A Real-World Study of Risk Factors for QTc Prolongation in Schizophrenia Patients Receiving Atypical Antipsychotics

Risk Stratification of QTc Prolongation in Critically Ill Patients Receiving Antipsychotics for the Management of Delirium Symptoms

BACKGROUND

Patients experiencing significant agitation or perceptual disturbances related to delirium in an intensive care setting may benefit from short-term treatment with an antipsychotic medication. Some antipsychotic medications may prolong the QTc interval, which increases the risk of potentially fatal ventricular arrhythmias. In this targeted review, we describe the evidence regarding the relationships between antipsychotic medications and QTc prolongation and practical methods for monitoring the QTc interval and mitigating arrhythmia risk.

METHODS

Searches of PubMed and Cochrane Library were performed to identify studies, published before February 2023, investigating the relationships between antipsychotic medications and QTc prolongation or arrhythmias.

RESULTS

Most antipsychotic medications commonly used for the management of delirium symptoms (eg, intravenous haloperidol, olanzapine, quetiapine) cause a moderate degree of QTc prolongation. Among other antipsychotics, those most likely to cause QTc prolongation are iloperidone and ziprasidone, while aripiprazole and lurasidone appear to have minimal risk for QTc prolongation. Genetic vulnerabilities, female sex, older age, pre-existing cardiovascular disease, electrolyte abnormalities, and non-psychiatric medications also increase the risk of QTc prolongation. For individuals at risk of QTc prolongation, it is essential to measure the QTc interval accurately and consistently and consider medication adjustments if needed.

CONCLUSIONS

Antipsychotic medications are one of many risk factors for QTc prolongation. When managing agitation related to delirium, it is imperative to assess an individual patient's risk for QTc prolongation and to choose a medication and monitoring strategy commensurate to the risks. In intensive care settings, we recommend regular ECG monitoring, using a linear regression formula to correct for heart rate. If substantial QTc prolongation (eg, QTc > 500 msec) is present, a change in pharmacologic treatment can be considered, though a particular medication may still be warranted if the risks of discontinuation (eg, extreme agitation, removal of invasive monitoring devices) outweigh the risks of arrhythmias.

AIMS

This review aims to summarize the current literature on relationships between antipsychotic medications and QTc prolongation and to make practical clinical recommendations towards the approach of antipsychotic medication use for the management of delirium-related agitation and perceptual disturbances in intensive care settings.

QTc prolongation in patients with schizophrenia taking antipsychotics: Prevalence and risk factors

BACKGROUND

QTc prolongation is one of the possible complications in patients with schizophrenia taking antipsychotics, which leads to malignant cardiac arrhythmia. No meta-analysis has been reported assessing the prevalence and correlated risk factors for QTc prolongation.

METHODS

This meta-analysis aimed to assess the evidence for the prevalence of QTc prolongation and correlated risk factors in patients with schizophrenia taking antipsychotics. Web of Science and PubMed were searched according to preset strategy. The quality of research was assessed by the Newcastle-Ottawa Scale (NOS).

RESULTS

In all, 15 studies covering 15,540 patients with schizophrenia taking antipsychotics were included. Meta-analysis showed that the prevalence of QTc prolongation in patients with schizophrenia taking antipsychotics was about 4.0% (95% confidence interval (CI): 3.0%-5.0%, p < 0.001). The prevalence was about 4.0% in Asia (95%CI: 3.0%-6.0%, p < 0.001), about 5.0% in Europe (95%CI: 2.0%-7.0%, p < 0.001), and about 2.0% in America (95%CI: 1.0%-3.0%, p < 0.001). Sensitivity analyses indicated the robustness of the result. Publication bias analysis reported a certain publication bias (t = 3.37, p = 0.012). Meta-regression suggested that female and elderly patients were clinically associated with a higher prevalence of QTc prolongation. According to included studies, smoking, comorbidity of cardiovascular disease, and abnormal levels of high-density lipoprotein/low-density lipoprotein might be related to QTc prolongation in patients with schizophrenia taking antipsychotics.

CONCLUSIONS

The prevalence of QTc prolongation in patients with schizophrenia taking antipsychotics was about 4.0%. Female and elderly patients were more likely to experience QTc prolongation. Close electrocardiogram monitoring was suggested in these at-risk populations.

Association Between Abnormal Metabolic Parameters and Receiving Subsequent Interventions in Children and Adolescents Initiating Second-Generation Antipsychotics

Objectives: This study aimed to examine the association between abnormal readings of metabolic parameters detected during second-generation antipsychotic (SGA) treatment and the likelihood of receiving subsequent adverse drug event interventions. Methods: This was a nested case-control study conducted on patients 1-17 years of age with at least two prescriptions of SGAs between January 2010 and January 2019 using TriNetX EMR data. Following an incident density sampling procedure, patients who received the SGA metabolic adverse event intervention (mAEI) (case) were matched with three nonrecipients (controls). The abnormal readings of metabolic parameters within 30 days before the initiation of mAIEs were further identified. These metabolic parameters include body mass index (BMI) and laboratory parameters such as cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, blood glucose, HbA1c, thyroid hormones, liver enzymes, and prolactin. The association of abnormal metabolic parameters with subsequent mAEIs was assessed using a conditional logistic regression model, after adjusting for demographic and other clinical risk factors. Results: One thousand eight hundred eighty-four children and adolescents met the inclusion criteria and were prescribed SGA mAEIs. The most common types of mAEIs prescribed were weight management pharmacotherapy (40.6%), switching from a high or medium metabolic risk profile SGA to a low-risk one (30.9%), nonpharmacological treatment (25.4%), and switching from SGA polytherapy to monotherapy (11.7%). The conditional logistic regression analysis on matched mAEI recipients and nonrecipients showed that patients with an abnormal BMI had 43% higher odds of receiving mAEI (odds ratio [95% confidence interval]: 1.43 [1.13-1.79]). However, the presence of an abnormal laboratory reading was not associated with the initiation of mAEIs. Conclusions: The prescribing of mAEIs were associated with the presence of obesity, but not with abnormal readings of other metabolic parameters, suggesting that additional data are needed to clarify the long-term implication of SGA metabolic adverse events other than weight gain and to inform the appropriate timing for interventions.