Motives for investing in TDM and Pharmacogenetic Tests when Treating Patients at Risk

Therapeutic Drug Monitoring (TDM) and pharmacogenetic tests of polymorphic cytochrome P-450 (CYP) isoenzymes (mainly CYP2D6 and CYP2C19 today) are becoming more and more relevant for application in routine clinical psychiatric practice. Hence, the necessity for investigations of TDM- and CYP-determinations when applied in clinical trials phase IV has become an amendable task of further focus for practicing clinical pharmacologists and laboratories offering TDM-services to psychiatry. However, since many of the aspects relevant for the TDM-outcome and its tentative link to CYP-expression are related to e.g. non-compliance issues and prevailing polypharmacy strategies in the everyday clinical practice, such investigations has to assess not only studies based on traditional protocols for phase-IV trials. In the present lecture, therefore, introduction of the concept of TDM-„nouveau“ and its bearing on novel designs for evaluating the basic such pharmacokinetics of newer psychoactive drugs when exposed to the naturalistic clinical setting will be forwarded. The role for this type of TDM as well as evaluation of its implementation with or without pharmacogenetic tests for CYP-polymorphism will be discussed.