Implementation of Therapeutic Drug Monitoring and Pharmacogenetic Tests in Psychiatry: How About ABCB1?

Pharmacotherapy in psychiatry is characterised by a clinical response of patients frequently delayed by several days or even weeks. Moreover, there are no firm biological parameters which can be monitored to get an objective picture of the clinical outcome in patients suffering from schizophrenia or an affective disorder, except for some adverse effects. Therapeutic drug effects are often subtle, changes in psychopathology have to be measured using adequate rating scales. Such scales are also used for the qualitative and quantitative analysis of adverse effects such as sedation, inner tension, anxiety, suicidal ideas, extrapyramidal symptoms. On the other hand, laboratory exams have to be included to monitor possible adverse effects at e.g. the haematological level [1,2]. Besides, patients often lack adherence to the treatment. This situation but also environmental, personal and genetic factors are responsible for a high interindividual variability of the metabolism and pharmacokinetics in the subjects. This variability has consequences on the pharmacodynamics of the therapeutic agents. Therefore, therapeutic drug monitoring and pharmacogenetics tests have been introduced as valid instruments to optimise treatment [3].