CLAUDIA M. KLIER, M.D., NILUFAR MOSSAHEB, M.D., AMY LEE, M.Sc., GERALD ZERNIG, M.D.
Am J Psychiatry 164:348-a-349, February 2007
To the Editor: Selective serotonin reuptake inhibitors are the most studied antidepressants in breastfeeding mothers (1). However, to date, there is only one case report regarding mirtazapine and breastfeeding (2). This study found no clinically significant levels of mirtazapine in the milk, and serum concentrations in the infant were below therapeutic concentration. Breastmilk levels, assessed 15 and 22 hours postdose, were higher in hindmilk compared with foremilk. A fully breastfed infant would ingest 0.21%–1.02% of the weight-adjusted maternal dose on a daily basis, suggesting minimal exposure of mirtazapine to the infant.
However, infants may be exposed to higher levels, since serum mirtazapine concentrations peak at approximately 4 hours postdose. We report the case of evaluated mirtazapine levels in breastmilk at the time of expected maximum postdose plasma levels under the assumption that breastmilk levels peak at similar timepoints.