Olanzapine treatment during breast feeding: a case report.

Postpartum psychosis constitutes a severe complication that entails risk for both mother and child. Little is known about the use of olanzapine in the treatment of postpartum psychosis. In previous studies, it has been reported on mothers receiving relatively low doses of olanzapine. We report a 38-year-old patient who was admitted to the hospital for an acute psychotic exacerbation. She was breast feeding her 5-month-old child, and she wished to continue breast feeding. Olanzapine treatment was started with a daily dosage of 15 mg. The weight-corrected maternal dose was 270 mug/kg. The olanzapine concentration in the mother's plasma was 24 ng/mL. The analysis of olanzapine in breast milk applying two different high-performance liquid chromatography procedures revealed similar results: 12.2 ng/g without and 11.5 ng/g with additional hydrochloric acid extraction, respectively. In addition, breast milk of an unmedicated mother was used for establishing the analytical procedure so that the validity of the results was better confirmed. The milk-plasma ratio arising from our data was 0.5, and the relative infant dose was 0.3%. The olanzapine concentration was below the limit of detection (<5 ng/mL) in the infant's plasma sample. No adverse effects were noticed, and the mother experienced a rapid improvement in her psychopathology during her hospital stay. In future studies, long-term follow-up of both mother and child would be useful.