Worth the Weight? Olanzapine Prescribing in Schizophrenia. A Review of Weight Gain and Other Cardiometabolic Side Effects of Olanzapine

A retrospective analysis of cardiovascular outcomes of clozapine treated individuals within Hunter New England

BACKGROUND

Clozapine has demonstrated superiority in improving both positive and negative symptoms of treatment-resistant schizophrenia; however, there are associated treatment-limiting side effects, including myocarditis, cardiomyopathy and agranulocytosis.

AIM

This retrospective cohort study describes the prevalence of myocarditis, left ventricular (LV) dysfunction, cardiovascular risk factors and outcomes in a cohort of patients maintained on clozapine therapy.

METHODS

Data were retrospectively collated from patients who had a diagnosis of schizophrenia, had been managed with clozapine at any stage during their care and undergone at least one echocardiogram.

RESULTS

Between March 2020 and September 2021 674 patients were identified, 71% were male, with a mean age of 47 years old (interquartile range (IQR) 40-57). The mean duration of clozapine use was 7 years (IQR 4-13). The overall mortality was 5.54% during the follow-up period. Myocarditis was identified in one patient (0.15%) within the first 30 days, and an additional five cases were identified over the follow-up period (0.89%). The combined incidence of heart failure (HF) and myocarditis was 1.6% during the follow-up period. There was no association between LV size and function at baseline or during follow-up and adverse cardiac outcomes (comprising death, myocarditis, HF). Older age at initiation of therapy and baseline E/e' ratio were associated with risk of HF and myocarditis.

CONCLUSION

The overall incidence of myocarditis and HF during follow-up was low, with surveillance echocardiography offering limited predictive value. Patients maintained on clozapine are at risk of significant cardiovascular sequelae, likely reflecting an adverse risk factor profile.

Investigating the effect of zeaxanthin on olanzapine-induced metabolic disorders in rats

Objective

Olanzapine (OLZ) is used by some patients with bipolar disorder and schizophrenia. Some of its side effects include weight gain and metabolic syndrome. Zeaxanthin (Zx), a yellow pigment found in egg yolk as well as some yellow and orange plants and fruits, is an anti-obesity factor that aids in the treatment of metabolic disorders. The effects of Zx on metabolic disorders caused by OLZ were investigated in this study.

Materials and Methods

Female Wistar rats were randomly divided into seven groups (n=6): 1. control (vehicle); 2. OLZ (5 mg/kg, 14 days, intraperitoneal (i.p.)); 3-5. OLZ + Zx (12.5, 25, and 50 mg/kg, 14 days, gavage); 6. OLZ+ metformin (100 mg/kg, 14 days, i.p.); and 7. Zx (50 mg/kg, 14 days). Weight changes were checked every 3 days and food intake was monitored every day. Systolic blood pressure, insulin, blood sugar, triglyceride, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and leptin levels were evaluated on the last day of the study.

Results

OLZ caused an increase in weight (84.5% increase on day 15), food intake, blood pressure, triglyceride, LDL, insulin, blood sugar, and leptin compared to the control group (p<0.01 and p<0.001). The use of different doses of Zx (12.5, 25, and 50 mg/kg) and metformin decreased weight (the percentages of weigh reduction on day 15 were 91.92% for Zx (50 mg/kg) and 59.39% for metformin), food intake, systolic blood pressure, triglyceride, LDL, insulin, blood sugar, and leptin compared to the OLZ group. The amounts of cholesterol and HDL were not different in different groups.

Conclusion

Zx alleviates metabolic abnormalities including hypertension, hyperglycemia, and dyslipidemia in rats.

Long-term second-generation antipsychotics decreases bone formation and resorption in male patients with schizophrenia

RATIONALE

Patients with schizophrenia with second-generation antipsychotics (SGAs) treatment have shown an increased risk of bone fragility and susceptibility to fracture; however, it is still unclear whether this risk is derived from the effect of antipsychotics on balance of bone metabolism.

OBJECTIVES

We investigated the changes of two bone turnover biomarkers (BTMs) concentrations in people with schizophrenia receiving SGAs: procollagen type I aminoterminal propeptide (PINP) and C-terminal telopeptide of type I collagen (CTX-1) as BTMs of osteogenesis and bone resorption, respectively, to explore how antipsychotics contribute to bone fragility.

METHODS

We recruited 59 Chinese male patients with schizophrenia (32 drug-naïve first-episode (DNFE) patients and 27 chronic patients) to undergo 8 weeks SGAs treatment. Fasting peripheral blood samples of pre- and posttreatment were collected, plasma levels of PINP and CTX-1 were measured.

RESULTS

The interaction effects of group and time on PINP and CTX-1 concentrations were found (P = .016 and P = .008). There was a significant decrease for both BTMs concentrations of the posttreatment compared to the pretreatment (P<.001 and P = .003). Chronic patients had significantly higher changes of BTMs concentrations compared to DNFE patients (P = .048 and P = .024). There was a positive correlation of the two BTMs of pretreatment with disease course in DNFE group (r = .37, P = .039;r = .38, P = .035) and a negative correlation of PINP of pretreatment with age in the chronic group (r=-.40, P = .039).

CONCLUSION

Long-term SGAs medication inhibited osteogenesis in a dose- and time-dependent manner and damaged the balance of bone formation and bone resorption.

Prevalence and Cost of Antipsychotic Prescribing, within the Context of Psycholeptic Prescribing, in the Irish Setting

Psycholeptic and specifically antipsychotic prescribing is increasing worldwide each year. This study aims to investigate the prevalence and cost of antipsychotic prescribing, within the wider frame of psycholeptic prescribing, in the Irish context. Quantitative analysis of a dataset from the Primary Care Reimbursement Service relating to cost and prescribing frequency of ATC Class N05 psycholeptic drugs from January 2020-August 2022 inclusive was conducted using Microsoft® Excel® for Microsoft 365 MSO (Version 2311) and STATA 18. Descriptive statistics and time-trend regression analysis were used to investigate the prescribing prevalence of psycholeptics and antipsychotics licensed for use in the Republic of Ireland, and the total cost per funding scheme. The prevalence of psycholeptic prescribing increased yearly from 2020-2022, peaking at 328,572 prescriptions in December 2020 with a total cost of psycholeptic drugs to the State in 2021 of €57,886,250, which was 0.5% of an increase on 2020. Over the 32-month time period, the average monthly cost of psycholeptic drugs was €4,436,469 on the General Medical Services (GMS) scheme and €369,154 on the Drug Payment Scheme (DPS). In 2021, quetiapine, olanzapine, and risperidone were the most prescribed antipsychotics, accounting for 66.58% of antipsychotics prescribed on the GMS scheme. This study identified the large expenditure on psycholeptics and antipsychotics in Ireland, with a higher proportion of the Irish healthcare budget spent on antipsychotics than that of the UK and the USA. The development of Irish antipsychotic prescribing guidelines may allow for structured, cost-effective prescribing.

Delayed-Onset olanzapine-induced rhabdomyolysis

Olanzapine is a commonly used and effective second-generation antipsychotic agent used for the control of paranoia and agitation in schizophrenia and bipolar disorder as well as in the behavioural and psychological symptoms of dementia. Serious side effects of treatment are uncommon but spontaneous rhabdomyolysis represents a rare complication. We describe here a patient treated with a stable dose of olanzapine for more than 8 years who developed acute severe rhabdomyolysis without an identifiable trigger and without features suggestive of neuroleptic malignant syndrome. The rhabdomyolysis was atypical in its delayed onset and severity with a creatine kinase level of 345 125 U/L, the highest level reported in the available literature. We also describe the clinical manifestations of delayed-onset olanzapine-induced rhabdomyolysis and its differentiation from neuroleptic malignancy syndrome, and we highlight key aspects of management to prevent or minimise further complications such as acute kidney injury.

Olanzapine-induced decreases of FGF21 in brown adipose tissue via histone modulations drive UCP1-dependent thermogenetic impairment

Long-term olanzapine treatment has been associated with serious metabolism disorders, such as abnormal body weight gain, hyperglycemia, and dyslipidemia. Recently, accumulated evidence points to a link between the metabolic disorders caused by olanzapine and thermogenetic impairment. Fibroblast growth factor 21 (FGF21), a pleiotropic protein, is a potent stimulator of thermogenesis in brown adipose tissue (BAT). However, the relationship between autocrine FGF21 in BAT and thermogenetic impairment induced by olanzapine has not been investigated. In this study, C57BL/6 mice and C3H10T1/2 (a brown adipocyte cell line) were used to investigate the role of FGF21 in modulating thermogenetic impairments caused by olanzapine. Our data found a fall in BAT temperature, with a decrease in the protein levels of uncoupling protein 1 (UCP1) and FGF21 in olanzapine-treatment mice. Olanzapine-induced deficits of mitochondrial activity and the expression of UCP1 and related thermogenetic factors could be improved by FGF21-overexpression in brown adipocytes. Furthermore, ChIP-sequencing showed the H3K9me3 modification in Fgf21 was dramatically increased in BAT of mice with olanzapine treatment. Lysine-specific demethylase 4a (KDM4a), a histone demethylase responsible for site-specific erasure of H3K9me3, was decreased in olanzapine-treated C3H10T1/2 cells, whereas FGF21 and UCP1 expression and thermogenesis were upregulated in KMD2a-overexpressing brown adipocyte. We concluded that FGF21 was a crucial regulator mediating UCP1-dependent thermogenetic impairments by olanzapine-modulating histone methylations. Our results also provide novel insights into identifying a new therapeutic target for treating metabolic side effects caused by the antipsychotic drug.