Lithium in breast milk and nursing infants: clinical implications.
OBJECTIVE
Current practice guidelines discourage use of lithium during breast-feeding, despite limited data. This study aimed to quantify lithium exposure in nursing infants.


METHODS
In 10 mother-infant pairs, the authors obtained assays of lithium in maternal serum, breast milk, and infant serum and indices of infant renal and thyroid function.


RESULTS
Maternal serum, breast milk, and infant serum daily trough concentrations of lithium averaged 0.76, 0.35, and 0.16 meq/liter, respectively, each lithium level lower than the preceding level by approximately one-half. No serious adverse events were observed, and elevations of thyroid-stimulating hormone, blood urea nitrogen, and creatinine were few, minor, and transient.


CONCLUSIONS
Serum lithium levels in nursing infants were low and well tolerated. No significant adverse clinical or behavioral effects in the infants were noted. These findings encourage reassessment of recommendations against lithium during breast-feeding and underscore the importance of close clinical monitoring of nursing infants.
Viguera
Adele C
AC
Perinatal and Reproductive Psychiatry Clinical Research Program, Department of Psychiatry, Massachusetts General Hospital, Simches Research Bldg., Second Fl., Suite 2200, 185 Cambridge St., Boston, MA 02114, USA. aviguera@partners.org
Newport
D Jeffrey
DJ
Ritchie
James
J
Stowe
Zachary
Z
Whitfield
Theodore
T
Mogielnicki
Juliana
J
Baldessarini
Ross J
RJ
Zurick
Amanda
A
Cohen
Lee S
LS
D001714:Bipolar Disorder / Q000097:blood / Q000188:drug therapy*; D001806:Blood Urea Nitrogen; D001942:Breast Feeding; D003401:Creatine / Q000097:blood; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn / Q000097:blood*; D007677:Kidney Function Tests; D007774:Lactation / Q000097:blood; D018020:Lithium Compounds / Q000009:adverse effects / Q000032:analysis* / Q000097:blood*; D008431:Maternal-Fetal Exchange; D008895:Milk, Human / Q000737:chemistry*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000188:drug therapy*; D011644:Puerperal Disorders / Q000097:blood / Q000188:drug therapy; D013972:Thyrotropin / Q000097:blood
D018020:Lithium Compounds; D013972:Thyrotropin; D003401:Creatine