J
SJ
Begg
Evan J
EJ
D000328:Adult; D019540:Area Under Curve; D001942:Breast Feeding; D019052:Depression, Postpartum / Q000188:drug therapy; D005260:Female; D005687:Galactorrhea / Q000139:chemically induced; D006801:Humans; D007223:Infant; D007555:Isoxazoles / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D008297:Male; D008895:Milk, Human / Q000737:chemistry*; D000068882:Paliperidone Palmitate; D011743:Pyrimidines / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D018967:Risperidone / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics
D007555:Isoxazoles; D011743:Pyrimidines; D018967:Risperidone; D000068882:Paliperidone Palmitate