Therapeutic Drug Monitoring (TDM) During Pregnancy and Breast Feeding

Abstract

Epidemiological data indicate that about one third of all pregnant women receive at least one psychotropic drug (Goldberg & Nissim 1994). Women with mental disorders bear a considerable risk of relapse when psychotropic medication is discontinued during pregnancy and the postpartal period.

TDM aims to better individualize dosing regimens taking into account relevant pregnancy-induced metabolism returning to baseline activities within 24 hours (Adab 2006).

Despite the frequent use of psychotropic drugs in pregnancy, for several psychotropic drugs only few documented cases regarding their influence on organogenesis, delivery complications or long term effects are available. Therefore, one should follow some general guidelines when treating pregnant women (cf. Bergemann & Conca). Furthermore, it is recommended to guide any psychopharmacological therapy by TDM. TDM in pregnant women and/or mothers is recommended to be carried out at least once per trimester and within 24 hours after delivery. For TDM at delivery umbilical cord blood of neonates exposed in utero to psychotropic drugs should be collected, since possible neonatal symptoms has to be differentiated from a withdrawal syndrome versus toxic effects of the substances (cf. Koren 2006, Pakalapati et al. 2006).

The use of psychotropic medications during breast-feeding has some implications. All psychotropic medications enter breast milk. However, current data do not support monitoring breast milk levels in attempt to estimate individual infant plasma levels, since the effective drug concentration in the neonate is essentially determined by its own metabolism (Weissman et al. 2004). A systematic monitoring of mother and child including TDM is recommended.