Therapeutic drug monitoring of psychotropic medication during pregnancy and lactation

Abstract

Using psychotropic drugs for the treatment of pregnant and lactating women is a relatively common practice. However, administering psychotropic medication during this period must follow an individual risk-benefit assessment in which the apparent risks associated with fetal or neonatal drug exposure are weighted against the risks of leaving the mental illness untreated. It is not only essential to choose the drugs that bear the lowest risks for the child but also to know the optimal dose. Therapeutic drug monitoring (TDM) is a tool to better individualize dosing regimens. This is of major importance as during pregnancy considerable physiologic changes in absorption, distribution, metabolism and elimination of drugs affecting individual drug concentrations appear. The activity of some CYP isoenzymes and the renal clearance change during pregnancy, both considerably affect the plasma levels of a number of psychotropic drugs. During the breastfeeding period, the factors promoting the transition of psychotropic drugs into the milk need to be considered. However, and more importantly, the metabolism of the individual child determines the infant plasma level and therefore the risk for the child. A TDM routine in patients under psychotropic medication during pregnancy and the breastfeeding period is highly recommended.