Lurasidone in lactation: A case study with laboratory and clinical outcomes

Abstract

We report a case of lurasidone use in a mother who was exclusively breastfeeding, with no signs of infant toxicity for 39 days post-partum, and a relative infant dose (RID) of 0.29%. Lurasidone is a novel second-generation antipsychotic, with a favourable metabolic profile (Javed et al., 2019). Given the ever-clearer link between some second-generation antipsychotics and gestational diabetes (Galbally et al., 2020), there is a search for alternatives in the peripartum period. Antipsychotic lactation safety data is urgently required in order to safely prevent and treat post-partum illness episodes in patients with mood and psychotic disorders and to allow maintenance of breastfeeding for infants and their mothers. Lurasidone may sequester in breast milk as it is a small molecule, lipophilic and a weak base, with a fairly long elimination half-life of 18–40 hours. On the contrary, it is highly protein bound at 99%. It has fairly low oral bioavailability compared to other antipsychotics, plasma levels peak at 1–3 hours and steady state is reached within 7 days. Lurasidone undergoes hepatic metabolism via cytochrome P450 3A4, which does not significantly vary in effect between individuals (Greenberg and Citrome, 2017). Rat data indicate breast milk-to-maternal serum ratio of 7:1 at 1 hour, 13:1 at 2 hours and 4:1 at 24 hours. There are no data for rat pup serum levels (Sunovion Pharmaceuticals Inc, 2009).