Novel pharmaceutical treatment approaches for schizophrenia: a systematic literature review

Abstract

Purpose: Schizophrenia is a chronic and debilitating neuropsychiatric disorder affecting approximately 1% of the global population. Traditional antipsychotic treatments, while effective for positive symptoms, often have significant side effects and fail to address cognitive and negative symptoms. Novel pharmacological treatments targeting muscarinic receptors, TAAR1 agonists, serotonergic pathways, and glutamate modulation have emerged as promising alternatives.

Aim: This systematic literature review aims to critically evaluate the efficacy, safety, and mechanisms of action of novel pharmacological agents in the treatment of schizophrenia.

Methods: A comprehensive search was conducted across PubMed, Embase, Cochrane Library, Scopus, and Web of Science for randomized controlled trials (RCTs) and clinical trials published between April 2014 and March 2024. Studies evaluating novel treatments targeting muscarinic receptors, TAAR1 agonists, serotonergic agents, and glutamate modulation were included. Primary outcomes focused on symptom reduction and quality of life, while secondary outcomes included cognitive function and adverse events. The Joanna Briggs Institute (JBI) tool was used for quality assessment.

Results: Eleven studies involving 4614 participants (mean age 37-43 years, predominantly male) were included. Drugs evaluated included xanomeline-trospium (KarXT), pimavanserin, ulotaront, emraclidine, and bitopertin. Significant improvements in PANSS and CGI-S scores were observed, with xanomeline-trospium showing a mean reduction of 17.4 points (p < 0.001). Adverse events were mostly mild and transient, with nausea, constipation, and somnolence being common.

Conclusion: Novel treatments for schizophrenia show promise in managing both positive and negative symptoms, with generally favorable safety profiles. Future studies should focus on large-scale, long-term trials to refine their efficacy, safety, and clinical applicability.

Keywords: Antipsychotic medications; Cognitive and negative symptoms; Muscarinic receptor agonists; Novel pharmacological agents; Schizophrenia treatment; Systematic review; TAAR1 agonists.