Olanzapine Relatively Safe During Breast-Feeding

Laurie Barclay, MD

August 08, 2003

Aug. 8, 2003 — Only a small amount of olanzapine transfers from mother to baby during breast-feeding, according to the results of a small trial published in the August issue of the American Journal of Psychiatry. The investigators suggest that it is relatively safe to breast-feed while taking this medication but that mothers should avoid doing so during the peak levels achieved within five hours postdose.

"The incidence of psychiatric disorders is at its peak during the postpartum period, with up to 20% of mothers affected," write Sharon J. Gardiner, MClinPharm, from Christchurch Hospital in New Zealand, and colleagues. "The use of olanzapine in the treatment of postpartum psychosis has been limited by sparse data on its transfer into breast milk and on the effects of exposure to the drug on a suckling infant."

In seven mother-infant nursing pairs, high-performance liquid chromatography revealed that the median infant dose of olanzapine ingested through milk was 1.02% of the maternal dose. Maximum relative infant dose was approximately 1.2%. The authors point out that these ratios are much lower than the national cutoff of 10.0% used to guide drug safety during breast-feeding.

In six patients with data collected over the dose interval, the median milk-to-plasma area-under-the-curve ratio was 0.38. Six infants with an evaluable plasma sample had undetectable levels of olanzapine. All of the infants were healthy and had no apparent adverse events.

"These data support the use of olanzapine during breast-feeding," the authors write. "However, the authors recommend that breast-fed infants be monitored closely and the decision to breast-feed be made after individual risk-benefit analysis."

The Women and Infants Research Foundation in Subiaco, Western Australia, helped fund this study.

Am J Psychiatry. 2003;160:1428-1431

Reviewed by Gary D. Vogin, MD


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