Establishing therapeutic drug monitoring to routinely assess pharmacokinetic changes for psychotropic medications prescribed during pregnancy and lactation

Therapeutic drug monitoring (TDM) has been employed to assess alterations in pharmacokinetics of psychotropic medications due to the physiological changes of pregnancy over the past decades. Here we present an approach to quantify the pregnancy impact on the pharmacokinetics of antidepressants, lithium and antiseizure medications.

We performed systematic literature searches to identify TDM studies comparing levels of antidepressants and antiseizure medications as well as lithium in the same woman in the preconception/postpartum period and during pregnancy. Accordingly, we estimated alteration ratios for dose-adjusted plasma concentrations (C/D ratios) between the 3rd trimester and preconception/postpartum period. The quality of the included studies was assessed using the ClinPK guidelines

A total of 81 studies investigating 15 antiseizure medications, 11 antidepressants and lithium were included. Among antiseizure medications, the largest differences were reported for lamotrigine (n=188, alteration ratio 0.4, range 0.1-2.4), whereas among antidepressants the largest difference was reported for nortriptyline (n=7, alteration ratio 0.5, range 0.3-0.7). The quality of studies was invariably acceptable.

Using TDM evidence we reported large changes in pharmacokinetics during pregnancy for several antiseizure medications and antidepressants, which could severely impact treatment outcomes. Thus, TDM should be considered as an essential routine tool of pharmacotherapy for women during pregnancy and lactation.

Publication History

Article published online:
12 March 2024