Therapeutic drug monitoring of atypical antipsychotics

The paper presents an overview and analysis of the results of research on therapeutic ranges of concentrations and receptor occupancy, mainly D2 receptors, in the treatment with some atypical antipsychotic drugs. Amisulpride, aripiprazole, clozapine, quetiapine, olanzapine, risperidone, paliperidone, sertindole, and ziprasidone were taken into account. The benefits of therapeutic drug monitoring to optimize the effectiveness of treatment and avoid side effects or toxicity were shown. The safety of patients, with the possibility to use the lowest effective dose, is an undoubted profit of TDM. This helps to avoid overdosing resulting in adverse events (with particular emphasis on extrapyramidal symptoms and seizures). The need and desirability of TDM is due to the inter -and intraindividual differences in the pharmacokinetics of drugs, because only some of them have a close correlation between dose and plasma concentration. The plasma concentration correlates well with the occupancy of D2 receptors. The efficient and safe level is determined at 60-80%. Based on the knowledge of the indications for TDM and therapeutic concentration ranges, amisulpride, clozapine and olanzapine have the highest level of recommendation to use TDM. Therapeutic ranges of plasma concentrations of the analyzed drugs were determined to be 200-320 ng/ml for amisulpride, 150-210 ng/ml for aripiprazole, over 350-500 ng/ml for clozapine, 50-500 ng/ml for quetiapine, 20-40 ng/ml for olanzapine, 20-60 ng/ml for risperidone and paliperidone, 50-100 ng/ml for sertindole and 50-130 ng/ml for ziprasidone.