Comparative cardiovascular safety of risperidone and olanzapine, based on electrocardiographic parameters and blood pressure: a prospective open label observational study

Olanzapine Pharmacokinetics: A Clinical Review of Current Insights and Remaining Questions

Olanzapine is one of the most widely used antipsychotics since its initial approval by the US Food and Drug Administration in 1996 and has undergone extensive pharmacokinetic study. Despite being utilized in clinical psychiatry for decades, there remain questions regarding the variety of available formulations, the utility of therapeutic drug monitoring, altered kinetic properties in special populations/medical illnesses, the use of high-dose olanzapine, and drug interactions, among many others. We performed a narrative literature review of olanzapine pharmacokinetics in June 2023 using the US National Library of Medicine's PubMed.gov resource (https://www.ncbi.nlm.nih.gov/pubmed) and Google Scholar. Herein, we review clinically relevant aspects of olanzapine pharmacokinetic data while highlighting knowledge gaps and potential areas of future study.

Olanzapine-associated dose-dependent alterations for weight and metabolic parameters in a prospective cohort

Metabolic abnormalities have been associated with olanzapine treatment. We assessed if olanzapine has dose‐dependent effects on metabolic parameters with changes for weight, blood pressure, lipid and glucose profiles being modelled using linear mixed‐effects models. The risk of metabolic abnormalities including early weight gain (EWG) (≥5% during first month) was assessed using mixed‐effects logistic regression models. In 392 olanzapine‐treated patients (median age 38.0 years, interquartile range [IQR] = 26.0–53.3, median dose 10.0 mg/day, IQR = 5.0–10.0 for a median follow‐up duration of 40.0 days, IQR = 20.7–112.2), weight gain was not associated with olanzapine dose (p = 0.61) although it was larger for doses versus ≤10 mg/day (2.54 ± 5.55 vs. 1.61 ± 4.51% respectively, p = 0.01). Treatment duration and co‐prescription of >2 antipsychotics, antidepressants, benzodiazepines and/or antihypertensive agents were associated with larger weight gain (p < 0.05). Lower doses were associated with increase in total and HDL cholesterol and systolic and diastolic blood pressure (p < 0.05), whereas higher doses were associated with glucose increases (p = 0.01). Patients receiving >10 mg/day were at higher EWG risk (odds risk: 2.15, 1.57–2.97). EWG might be prominent in high‐dose olanzapine‐treated patients with treatment duration and co‐prescription of other medications being weight gain moderators. The lack of major dose‐dependent patterns for weight gain emphasizes that olanzapine‐treated patients are at weight gain risk regardless of the dose.

The effect of risperidone and electroconvulsive therapy on corrected QT interval in electrocardiogram of psychiatric patients

BACKGROUND

Some types of antidepressants and antipsychotic medications have cardiovascular side effects that can be life-threatening. Electroconvulsive therapy (ECT) is capable of generating physiological stress and may lead to increased QT interval followed by arrhythmias. Risperidone can also increase the risk of arrhythmia by increasing the corrected QT (QTc) interval. Since many patients require co-administration of risperidone and ECT, this study aimed to investigate the concurrent effect of ECT and risperidone administration on the QTc interval.

METHODS

For this cross-sectional study, 60 patients (18-65 years) admitted in 22 Bahman Psychiatric Hospital (Qazvin, Iran) that were candidate for treatment with risperidone, ECT, or both methods were concurrently divided into three groups. The groups included patients treated with ECT, risperidone, and combination treatment (risperidone and ECT). At the beginning of the study, electrocardiogram (ECG) was obtained for all patients and QT was performed manually, and finally, QTc interval was measured two times for each group. Required information was collected through medical records. Then, inferential statistics, analysis of variance (ANOVA), was used to determine differences between different variables.

RESULTS

A significant increase in heart rate (HR) in the third group compared to first and second groups was observed. None of the treatments had a significant effect on QTc interval, but the QTc interval increased slightly in groups treated with the ECT alone and particularly, the ECT plus risperidone in comparison to the baseline values.

CONCLUSION

Our study showed that risperidone, ECT, and their concomitant combination did not affect the QTc interval. Therefore, risperidone and ECT are safe and their combination can also be a good option for refractory patients undergoing ECG monitoring and cardiopulmonary devices.

Second-Generation Antipsychotic Drugs for Patients with Schizophrenia: Systematic Literature Review and Meta-analysis of Metabolic and Cardiovascular Side Effects

BACKGROUND AND OBJECTIVES

Second-generation antipsychotics (SGAs) for schizophrenia show different risk profiles, whose evidence has been evaluated through comparative reviews on randomized controlled trials (RCTs) and observational studies.

METHODS

We performed a systematic review and meta-analysis of weight gains, metabolic and cardiovascular side effects of SGAs, relying on both RCTs and observational studies, by comparing variations between the start of treatment and the end of follow-up. The systematic review refers to papers published from June 2009 to November 2020. PRISMA criteria were followed. No restrictions on heterogeneity level have been considered for meta-analysis. A test for the summary effect measure and heterogeneity (I2 metric) was used.

RESULTS

Seventy-nine papers were selected from 3076 studies (61% RCTs, 39% observational studies). Olanzapine and risperidone reported the greatest weight gain and olanzapine the largest BMI increase. Paliperidone showed the highest increase in total cholesterol, but is the only drug reporting an increase in the HDL cholesterol. Quetiapine XR showed the highest decrease in fasting glucose. Lurasidone showed the lowest increase in body weight and a reduction in BMI and was also the only treatment reporting a decrease in total cholesterol and triglycerides. The highest increase in systolic and diastolic blood pressure was reported by quetiapine XR.

CONCLUSIONS

Despite some limitations (differences in the mean dosages per patient and other side effects not included) this paper provides the first complete meta-analysis on SGAs in variations on metabolic risk profile between start of treatment and end of follow-up, with useful results for clinical practice and possibly for future economic evaluation studies.

Clinical, physical, physiological, and cardiovascular risk patterns of adults with schizophrenia: CORTEX-SP study: Characterization of adults with schizophrenia

Schizophrenia (SP) is a severe mental illness with high rates of premature morbidity and mortality, associated with an unhealthy lifestyle and the side effects of drug treatment. The aims of the study were: 1) to determine some key physical, physiological and biochemical markers of health status, including sleep quality, in adults (42±10 yr) with SP (n=126), 2) to estimate cardiovascular risk (CVR), and 3) to compare all studied variables with a healthy control (HC) population (n=30). Assessment was based on body composition, blood pressure, cardiorespiratory condition, sleep quality with triaxial accelerometry for eight days and biochemical analysis. Participants with SP showed a cardiovascular risk profile including "overweight metabolically abnormal", low cardiorespiratory fitness, and impairment of ventilatory efficiency. Although individuals with SP slept more compared to HC, similar sleep efficiency was shown by both groups, but with significantly higher levels of wake after sleep onset by SP. The assessment of CVR revealed significantly higher values in SP (moderate risk) compared to HC (low risk) regardless of the estimation system. The identification of specific clinical, physical, and physiological CVR profiles in SP illness compared to healthy people strongly suggests targeting a comprehensive approach including non-pharmacological interventions. Clinical Trials.gov identifier, NCT03509597. Date of registration: April 26^th, 2018.

The use of melatonin to mitigate the adverse metabolic side effects of antipsychotics

Antipsychotic drugs are efficacious first-line treatments for many individuals diagnosed with a psychiatric illness. However, their adverse metabolic side-effect profile, which resembles the metabolic syndrome, represents a significant clinical problem that increases morbidity and limits treatment adherence. Moreover, the mechanisms involved in antipsychotic-induced adverse metabolic effects (AMEs) are unknown and mitigating strategies and interventions are limited. However, recent clinical trials show that nightly administration of exogenous melatonin may mitigate or even prevent antipsychotic-induced AMEs. This clinical evidence in combination with recent preclinical data implicate the circadian system in antipsychotic-induced AMEs and their mitigation. In this chapter, we provide an overview on the circadian system and its involvement in antipsychotic-induced AMEs, as well as the potential beneficial effect of nightly melatonin administration to mitigate them.

Overexpression of Insig-2 inhibits atypical antipsychotic-induced adipogenic differentiation and lipid biosynthesis in adipose-derived stem cells

Atypical antipsychotics (AAPs) are considered to possess superior efficacy for treating both the positive and negative symptoms of schizophrenia; however, AAP use often causes excessive weight gain and metabolic abnormalities. Recently, several reports have demonstrated that AAPs activate sterol regulatory element-binding protein (SREBP). SREBP, SREBP cleavage-activating protein (SCAP) and insulin-induced gene (Insig) regulate downstream cholesterol and fatty acid biosynthesis. In this study, we explored the effects of clozapine, olanzapine and risperidone on SREBP signaling and downstream lipid biosynthesis genes in the early events of adipogenic differentiation in adipose-derived stem cells (ASCs). After the induction of adipogenic differentiation for 2 days, all AAPs, notably clozapine treatment for 3 and 7 days, enhanced the expression of SREBP-1 and its downstream lipid biosynthesis genes without dexamethasone and insulin supplementation. Simultaneously, protein level of SREBP-1 was significantly enhanced via inhibition of Insig-2 expression. By contrast, SREBP-1 activation was suppressed when Insig-2 expression was upregulated by transfection with Insig-2 plasmid DNA. In summary, our results indicate that AAP treatment, notably clozapine treatment, induces early-stage lipid biosynthesis in ASCs. Such abnormal lipogenesis can be reversed when Insig-2 expression was increased, suggesting that Insig/SCAP/SREBP signaling may be a therapeutic target for AAP-induced weight gain and metabolic abnormalities.

Olanzapine-induced early cardiovascular effects are mediated by the biological clock and prevented by melatonin

Second generation antipsychotics (SGA) are associated with adverse cardiometabolic side effects contributing to premature mortality in patients. While mechanisms mediating these cardiometabolic side effects remain poorly understood, three independent studies recently demonstrated that melatonin was protective against cardiometabolic risk in SGA-treated patients. As one of the main target areas of circulating melatonin in the brain is the suprachiasmatic nucleus (SCN), we hypothesized that the SCN is involved in SGA-induced early cardiovascular effects in Wistar rats. We evaluated the acute effects of olanzapine and melatonin in the biological clock, paraventricular nucleus and autonomic nervous system using immunohistochemistry, invasive cardiovascular measurements, and Western blot. Olanzapine induced c-Fos immunoreactivity in the SCN followed by the paraventricular nucleus and dorsal motor nucleus of the vagus indicating a potent induction of parasympathetic tone. The involvement of a SCN-parasympathetic neuronal pathway after olanzapine administration was further documented using cholera toxin-B retrograde tracing and vasoactive intestinal peptide immunohistochemistry. Olanzapine-induced decrease in blood pressure and heart rate confirmed this. Melatonin abolished olanzapine-induced SCN c-Fos immunoreactivity, including the parasympathetic pathway and cardiovascular effects while brain areas associated with olanzapine beneficial effects including the striatum, ventral tegmental area, and nucleus accumbens remained activated. In the SCN, olanzapine phosphorylated the GSK-3β, a regulator of clock activity, which melatonin prevented. Bilateral lesions of the SCN prevented the effects of olanzapine on parasympathetic activity. Collectively, results demonstrate the SCN as a key region mediating the early effects of olanzapine on cardiovascular function and show melatonin has opposing and potentially protective effects warranting additional investigation.