Risk management of QTc-prolongation in patients receiving haloperidol: an epidemiological study in a University hospital in Belgium

Incidences, risk factors, and clinical correlates of severe QT prolongation after the use of quetiapine or haloperidol

BACKGROUND

Case reports suggest that quetiapine or haloperidol use is associated with severe QT prolongation (SQTP) and torsades de pointes.

OBJECTIVE

The purpose of this study was to examine the incidences, risk factors, and outcomes of SQTP in quetiapine and haloperidol users.

METHODS

This study accessed electronic medical records from a multicenter health-care hospital system in Taiwan and included patients who received quetiapine or haloperidol therapy and had both baseline and follow-up electrocardiograms. SQTP was defined as a posttreatment corrected QT (QTc) interval exceeding 500 ms or an increase in QTc interval of >60 ms compared with the baseline value. We analyzed the risk factors and outcomes of SQTP using multivariate logistic regression.

RESULTS

Mean increases in QTc interval were +8.3 ± 51.8 and +8.9 ± 44.0 ms after the administration of quetiapine (n = 8832) and haloperidol (n = 2341). Among these users, 1149 (13.0%) and 333 (14.2%) developed SQTP, respectively. Common risk factors for SQTP included old age, heart failure, hypokalemia, amiodarone use, and baseline QTc interval. SQTP in quetiapine users was significantly associated with ventricular arrhythmias (odds ratio 2.84; 95% confidence interval 1.95-4.13) and sudden cardiac death (odds ratio 2.29; 95% confidence interval 1.44-3.66).

CONCLUSION

More than 10% of patients receiving quetiapine or haloperidol therapy developed SQTP, and many of them were exposed to risk factors for SQTP. SQTP in quetiapine users was significantly associated with increased risks of ventricular arrhythmias and sudden cardiac death. Clinicians should be vigilant for ventricular arrhythmias in quetiapine users who have risk factors for SQTP.

[Antipsychotic Treatment of Alcohol Withdrawal Syndrome with Focus on Delirium Tremens: a Systematic Review]

BACKGROUND

Delirium tremens (DT) is a common complication of alcohol withdrawal. Pharmacological treatment of hospitalized patients with DT is important in addiction medicine but also in other medical disciplines where DT can occur as a complication of hospitalization. Patients suffering from DT require treatment with benzodiazepines (short-acting benzodiazepines for elderly patients to reduce accumulation), and in cases of psychotic symptoms, treatment with antipsychotics. Benzodiazepines are a first-line treatment for DT. A specific guideline for the use of antipsychotics has yet to be developed. This review discusses the current guidelines and literature on the antipsychotic treatment options in DT.

AIM

Systematic presentation of relevant antipsychotics for the treatment of DT.

METHODS

A systematic literature search was conducted using Scopus and PubMed. The last search was conducted on May 22nd 2022. Original articles and reviews on antipsychotic treatment in alcohol withdrawal and DT were included in this review. Further, international guidelines were also considered. The review was registered using the PROSPERO database (https://www.crd.york.ac.uk/prospero/); CRD42021264611.

RESULTS

Haloperidol is mainly recommended for use in the intensive care unit. There is little literature on the use of atypical antipsychotics to treat DT. Treatment with antipsychotics always should be combined with benzodiazepines, and physicians should watch out for complications like neuroleptic malignant syndrome, QTc interval prolongation, extrapyramidal symptoms and withdrawal seizures resulting from lowering the threshold for seizures.

CONCLUSION

Antipsychotic treatment should depend on the experience of the physician. Beside haloperidol, no other clear recommendations are available.

Use of Electrocardiogram Monitoring in Adult Patients Taking High-Risk QT Interval Prolonging Medicines in Clinical Practice: Systematic Review and Meta-analysis

Introduction

Electrocardiogram (ECG) monitoring is an important tool to detect and mitigate the risk of potentially fatal drug-induced QT prolongation and remains fundamental in supporting the quality use of high-risk QT interval prolonging medicines.

Objective

The aim of this systematic review was to determine the prevalence of baseline and/or follow-up ECG use in adult patients taking high-risk QT interval prolonging medicines in clinical practice.

Methods

CINAHL, Cochrane Library, Embase, PubMed, EThOS, OpenGrey and Proquest were searched for studies in adults that reported ECG use at baseline and/or at follow-up in relation to the initiation of a high-risk QT interval prolonging medicine in any clinical setting; either hospital or non-hospital. Two reviewers independently assessed the methodological quality of included studies. Proportional meta-analysis was conducted with all studies reporting baseline ECG use, before medicine initiation, and follow-up ECG use, within 30 days of medicine initiation.

Results

There was variability in baseline ECG use according to the practice setting. The prevalence of baseline ECG use for high-risk QT interval prolonging medicines was moderate to high in the hospital setting at 75.1% (95% CI 64.3–84.5); however, the prevalence of baseline ECG use was low in the non-hospital setting at 33.7% (95% CI 25.8–42.2). The prevalence of follow-up ECG use was low to moderate in the hospital setting at 39.2% (95% CI 28.2–50.8) and could not be determined for the non-hospital setting.

Conclusions

The use of ECG monitoring for high-risk QT interval prolonging medicines is strongly influenced by the clinical practice setting. Baseline ECG use occurs more in the hospital setting in comparison to the non-hospital setting. There is lower use of follow-up ECG in comparison to baseline ECG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-022-01215-x.

Risk assessment tools for QT prolonging pharmacotherapy in older adults: a systematic review

Purpose

Many drugs are associated with the risk of QT prolongation and torsades de pointes (TdP), and different risk assessment tools (RATs) are developed to help clinicians to manage related risk. The aim of this systematic review was to summarize the evidence of different RATs for QT prolonging pharmacotherapy.

Methods

A systematic review was conducted using PubMed and Scopus databases. Studies concerning risk assessment tools for QT prolonging pharmacotherapy, including older adults, were included. Screening and selection of the studies, data extraction, and risk of bias assessment were undertaken.

Results

A total of 21 studies were included, involving different risk assessment tools. Most commonly used tools were risk scores (n = 9), computerized physician order entry systems (n = 3), and clinical decision support systems (n = 6). The tools were developed mainly for physicians and pharmacists. Risk scores included a high number of risk factors, both pharmacological and non-pharmacological, for QT prolongation and TdP. The inclusion of patients’ risk factors in computerized physician order entry and clinical decision support systems varied.

Conclusion

Most of the risk assessment tools for QT prolonging pharmacotherapy give a comprehensive overview of patient-specific risks of QT prolongation and TdP and reduce modifiable risk factors and actual events. The risk assessment tools could be better adapted to different health information systems to help in clinical decision-making. Further studies on clinical validation of risk assessment tools with randomized controlled trials are needed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-022-03285-3.

Acute transaminitis after initial days of starting haloperidol

Haloperidol is a first-generation antipsychotic butyrophenone that is lipophilic, readily absorbed, and extensively metabolized in the liver. The occurrence of elevated liver enzymes with haloperidol is reported to be 2.4% with cases generally occurring in the setting of chronic use. In this case, we present a patient who developed elevated liver enzymes 1-2 days after starting haloperidol treatment on two separate occasions and in the context of negative hepatic viral and autoimmune serology. Liver enzymes consistently had alanine transaminase > aspartate transaminase and peaked at 288 U/L prior to discontinuation of the medication. The patient was taken off haloperidol after serology resulted and clozapine regimen started. He was able to tolerate clozapine well with recovery of his transaminitis and psychiatric stabilization.

Drug-induced Proarrhythmia and Torsade de Pointes: A Primer for Students and Practitioners of Medicine and Pharmacy

Multiple marketing withdrawals due to proarrhythmic concerns occurred in the United States, Canada, and the United Kingdom in the late 1980s to early 2000s. This primer reviews the clinical implications of a drug's identified proarrhythmic liability, the issues associated with these safety-related withdrawals, and the actions taken by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) and by regulatory agencies in terms of changing drug development practices and introducing new nonclinical and clinical tests to asses proarrhythmic liability. ICH Guidelines S7B and E14 were released in 2005. Since then, they have been adopted by many regional regulatory authorities and have guided nonclinical and clinical proarrhythmic cardiac safety assessments during drug development. While this regulatory paradigm has been successful in preventing drugs with unanticipated potential for inducing the rare but potentially fatal polymorphic ventricular arrhythmia torsade de pointes from entering the market, it has led to the termination of drug development programs for other potentially useful medicines because of isolated results from studies with limited predictive value. Research efforts are now exploring alternative approaches to better predict potential proarrhythmic liabilities. For example, in the domain of human electrocardiographic assessments, concentration-response modeling conducted during phase 1 clinical development has recently become an accepted alternate primary methodology to the ICH E14 "thorough QT/QTc" study for defining a drug's corrected QT interval prolongation liability under certain conditions. When a drug's therapeutic benefit is considered important at a public health level but there is also an identified proarrhythmic liability that may result from administration of the single drug in certain individuals and/or drug-drug interactions, marketing approval will be accompanied by appropriate directions in the drug's prescribing information. Health-care professionals in the fields of medicine and pharmacy need to consider the prescribing information in conjunction with individual patients' clinical characteristics and concomitant medications when prescribing and dispensing such drugs.

Validation and Clinical Utility of the hERG IC50:Cmax Ratio to Determine the Risk of Drug-Induced Torsades de Pointes: A Meta-Analysis

BACKGROUND

Use of the QT interval corrected for heart rate (QTc) on the electrocardiogram (ECG) to predict torsades de pointes (TdP) risk from culprit drugs is neither sensitive nor specific. The ratio of the half-maximum inhibitory concentration of the hERG channel (hERG IC50) to the peak serum concentration of unbound drug (C_max ) is used during drug development to screen out chemical entities likely to cause TdP.

PURPOSE

To validate the use of the hERG IC50:C_max ratio to predict TdP risk from a culprit drug by its correlation with TdP incidence.

DATA SOURCES

Medline (between 1966 and March 2017) was accessed for hERG IC50 and C_max values from the antihistamine, fluoroquinolone, and antipsychotic classes to identify cases of drug-induced TdP. Exposure to a culprit drug was estimated from annual revenues reported by the manufacturer.

STUDY SELECTION

Inclusion criteria for TdP cases were provision of an ECG tracing that demonstrated QTc prolongation with TdP and normal serum values of potassium, calcium, and magnesium. Cases reported in patients with a prior rhythm disturbance and those involving a drug interaction were excluded.

DATA EXTRACTION AND SYNTHESIS

The Meta-Analysis of Observational Studies in Epidemiology checklist was used for epidemiological data extraction by two authors.

MAIN OUTCOME AND MEASURE

Negligible risk drugs were defined by an hERG IC50:C_max ratio that correlated with less than a 5% chance of one TdP event for every 100 million exposures (relative risk [RR] 1.0).

RESULTS

The hERG IC50:C_max ratio correlated with TdP risk (0.312; 95% confidence interval 0.205-0.476, p<0.0001), a ratio of 80 (RR 1.0). The RR from olanzapine is on par with loratadine; ziprasidone is comparable with ciprofloxacin. Drugs with an RR greater than 50 include astemizole, risperidone, haloperidol, and thioridazine.

CONCLUSIONS

The hERG IC50:C_max ratio was correlated with TdP incidence for culprit drugs. This validation provides support for the potential use of the hERG IC50:C_max ratio for clinical decision making in instances of drug selection where TdP risk is a concern.

Incidence of Torsade de Pointes in a tertiary hospital population

BACKGROUND

Multiple risk factors play a role in the development of QTc-prolongation and Torsade de Pointes (TdP). Cases of TdP are underreported and data on the incidence of TdP is scarce. The aim of this study was to investigate the incidence of TdP in a Belgian university hospital and describe the characteristics of TdP-cases using a risk score.

METHODS

All cases from 2011 till 2013 coded with the ICD-9 code 427.1 in the University Hospitals of Leuven were selected. The medical files were reviewed and demographical, medical, medication and electrocardiographic data were collected. We focused on TdP-cases that were probably caused by the acquired long QT-syndrome. The RISQ-PATH score was used to quantify the risk in these cases (≥10 points as high risk for QTc-prolongation/TdP).

RESULTS

Over three years, 41 TdP-cases were identified of which 19 cases were secondary to the acquired long QT-syndrome (52.6% females, mean age of 74±12years). This corresponds with an incidence of 0.16‰/year in a hospital population. Most of the patients (N=17) were treated with at least one QTc-prolonging drug (most frequently amiodarone, sotalol and furosemide) of whom 12 patients with ≥1 QTc-prolonging drug of list 1 of CredibleMeds. Fifteen patients had an electrocardiogram in a 24-hours interval before the TdP with a prolonged QTc-interval (≥450/470ms). All the patients had a RISQ-PATH score≥10.

CONCLUSIONS

Although the incidence of 0.16‰/year might seem low, this means that approximately 173 possibly lethal TdP-cases can be expected in Belgian hospitals each year. All TdP-cases were associated with a high RISQ-PATH score.

Which QT Correction Formulae to Use for QT Monitoring?

Background

Drug safety precautions recommend monitoring of the corrected QT interval. To determine which QT correction formula to use in an automated QT‐monitoring algorithm in our electronic medical record, we studied rate correction performance of different QT correction formulae and their impact on risk assessment for mortality.

Methods and Results

All electrocardiograms (ECGs) in patients >18 years with sinus rhythm, normal QRS duration and rate <90 beats per minute (bpm) in the University Hospitals of Leuven (Leuven, Belgium) during a 2‐month period were included. QT correction was performed with Bazett, Fridericia, Framingham, Hodges, and Rautaharju formulae. In total, 6609 patients were included (age, 59.8±16.2 years; 53.6% male and heart rate 68.8±10.6 bpm). Optimal rate correction was observed using Fridericia and Framingham; Bazett performed worst. A healthy subset showed 99% upper limits of normal for Bazett above current clinical standards: men 472 ms (95% CI, 464–478 ms) and women 482 ms (95% CI 474–490 ms). Multivariate Cox regression, including age, heart rate, and prolonged QTc, identified Framingham (hazard ratio [HR], 7.31; 95% CI, 4.10–13.05) and Fridericia (HR, 5.95; 95% CI, 3.34–10.60) as significantly better predictors of 30‐day all‐cause mortality than Bazett (HR, 4.49; 95% CI, 2.31–8.74). In a point‐prevalence study with haloperidol, the number of patients classified to be at risk for possibly harmful QT prolongation could be reduced by 50% using optimal QT rate correction.

Conclusions

Fridericia and Framingham correction formulae showed the best rate correction and significantly improved prediction of 30‐day and 1‐year mortality. With current clinical standards, Bazett overestimated the number of patients with potential dangerous QTc prolongation, which could lead to unnecessary safety measurements as withholding the patient of first‐choice medication.