Pregnancy and antipsychotics

Background: When women, diagnosed with shizophrenia, are pregnant, often uncertainty arises about the further drug treatment. Casuistry: We present the case of a 41-year-old patient, who suffers from paranoid schizophrenia and gets the depot neuroleptic olanzapine pamoate since 2012 at our institute outpatient regularly. She informed us that she is 26 weeks pregnant as she came to the regular drug injection date. We report about the outpatient treatment with olanzapine pamoate up to the 32th week of pregnancy and the successive plasma concentrations. In the following 2 half-life periods, the last 60 days of pregnancy, the plasma concentration of olanzapine, over 9 subsequently made measurements, decreased from 20 ng/ml to 8.7 ng/ml (reference range [5–75 ng/ml]) in the mothers blood. In the umbilical cord 4.8 ng/ml olanzapine pamoate were determined. Conclusion: In order to ensure optimal protection for mother and child, additionally to an interdisciplinary treatment, knowledge of the modifying pharmacodynamics is necessary. The decreased activity of CYP1A2 and the long half-life period, require, even after ending the depot medication, a very slow effective level waste. Because during pregnancy also the plasma protein binding is reduced, the rate of the free olanzapine increases. Therefore, under therapeutic drug monitoring (TDM) and finer psychiatric exploration, low level olanzapine should be tolerated when pregnant women with schizophrenia are treated.