Introduction The application of therapeutic drug monitoring (TDM), i. e. the quantification of
drug levels in a human matrix, can be helpful in numerous challenging clinical scenarios,
such as lack of therapeutic response, relapse, or adverse drug reactions (ADRs) related
to antipsychotic treatment.
Methods A selective review of invariably observational studies and case reports that highlight
the value of TDM as clinical routine tool for clinicians prescribing antipsychotic
medications.
Results Increasing literature demonstrates the usefulness of TDM in the appropriate dose
selection for antipsychotics. Specific patient subgroups treated with antipsychotics,
such as elderly, patients receiving polypharmacy, women under oral contraception and
pregnant women may essentially benefit from the regular use of TDM. Moreover, TDM can
be instrumental in the prevention of ADRs, with strength of evidence highly depending
on data availability. For example, a dominant amount of evidence is available for
clozapine compared to other antipsychotics. On the other hand, TDM evidence is practically
absent for clinical scenarios such as transition between different formulations of
antipsychotics, which have been less investigated, particularly for second-generation
antipsychotics.
Conclusions TDM can be useful for: 1) monitoring drug compliance, 2) evolution of the relationship
between the drug blood concentration and antipsychotic effect, 3) potential drug-interaction
susceptibility and ultimately for identification of the therapeutic window for clinical
efficacy of antipsychotic agents. The presentation will provide examples of condensed
clinical decision-making scenarios to assist clinicians who routinely prescribe antipsychotics,
to successfully apply TDM in routine clinical practice in order to optimize antipsychotic
efficacy and safety.
