A single blind comparative clinical study of the effects of chlorpromazine and risperidone on positive and negative symptoms in patients of schizophrenia

Efficacy, safety, and tolerability of ulotaront (SEP-363856, a trace amine-associated receptor 1 agonist) for the treatment of schizophrenia and other mental disorders with similar pathophysiology: a systematic review of preclinical and clinical trials

INTRODUCTION

Schizophrenia is a mental illness that can disrupt emotions, perceptions, cognition, and reduce quality of life. The classical approach to treat schizophrenia uses typical and atypical antipsychotics; however, limitations include low efficacy in mitigating negative symptoms and cognitive dysfunctions, and a range of adverse effects. Evidence has accumulated on trace amine-associated receptor 1 (TAAR1) as a novel therapeutic target for treating schizophrenia. This systematic review investigates the available evidence on a TAAR1 agonist, ulotaront, as a treatment for schizophrenia.

METHODS

A systematic search was conducted on PubMed/MEDLINE, and Ovid databases for English-published articles from inception to December 18, 2022. Literature focusing on the association between ulotaront and schizophrenia were evaluated based on an inclusion/exclusion criterion. Selected studies were assessed for risk of bias, using Cochrane Collaboration tool, and summarized in a table to generate discussion topics.

RESULTS

Three clinical, two comparative, and five preclinical studies examining ulotaront's pharmacology, tolerability and safety, and/or efficacy were identified. Results indicate that ulotaront has a differing adverse effects profile from other antipsychotics, may mitigate metabolic-related adverse effects commonly associated with antipsychotics, and may be effective for treating positive and negative symptoms.

CONCLUSIONS

Findings from available literature present ulotaront as a potential and promising alternative treatment method for schizophrenia. Despite this, our results were limited due to lack of clinical trials on ulotaront's long-term efficacy and mechanisms of action. Future research should focus on these limitations to elucidate ulotaront's efficacy and safety for the treatment of schizophrenia and other mental disorders with similar pathophysiology.

Short term effectiveness of haloperidol versus risperidone in first-episode schizophrenia

Aim:

The supposed superiority of second-generation antipsychotic medication over first-generation antipsychotic medication has been challenged recently by several studies. This naturalistic retrospective study aims to compare outcomes between patients admitted for the first time with first-episode schizophrenia-spectrum disorders who were started on either haloperidol or risperidone. Would choice of antipsychotic affect length of admission and three-month outcome?

Methods:

Seventy-seven patients from the Early Psychosis Intervention Programme at the Institute of Mental Health were included in this study. Length of stay was obtained from hospital electronic records. Positive and Negative Syndrome Scale (PANSS) and Global Assessment of Functioning (GAF) scores at three months were used to assess severity of psychopathology and level of functioning respectively. A secondary analysis was also done to measure time to discontinuation for any reason.

Results:

There was a significant reduction in PANSS total, positive, negative and general psychopathology scores in both groups at three months, with the patients on risperidone showing a greater reduction in PANSS negative scores compared to the patients on haloperidol. However, there were no statistically significant differences between length of hospitalization and total PANSS score at three months between the two groups. Time to discontinuation was longer in the risperidone group compared to the haloperidol group.

Conclusion:

The findings of this study suggest that risperidone has a better effect on negative symptoms and is better tolerated, resulting in a longer time to discontinuation. Thus, starting a patient with first-episode schizophrenia-spectrum disorder on risperidone would result in a better short-term outcome as compared to starting the same patient on haloperidol.

Antipsychotic Trials in Schizophrenia from India: A Systematic Review and Meta-analysis

Ethnic and regional variations have been found in the pharmacological treatment response. Though many efficacy studies have been conducted in India for antipsychotic treatment modalities of schizophrenia, there is a lack meta-analytic data of the existing literature from India. This study aimed to conduct a systematic review and meta-analysis of the antipsychotic treatment trials of schizophrenia in the Indian context. All controlled trials from India evaluating the clinical efficacy of antipsychotics in patients with schizophrenia were evaluated and 28 trials were included in the metanalysis. Effect sizes were computed using Cohen's 'd' and risk of bias was evaluated. Meta analysis revealed superiority of first generation antipsychotics over placebo (mean effect size of 1.387, confidence interval of 1.127 to 1.648). Second generation antipsychotics were marginally better than first generation antipsychotics (effect size 0.106, confidence intervals 0.009 to 0.204). There was improvement in the methodology of the trials over time (Kendall tau=0.289, P=0.049), though no statistically significant increase in trial duration and sample size was noted. There is lack of data on long term efficacy of antipsychotic in schizophrenia from India. First generation antipsychotics have demonstrated benefits over placebo in patients with schizophrenia in the Indian context, though marginally lesser than second generation ones.

Risperidone-associated adverse drug reactions and CYP2D6 polymorphisms in a South African cohort

Background

Contradictory information exists regarding the influence of CYP2D6 polymorphisms on adverse drug reactions (ADRs) (extrapyramidal symptoms (EPS) and weight gain) related to risperidone treatment. This prompted us to evaluate the influence of CYP2D6 genetic variation in a cohort of South African patients who presented with marked movement disorders and/or weight gain while on risperidone treatment.

Methods

Patients who were experiencing marked risperidone ADRs were recruited from Weskoppies Public Psychiatric Hospital. As poor or intermediate metabolism was expected, comprehensive CYP2D6 sequence variations were evaluated using XL-PCR + Sequencing.

Results

No statistically significant association was found between CYP2D6 poor metabolism and risperidone ADRs. An inverse relationship between EPS and weight gain was however identified. A novel CYP2D6 allele was identified which is unlikely to affect metabolism based on in silico evaluation.

Conclusion

CYP2D6 variation appeared not to be a good pharmacogenetic marker for predicting risperidone-related ADRs in this naturalistic South African cohort. Evaluation of a larger cohort would be needed to confirm these observations, including an examination of the role of potential intermediaries between the hypothesised genetic and clinical phenotypes.