Insulin and glucose metabolism with olanzapine and a combination of olanzapine and samidorphan: exploratory phase 1 results in healthy volunteers

Allyl isothiocyanate, a TRPA1 agonist, protects against olanzapine-induced hypothalamic and hepatic metabolic aberrations in female mice

Olanzapine, a widely prescribed atypical antipsychotic, poses a great risk to the patient's health by fabricating a plethora of severe metabolic and cardiovascular adverse effects eventually reducing life expectancy and patient compliance. Its heterogenous receptor binding profile has made it difficult to point out a specific cause or treatment for the related side effects. Growing body of evidence suggest that transient receptor potential (TRP) channel subfamily Ankyrin 1 (TRPA1) has pivotal role in pathogenesis of type 2 diabetes and obesity. With this background, we aimed to investigate the role of pharmacological manipulations of TRPA1 channels in antipsychotic (olanzapine)-induced metabolic alterations in female mice using allyl isothiocyanate (AITC) and HC-030031 (TRPA1 agonist and antagonist, respectively). It was found that after 6 weeks of treatment, AITC prevented olanzapine-induced alterations in body weight and adiposity; serum, and liver inflammatory markers; glucose and lipid metabolism; and hypothalamic appetite regulation, nutrient sensing, inflammatory and TRPA1 channel signaling regulating genes. Furthermore, several of these effects were absent in the presence of HC-030031 (TRPA1 antagonist) indicating protective role of TRPA1 agonism in attenuating olanzapine-induced metabolic alterations. Supplementary in-depth studies are required to study TRPA1 channel effect on other aspects of olanzapine-induced metabolic alterations.

Olanzapine-Samidorphan for Schizophrenia: A Systematic Review and Meta-Analysis

Background and Objective

United States Food and Drug Administration (USFDA) recently approved a novel combination of olanzapine-samidorphan (OLZSAM) for managing olanzapine-associated adverse events (weight gain) in adult patients with schizophrenia and bipolar disorder. To opine about the safety and efficacy of OLZSAM, authors performed a systematic review and meta-analysis to convene justifiable evidence.

Methods

A thorough literature search was performed through the databases Embase, Cochrane Library, PubMed, and clinicaltrials.gov, from inception to September 2022, with the keywords: 'olanzapine and samidorphan' and schizophrenia; and "ALKS3831" and "lybalvi." Clinical trials published in English that analyzed the efficacy and safety of OLZSAM were included. The significant outcomes included in this study were change from baseline (CFB) in Positive and Negative Syndrome Scale (PANSS) at the end of the study, the proportion of patients with weight gain at the end of the study, the proportion of patients with at least one adverse event, and the incidence of drug discontinuation due to adverse events.

Results

The change in PANSS score at the end of the study was comparable among groups receiving OLZSAM and olanzapine alone: standardized mean difference (SMD) = 0.04; 95% CI = -0.09 to 0.17; p = 0.57. The OLZSAM group reported less incidence of weight gain: risk ratio (RR) = 0.91; 95% CI = 0.62-1.34; p = 0.63, and any adverse event: RR = 0.99; 95% CI = 0.90-1.09; p = 0.81. Drug discontinuation incidence was higher in the OLZSAM group: RR = 1.22; 95% CI = 0.84-1.79; p = 0.30.

Conclusions

The combination OLZSAM showed comparable efficacy to olanzapine alone in schizophrenia patients, with relatively less incidence of weight gain and adverse events; however, the drug discontinuation due to adverse events was more in the OLZSAM group.

Combining samidorphan with olanzapine to mitigate weight gain as a side effect in schizophrenia treatment

Purpose

This article analyzes clinical trials that provide evidence for the positive effects of using samidorphan to mitigate undesirable weight gain in patients diagnosed with schizophrenia who are undergoing treatment with olanzapine.

Views

Weight gain is a prevalent and problematic side effect of antipsychotic drug therapy, particularly in patients with schizophrenia. To address this issue, extensive research is being conducted to explore new drug therapies that can effectively counteract psychotic symptoms while minimizing the occurrence of unwanted side effects. One promising approach involves the addition of weight-loss substances to existing medications. Studies have indicated that opioid receptor antagonists, such as samidorphan, have the potential to facilitate weight loss. Consequently, a novel therapy combining samidorphan and olanzapine has been developed and is discussed in detail in this article.

Conclusions

The combination of samidorphan and olanzapine has demonstrated its ability to effectively reduce weight gain in patients with schizophrenia, without compromising the drug's primary function of alleviating psychotic symptoms. Moreover, the inclusion of samidorphan in the treatment regimen may contribute to a lower risk of cardiovascular events, though it is worth noting that it could also lead to an increase in digestive side effects. Despite this potential drawback, the introduction of this innovative therapy represents a significant advancement in the management of obesity among individuals with schizophrenia.

Relapse in patients with schizophrenia and amisulpride-induced hyperprolactinemia or olanzapine-induced metabolic disturbance after switching to other antipsychotics

Hyperprolactinemia and metabolic disturbance are common side effects of antipsychotics that cause intolerance. Despite its potential influence on relapse, there are no established guidelines for antipsychotic switching. This naturalistic study explored the association between antipsychotic switching, baseline clinical status, metabolic changes, and relapse in patients with schizophrenia. In total, 177 patients with amisulpride-induced hyperprolactinemia and 274 with olanzapine-induced metabolic disturbance were enrolled. Relapse was determined by assessing changes in Positive and Negative Syndrome Scale (PANSS) total scores from baseline to 6 months (increased over 20% or 10% reaching 70). Metabolic indices were measured at baseline and 3 months. Patients with baseline PANSS >60 were more likely to relapse. Further, patients switching to aripiprazole had a higher risk of relapse regardless of their original medication. Participants who originally used amisulpride had reduced prolactin levels following medication change, while switching to olanzapine caused increased weight and blood glucose levels. In patients originally using olanzapine, only switching to aripiprazole reduced insulin resistance. Adverse effects on weight and lipid metabolism were observed in patients who switched to risperidone, while amisulpride improved lipid profiles. Changing schizophrenia treatment requires careful consideration of multiple variables, particularly the choice of substituted drug and the patient's baseline symptoms.

Reduction in Multiple Cardiometabolic Risk Factors With Combined Olanzapine/Samidorphan Compared With Olanzapine: Post Hoc Analyses From a 24-Week Phase 3 Study

BACKGROUND AND HYPOTHESES

Weight gain and adverse cardiometabolic effects often limit the clinical utility of olanzapine. In ENLIGHTEN-2, combining olanzapine with the opioid receptor antagonist samidorphan (OLZ/SAM) mitigated olanzapine-associated weight gain. These analyses tested the hypothesis that OLZ/SAM would be associated with reduced adverse cardiometabolic effects compared with olanzapine.

STUDY DESIGN

This phase 3 double-blind study randomized adults with schizophrenia to OLZ/SAM or olanzapine for 24 weeks. Post hoc analyses assessed changes from baseline to week 24 in cardiometabolic risk parameters, including body mass index (BMI), risk of developing obesity (BMI ≥30 kg/m2) or metabolic syndrome, waist circumference, along with mean and potentially clinically significant changes in blood pressure, glucose, and lipids.

RESULTS

After 24 weeks' treatment, compared with olanzapine, OLZ/SAM was associated with smaller least-squares mean (LSM) changes from baseline in systolic blood pressure (LSM difference, -2.63 mm Hg; 95% CI: -4.78, -0.47), diastolic blood pressure (LSM difference, -0.75 mm Hg; 95% CI: -2.31, 0.80), and BMI (LSM difference, -0.65 kg/m2; 95% CI: -1.01, -0.28). OLZ/SAM treatment was also associated with reduced risk of shifting from normal blood pressure to stage 1/2 hypertension (odds ratio [OR], 0.48; 95% CI: 0.24, 0.96), becoming obese (OR, 0.52; 95% CI: 0.32, 0.82), and developing metabolic syndrome (OR, 0.55; 95% CI: 0.31, 0.99) compared with olanzapine. No treatment group differences were noted for risk of hyperglycemia or hyperlipidemia.

CONCLUSIONS

OLZ/SAM treatment was associated with lower risk of worsening cardiometabolic risk factors related to obesity, hypertension, and metabolic syndrome relative to olanzapine. NCT02694328, https://clinicaltrials.gov/ct2/show/NCT02694328.