Exploring hidden issues in the use of antipsychotic polypharmacy in the treatment of schizophrenia

The mainstay of schizophrenia treatment is pharmacological therapy using various antipsychotics including first- and second-generation antipsychotics which have different pharmacokinetic and pharmacodynamic property leading to differential presentation of adverse events (AEs) and treatment effects such as negative symptoms, cognitive symptoms and cormorbid symptoms. Major treatment guidelines suggest the use of antipsychotic monotherapy (APM) as a gold standard in the treatment of schizophrenia. However, the effects of APM is inadequate and less potent to achieve symptom remission as well as functional recovery in real practice which has been consistently reported in numerous controlled clinical trials, large practical trials, independent small studies and systematic reviews till today. Therefore antipsychotic polypharmacy (APP) regardless of the class of antipsychotics has been also commonly utilized for many reasons in real world practice. However, APP has also crucial pitfalls including increase of total psychotics including antipsychotics, high-doses of antipsychotics used, poor compliance, drug-drug interaction and risks for developing AEs, all of which are paradoxically related to poor clinical outcomes, whereas APP has also substantial advantages in reduction of re-hospitalization, severe psychopathology and targeted control of concurrent symptoms. Given currently limited therapeutic options, it is also important to properly utilize APP in order to maximize its clinical utility and minimize its risk for better treatment outcomes for patients with schizophrenia, based on risk/benefit with full understanding of pharmacological and clinical issues on APP. The present paper intends to address intriguing and important issues in the use of APP in real world practice.