Combination antipsychotics therapy for schizophrenia and related psychotic disorders interventions: Emergence to nanotechnology and herbal drugs

Abstract Combinational drug therapy is becoming more popular nowadays for the treatment of various diseases like Schizophrenia, depression, cancer, multi-drug resistance, etc. The increasing demand is due to their synergistic drug effects; improved drug therapeutic efficacy, and reduced drug toxicity. Schizophrenia is accounted as a pernicious mental disorder that affects approximately 1% population worldwide. Antipsychotics are the first-line treatment for the management of symptoms in schizophrenic patients. In most western countries people undergoing schizophrenia treatment do not respond to antipsychotics monotherapy (treatment-resistant people) also called “pharmacoresistant or refractory schizophrenia”. Currently, clozapine is the only medication that is approved by the USFDA for the treatment of refractory schizophrenia. But the patients who do not respond to clozapine or where the clozapine therapy fails to treat the patients suffering from refractory schizophrenia, a combination of antipsychotics are used. The combination of antipsychotics with herbal drugs has also been studied to improve the prognostic factor. Further, conventional delivery of combinational antipsychotics poses several limitations e.g. undesirable therapeutic effect, drug-related toxicity, adverse drug effects, and difficulty in crossing the blood-brain barrier, etc. So, the delivery of combinational antipsychotics via nanocarriers based systems like polymeric nanoparticles, solid lipid nanoparticles, nanostructure lipid carriers, liposomes, and polymeric micelles are exploited to deliver them at their targeted site by overcoming biological, biophysical, and biomedical barriers. The current review summarizes the combination of antipsychotics with other antipsychotics and herbal drugs and their delivery to the brain using nanocarriers for the management of schizophrenia and related disorders.