The future of therapeutic drug monitoring in clinical practice

Therapeutic drug monitoring (TDM) for psychotropic drugs offers the possibility to optimize psychiatric pharmacotherapy by tailoring the dosage of the administered drugs according to the characteristics of the individual patient. Thus, TDM may increase efficiency of therapy and reduce costs, and it makes a contribution to ensure patient safety. However, there is growing evidence that current use of TDM in routine psychiatric care is far from optimal so that its potential benefits can not fully come to fruition. Several studies have demonstrated a considerable amount of inappropriate TDM ordering, particularly blood sample taking too early after start of medication and change of dose, respectively, before steady state has been reached. Moreover, considerable discrepancies were apparent between the laboratory's recommendations and the actual clinical decision making on dose adjustments. In view of the potential benefits that TDM could have for medical and economic treatment outcome, there is the need for measures to improve its implementation in clinical routine. In addition to intensified physician education about the fundamental principles of drug pharmacokinetics, there are several possible strategies, which have turned out to be effective in other fields of medicine, including clinical pharmacokinetic services actively involved in the treatment process and use of computerized systems.