DRUG CONCENTRATIONS IN BLOOD AND BREAST MILK WHILE TAKING PSYCHOTROPIC DRUGS-PRELIMINARY STUDY-

Abstract Background The perinatal period is a time when psychiatric disorders frequently occur. Promotion of breastfeeding is recommended by WHO and other organizations, and is considered important for mother-infant attachment formation, but expectant mothers taking psychotropic drugs tend to avoid breastfeeding due to less accurate information. Currently, scientific and empirical data on breastfeeding are available, but these data are limited. We report here the results of a study to determine drug concentrations in the blood and breast milk of lactating women taking psychotropic drugs. Aims & Objectives This study was approved by the Ethics Committee of Shiga University of Medical Science. The subjects were lactating women undergoing treatment at the Department of Psychiatry, Shiga University Hospital, and consent for the study was obtained in writing before the study was conducted. Blood levels of medications were measured by liquid chromatography/tandem mass spectrometry at the Department of Pharmaceutical Sciences, Tohoku University Hospital. Blood samples were taken at 6:00 in the morning, and breast milk was collected on the same day as the blood samples. Results The subjects were those who had been taking brocizolam before pregnancy and those who had been taking lorazepam 0.5 mg as an abortive dose. The blood concentration of brocizolam was 5.12 ng/ml, which was within the therapeutic range. However, it was not detected in breast milk. As for lorazepam, it was lower than the recommended concentration from Therapeutic Drug Monitoring for blood levels (1), and it is also low in breast milk. We will present the results of other psychotropic medications at the meeting. Discussion & Conclusion The blood and breast milk concentrations of patients taking psychotropic drugs were measured. The data of brotizolam is not listed on Hale's Medications Mother's Milk2023 which is often used to determine the acceptability of breastfeeding. The package inserts for many benzodiazepines state that they may pass into human milk and cause lethargy, weight loss, etc. in newborns. In fact, the package insert for brotizolam also states that breastfeeding should be avoided, but it was suggested that the effect on the infant might be low. Lorazepam was also detected, but at low levels. Both of these medications might appear to be safe to administer to nursing mothers. We will increase the number of cases and measure multiple psychotropic drugs in the future. References (1)Hiemke C, Bergemann N, Clement HW, et al. 2018. Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology: Update 2017. Pharmacopsychiatry. 51(1-02):9-62