Bioanalytical methods for the determination of antipsychotics and metabolites in biological samples

Mental disorders, and particularly schizophrenia, are a serious cause of disability worldwide. Antipsychotic drugs are the first line of treatment for this disorder and are usually given at low doses due to their potency and high metabolism rate. Despite this, side effects are commonly associated with higher doses, requiring a careful monitoring to prevent overdose, while low doses are related to subtherapeutic effects. Therapeutic drug monitoring (TDM) is of outmost importance to determine patient compliance and improve the efficacy and safety of antipsychotics. Therefore, the development of accurate and sensitive methods for the determination of these drugs in conventional biological specimens is crucial. Additionally, in recent years, several alternative biological specimens raised the possibility of a simpler and faster monitoring. These are different matrices when compared to the commonly adopted plasma for TDM purposes. For this reason, several challenges may appear for sample preparation, and new techniques have been explored. This chapter will provide a comprehensive and critical review of the different biological specimens to monitor these drugs, but also the analytical methods and sample preparation techniques used for their determination in order to help physicians, researchers and other professionals working in the field.