Development of a risk score for QTc-prolongation: the RISQ-PATH study

An Updated Safety Review of the Relationship Between Atypical Antipsychotic Drugs, the QTc Interval and Torsades de Pointe As: Implications for Clinical Use

INTRODUCTION

The rising prevalence of psychiatric disorders has resulted in a significant increase in the use of antipsychotic medications. These agents may prolong the corrected QT interval (QTc), running the risk of precipitating ventricular arrhythmias, notably Torsades de Pointes (TdP). Current recommendations vary regarding the optimal approach to safe prescribing practices and QTc surveillance for antipsychotics. This review summarizes the current literature addressing these clinical concerns.

AREAS COVERED

The physiologic basis of the QTc interval, mechanisms underlying its susceptibility to pharmacological influence, specific risks associated with atypical antipsychotic agents, and recommendations for safe prescription practices. We performed a literature review using Pubmed and Embase databases, searching for 'antipsychotics' and 'torsades de pointes.'

EXPERT OPINION

Finding a safe and universally accepted protocol for prescribing antipsychotics remains a persistent challenge in medicine. Predictive models that integrate clinical history with demographic and ECG characteristics can help estimate an individual's susceptibility to therapy-associated risks, including QTc prolongation. Agents such as ziprasidone and iloperidone are significantly more likely to prolong the QTc interval compared to others such as brexpiprazole, cariprazine, olanzapine, and clozapine. A personalized approach using low-risk medications when clinically feasible, and at the lowest efficacious dose, offers a promising path toward safer antipsychotic prescribing.

Determining sensitivity and specificity of risk scores for QTc interval prolongation in hemato-oncology patients prescribed systemic antifungal therapy: a retrospective cross-sectional study

BACKGROUND

QTc interval prolongation can result in potentially lethal arrhythmias. One risk factor is QTc-prolonging drugs, including some antifungals often used in hemato-oncology patients. Screening tools for patients at risk have not yet been investigated in this patient population.

AIM

Our aim was to evaluate the sensitivity and specificity of five QTc risk scores in hemato-oncology patients receiving systemic antifungal therapy.

METHOD

Data were retrieved from an internal study database including adult hemato-oncology patients prescribed systemic antifungal therapy. Data on QTc-prolonging medication, risk factors for QTc prolongation, and electrocardiograms (ECG) were collected retrospectively for a period of 12 months. The QTc risk scores according to Tisdale, Vandael, Berger, Bindraban, and Aboujaoude as well as their sensitivity and specificity were calculated.

RESULTS

During the evaluated period, 77 patients were prescribed systemic antifungals resulting in 187 therapy episodes. Regarding therapy episodes, median age was 56 years (IQR 44-68), 41% (77) were female, and a median of 3 QTc-prolonging drugs were prescribed (range 0-6). ECGs were available for 45 (24%) of the therapy episodes 3-11 days after initiation of the antifungal therapy, 22 of which showed QTc prolongation. Regarding these 45 therapy episodes, sensitivity and specificity of the risk scores were calculated as follows: Tisdale 86%/22%, Vandael 91%/35%, Berger 32%/83%, Bindraban 50%/78%, Aboujaoude 14%/87%.

CONCLUSION

The QTc risk scores according to Tisdale and Vandael showed sufficient sensitivity for risk stratification in the studied patient population. In contrast, risk scores according to Berger, Bindraban, and Aboujaoude cannot be considered suitable due to poor sensitivity.

QTc Interval Prolongation as an Adverse Event of Azole Antifungal Drugs: Case Report and Literature Review

QTc prolongation and torsade de pointes (TdP) are significant adverse events linked to azole antifungals. Reports on QTc interval prolongation caused by these agents are limited. In this study, we report a case of a 77-year-old male with cardiovascular disease who experienced QTc prolongation and subsequent TdP while being treated with fluconazole for Candida albicans-induced knee arthritis. Additionally, a literature review was conducted on cases where QTc prolongation and TdP were triggered as adverse events of azole antifungal drugs. The case study detailed the patient's experience, whereas the literature review analyzed cases from May 1997 to February 2023, focusing on patient demographics, underlying diseases, antifungal regimens, concurrent medications, QTc changes, and outcomes. The review identified 16 cases, mainly in younger individuals (median age of 29) and women (75%). Fluconazole (63%) and voriconazole (37%) were the most common agents. Concurrent medications were present in 75% of cases, and TdP occurred in 81%. Management typically involved discontinuing or switching antifungals and correcting electrolytes, with all patients surviving. Risk assessment and concurrent medication review are essential before starting azole therapy. High-risk patients require careful electrocardiogram monitoring to prevent arrhythmias. Remote monitoring may enhance safety for patients with implanted devices. Further studies are needed to understand risk factors and management strategies.

Case report of QT interval prolongation induced by anamorelin in an obese patient with non-small cell lung cancer

BACKGROUND

Anamorelin, a drug to treat cancer cachexia, binds to ghrelin receptors and improves body weight and appetite. In clinical trials in Japan, patients experienced a 10.7% frequency of stimulant conduction system depression as a severe side effect. Although rare, anamorelin sometimes causes fatal arrhythmias. Because patients with cancer cachexia are often underweight, data on the safety of anamorelin in obese patients are lacking. We report a case of QT interval prolongation after anamorelin administration to an obese patient with non-small cell lung cancer.

CASE PRESENTATION

A female patient with a body mass index of 30 kg/m2 underwent immunotherapy for lung adenocarcinoma. She presented with severe weight loss, anorexia, and fatigue. She had no history of heart disease. On day 12, after administration of anamorelin 100 mg once daily, the patient developed nausea, diarrhea, and anorexia, which were considered cancer immunotherapy-induced immune-related adverse events, and she was admitted to the hospital. An electrocardiogram (ECG) on admission showed a QTc interval of 502 ms. On admission, her hepatic function was Child-Pugh class B, and anamorelin was discontinued the next day. On day 3 after anamorelin discontinuation, the QTc interval was prolonged by up to 557 ms, then decreased to 490 ms on day 6, and improved to 450 ms on day 16. Re-administration of anamorelin was avoided.

CONCLUSIONS

When administering anamorelin to obese patients, we should be aware of the potential for stimulatory conduction system depression, as in underweight patients. Therefore, we should monitor patients by ECG from the early stages of anamorelin administration. Anamorelin is lipophilic, and its volume of distribution is increased in obese patients. Consequently, obese patients may continue to have QT interval prolongation after discontinuation of anamorelin, requiring long-term side-effect monitoring.

A quality improvement study of the implementation and initial results of a pragmatic clinical decision support system in the community pharmacy setting

BACKGROUND

A six year collaboration between academics, community pharmacists and informaticians, led to the development of nine guidelines for a clinical decision support system, enhancing community pharmacists' ability to address drug-related problems and improve care.

AIM

The objective of this study was to assess the effectiveness of clinical decision support system rules in enhancing medication management within the community pharmacy setting. This was achieved through retrospective monitoring of real-world usage and measuring the pharmacotherapeutic impact of the rules.

METHOD

In 2019, a retrospective observational evaluation appraised the acceptance rate of the clinical decision support system components in 490 Belgian pharmacies. Among these, 51 pharmacies underwent a longitudinal analysis involving (i) co-prescription of methotrexate and folic acid, (ii) gastroprotection with non-steroidal anti-inflammatory drugs, and (iii) drug combinations causing QT prolongation. The study period spanned one year pre-launch, one year post-launch, and two years post-launch.

RESULTS

Of the targeted pharmacies, 80% used 7 of the 9 rules. After four years, methotrexate-folic acid co-prescription increased 4%, reaching 79.8%. Gastroprotection improved by 3% among older patients and 7.47% in younger individuals (< 70 year) with multiple risk factors. The QT prolongation rules faced implementation difficulties.

CONCLUSION

Pharmacists' acceptance of the developed rules was high and coincided with a decline in drug-related problems, holding potential public health impact. This real-world data can inform the future implementation of such systems, as it demonstrated the need for more detailed data-gathering and more intensive training of pharmacists in the handling of more complex problems such as QT prolongation.

Navigating the pharmacologic complexities of QTc prolongation: assessing the cumulative burden in individuals with serious mental illness

The scientific progress made in the pharmacologic management of serious mental illness (SMI) has been significant. However, the benefits of medication management must continually be weighed against the risks of adverse effects of the agents prescribed. While many medications pose increased danger of QTc prolongation, which may result in malignant arrhythmia and sudden cardiac death, the combination of medications contributing QTc risk can result in an impact of unpredictable pharmacodynamic magnitude. Pharmacists play a key role in communicating QTc risks to prescribers, however little if any clinical guidance informs clinicians of specific actions to take when initiating or continuing a clinically necessary combination that poses risk. This study is a cross-sectional view of Med Safety Scan (MSS) QT prolongation risk scores, generated from the ranking tool available from the CredibleMeds website, intended to provide greater understanding of overall risk of QT burden to assist in the prescribing of medications to patients with SMI in a psychiatric hospital.

Elderly patients whose hospitalization was medication-related were more likely to receive medication recommendations by clinical pharmacist than patients whose hospitalization was unlikely medication-related in non-geriatric units

BACKGROUND

Elderly patients are often polymedicated, and drug-related hospitalizations are common in this population. In our hospital, pharmacists from the mobile geriatric team (MGT) coordinate medication reviews (MR) for elderly patients hospitalized in non-geriatric wards, to prevent iatrogenic.

OBJECTIVE

The aim of this work is to determine whether the drug-related origin of hospitalizations can be considered as a targeting criterion for performing MRs.

MATERIAL AND METHOD

We conducted a retrospective study of data from patients who received a MGT's MR between March 2021 and December 2022, from a single center of more than 1000 beds. The drug-related origin of the hospitalization was estimated as probable or unlikely by the AT-HARM10 tool. Between the two groups, we compared the number of potentially inappropriate prescriptions detected by the PIM-check and START/STOPP tools, drug-drug interactions (DI), unintended discrepancies (UDI) at entry reconciliation, the drug burden index (DBI), and the number of drug-related problems (DRP) i.e., START/STOPP score + DI + UDI. Linear regression of the number of DRP by AT-HARM10 score was computed.

RESULTS

110 patients were included. 56 hospitalizations were estimated MRH and 54 non-MRH. Mean age (85.1 ± 7.0), ADL (3.8 ± 1.9), IADL (2.0 ± 1.6), and number of medications at entry (8.9 ± 3.8) were comparable in the 2 groups. Compared with non-MRH group, MRH group had a higher number of START/STOPP criteria (5.7 ± 3.5 vs 3.0 ± 2.6; p < 0.05), PIM-check overuses (2.1 ± 1.7 vs 1.4 ± 1.4; p < 0.05), DI (8.4 ± 9.0 vs 4.7 ± 4.7; p < 0.05), UDI at entry (4.0 ± 3.34 vs 2.2 ± 2.1; p < 0.05), and higher DBI score (0.9 ± 0.7 vs 0.3 ± 0.4; p < 0.05). The number of DRP was higher in group P (17.6 ± 10.8 vs 9.8 ± 6.3; p < 0.00.5). Linear regression showed a positive correlation between AT-HARM10 score and the number of DRP (r = 0.5, p < 0.05) with a coefficient of 7.7 (CI95% = [4.3; 11.1]) and an intercept of 9.8.

DISCUSSION

These results allow us to consider AT-HARM10 score as a targeting criterion for performing MR for elderly patients, as part of a curative approach to drug iatrogenic for these patients.

QTc prolongation risk among patients receiving oral targeted antineoplastic medications: A real-world community-based oncology analysis

Introduction

Thirty oral targeted antineoplastic agents are associated with prolongation of the QT interval. However, limited data exists regarding QTc prolongation and associated risk factors in the ambulatory oncology setting.

Methods

This retrospective study was completed to describe QTc prolongation incidence among patients receiving oral targeted tyrosine kinase inhibitors (TKI) and identify potential risk factors in the ambulatory community-based oncology clinic.

Results

Of the 341 patients identified as receiving oral TKI, 49 with a baseline and follow-up ECG were included. The incidence of QTc prolongation (QTc &gt; 470 ms in males, QTc &gt; 480 ms in females, or &gt;20 ms increase in QTc from baseline) was 24%. Three patients developed significant QTc prolongation (QTc &gt;500 ms or &gt;60 ms increase in QTc from baseline). No patients discontinued therapy primarily due to QTc prolongation or experienced symptomatic torsades de pointes. Analysis of risk factors demonstrated that patients with QTc prolongation were more likely to receive concomitant therapy with a loop diuretic (41% vs 11%, respectively, p=0.029).

Discussion

The frequency of QTc prolongation may be higher in the real-world setting than that observed in clinical trials; however, continuation of therapy may be possible. Patients receiving concomitant loop diuretics should be monitored more closely for QTc prolongation and electrolyte abnormalities.

Development in Prescriptions of Contraindicated and Potentially Harmful QT Interval-Prolonging Drugs in a Large Geriatric Inpatient Cohort From 2011 to 2021

Regulatory authorities put major emphasis on QT (interval)-prolonging properties of new molecular entities. Product information/Summaries of Product Characteristics (SmPCs) of multiple drugs contain warnings or contraindications regarding QT prolongation, e.g., on coadministration of QT-prolonging drugs (QT drugs). To characterize the development of the QT drug burden, we performed a trend analysis of prescriptions and co-prescriptions of QT drugs in a large geriatric inpatient cohort. The German SmPCs (status of 2014 and of 2021) and the year-wise listings in the CredibleMeds^® database from 2011 to 2021 were used as sources. There were 402,631 geriatric cases included. The group of QT drugs according to SmPCs in 2014, which must not be combined with other QT drugs, was less frequently involved in contraindicated co-prescriptions in 2021 compared with 2015 (3.0% (2.5-3.7%) of cases with at least one of those drugs in 2021 vs. 4.0% (3.5-4.5%) in 2015), with citalopram, escitalopram, and amiodarone involved in nearly 90% of the co-prescriptions. The number of CredibleMeds-QT-drugs per patient increased from 0.4 (SD=1.1) in 2011 to 1.8 (SD=3.9) in 2021. The percentage of contraindicated co-prescriptions of drugs with known risk for torsade de pointes according to CredibleMeds^® listings at the beginning of the respective years increased from 1.7% in 2011 to 6.1% in 2021. Considering the regularly updated CredibleMeds^® QT drugs list, the contraindicated co-prescriptions of QT drugs markedly increased in the last decade. If prescribers considered only the few most frequently (co-) prescribed QT drugs, then most of the medication errors regarding QT drugs could be prevented.

Association of QT interval-prolonging drugs with clinical trial eligibility in patients with advanced cancer

Introduction

Drug-induced prolongation of the heart rate-corrected QT interval (QTc) is associated with increased risk for the potentially fatal arrhythmia torsades de pointes. Due to arrhythmia risk, clinical trials with cancer therapeutics often exclude patients based on thresholds for QTc prolongation. Our objective was to assess associations between prescriptions for QT-prolonging drugs and the odds of meeting cancer trial exclusionary QTc thresholds in a cohort of adults with advanced cancer.

Methods

Electronic health records were retrospectively reviewed for 271 patients seen at our institutional molecular solid tumor clinic. Collected data included demographics, QTc measurements, ventricular arrhythmia-related diagnoses, and all inpatient and outpatient prescriptions. Potential associations were assessed between demographic and clinical variables, including prescriptions for QT-prolonging drugs, and QTc measurements.

Results

Women had longer median QTc measurements than men (p = 0.030) and were prescribed more QT-prolonging drugs during the study (p = 0.010). In all patients, prescriptions for QT-prolonging drugs were associated with longer median and maximum QTc measurements at multiple assessed time points (i.e., for QT-prolonging drugs prescribed within 10, 30, 60, and 90 days of QTc measurements). Similarly, the number of QT-prolonging drugs prescribed was correlated with longer median and maximum QTc measurements at multiple time points. Common QTc-related exclusionary criteria were collected from a review of ClinicalTrials.gov for recent cancer clinical trials. Based on common exclusion criteria, prescriptions for QT-prolonging drugs increased the odds of trial exclusion.

Conclusion

This study demonstrates that prescriptions for QT-prolonging drugs were associated with longer QTc measurements and increased odds of being excluded from cancer clinical trials.

Prolonged QT Interval in Cirrhosis: Twisting Time?

Approximately 30% to 70% of patients with cirrhosis have QT interval prolongation. In patients without cirrhosis, QT prolongation is associated with an increased risk of ventricular arrhythmias, such as torsade de pointes (TdP). In cirrhotic patients, there is likely a significant association between the corrected QT (QTc) interval and the severity of liver disease, and possibly with increased mortality. We present a stepwise overview of the pathophysiology and management of acquired long QT syndrome in cirrhosis. The QT interval is mainly determined by ventricular repolarization. To compare the QT interval in time it should be corrected for heart rate (QTc), preferably by the Fridericia method. A QTc interval >450 ms in males and >470 ms in females is considered prolonged. The pathophysiological mechanism remains incompletely understood, but may include metabolic, autonomic or hormonal imbalances, cirrhotic heart failure and/or genetic predisposition. Additional external risk factors for QTc prolongation include medication (IKr blockade and altered cytochrome P450 activity), bradycardia, electrolyte abnormalities, underlying cardiomyopathy and acute illness. In patients with cirrhosis, multiple hits and cardiac-hepatic interactions are often required to sufficiently erode the repolarization reserve before long QT syndrome and TdP can occur. While some risk factors are unavoidable, overall risk can be mitigated by electrocardiogram monitoring and avoiding drug interactions and electrolyte and acidbase disturbances. In cirrhotic patients with prolonged QTc interval, a joint effort by cardiologists and hepatologists may be useful and significantly improve the clinical course and outcome.

Use of Drugs Associated with QT Interval Prolongation at the Hospital Level during the COVID-19 Pandemic in Colombia

Background. Many of the therapeutic proposals for COVID-19 have been associated with adverse effects, including the risk of QT interval prolongation and torsades de pointes (TdP). The objective was to determine the use of drugs with a risk of QT interval prolongation in 21 clinics/hospitals in Colombia from January to December 2020. Methods. This cross-sectional study identified drug use according to pharmacological groups with potential risk of QT interval prolongation according to a risk classification: conditional, possible, and known risk of TdP. Descriptive analyses were performed. Results. A total of 355,574 patients who received QT-prolonging drugs were identified (equivalent to 51.4% of all inpatients treated during the study period). Of the group of patients on QT drugs, 54.4% used at least one drug with conditional risk, 52.6% with possible risk, and 40.3% with known risk. The most commonly used belonged to the group of drugs for the nervous system (63.0%), alimentary tract and metabolism (56.8%), anti-infectives for systemic use (13.0%), and the cardiovascular system (11.7%). On average, patients received $2.0\pm 1.5$ risk drugs. Regarding drugs initially considered against COVID-19, 2,120 patients (0.6%) received azithromycin, 802 (0.2%) received chloroquine, 517 received hydroxychloroquine (0.1%), and 265 received lopinavir/ritonavir (0.1%). Conclusion. The high proportion of patients treated at the hospital level who receive drugs with risk of prolonging the QT interval should alert those responsible for their care to avoid fatal outcomes, especially during the COVID-19 epidemic, when some QT drugs are being used more frequently.

Is the association of QTc with atrial fibrillation and stroke in cohort studies a matter of time?

Objectives

To investigate the association of the heart rate-corrected QT interval (QTc) with the risk of atrial fibrillation (AF) and ischaemic stroke.

Methods

We estimated the risk of AF and ischaemic stroke associated with QTc duration (ms) by Cox regression in study participants from the cohort of 60-year-old men and women from Stockholm (60YO) (n=4232). Univariate and multivariate adjusted risk estimates were expressed as HR and 95% CI. Main results were validated in elderly patients with AF, included in the Carebbean-e study, where an ECG in sinus rhythm (SR) (ECG-SR) recorded before the ECG diagnostic for (ECG-AF) was available (n=803). We estimated the correlation between the time interval (years) between the ECG-SR and ECG-AF with the QTc duration, by the Spearman correlation coefficient (rho).

Results

In the 60YO, the highest QTc duration quartile (>427 ms) associated with the AF risk (n=435) with a multivariable adjusted HR of 1.68 and 95% CI (1.26 to 2.24). No association was observed with ischaemic stroke. In the Carebbean-e study, no significant association was observed between the QTc duration measured on the ECG-SR and risk of ischaemic stroke during follow-up. QTc duration showed an inverse correlation (rho: −0.26, p<0.0001) with the time interval intercurred between ECG-SR and ECG-AF.

Conclusions

The association of QTc duration with AF risk might depend on the time interval between the QTc measurement and the clinical diagnosis of AF. No association was observed between QTc duration and ischaemic stroke.

Study of the indications for macrolide prescriptions in a Colombian population

Introduction

The inappropriate use of antibiotics is associated with a greater risk for antimicrobial resistance, high health care costs, adverse events, and worse clinical outcomes.

Objective

To determine the prescription patterns and approved and nonapproved indications for macrolides in a group of patients from Colombia.

Materials and methods

This was a cross-sectional study on the indications for the use of macrolides in outpatients registered in a drug-dispensing database of approximately 8.5 million people affiliated with the Colombian health system. Sociodemographic, pharmacological, and clinical variables were considered.

Results

A total of 9.344 patients had received a macrolide prescription; their median age was 40.1 years (interquartile range: 27.1-53.3 years) and 58.3% were women. The most commonly prescribed macrolide was azithromycin (38.8%) most frequently for Helicobacter pylori infection (15.9%) and pneumonia treatment (15.8%). A total of 31.3% of the prescriptions were used for unapproved indications: common cold (7.8%), COVID-19 (4.0%), and acute bronchitis (3.5%). Residence in the Caribbean region (OR=1.17; 95%CI 1.05-1.31), dental prescriptions (OR=2.75; 95%CI 1.91-3.96), presence of chronic respiratory comorbidities (OR=1.30; 95%CI 1.08-1.56), and prescription of erythromycin (OR=3.66; 95%CI 3.24-4.14) or azithromycin (OR=2.15; 95%CI 1,92-2.41) were associated with a higher probability of macrolide use for unapproved indications while being 18-64 years old (OR=0.81; 95%CI 0.71-0.93) or 65 years or older (OR=0.77; 95%CI 0.63-0.94) and residing in Bogotá-Cundinamarca (OR=0.74; 95%CI 0.65-0.85) were associated with reduced risk.

Conclusions

Most patients received macrolides for respiratory tract infections; erythromycin and azithromycin were used for unapproved indications in people under 18 years of age and those with chronic respiratory diseases.

Practical Approaches to Antipsychotic-Associated Corrected QT Interval Prolongation in Patients With Serious Mental Illness: A Review of Cases

BACKGROUND

There is no consensus for assessment and management of patients with serious mental illness (SMI) who are at risk for cardiac morbidity and mortality due to antipsychotic-associated QTc prolongation.

OBJECTIVE

The objective of this review was to assess methods for risk scoring, QT correction calculation, and clinical management in SMI patients with antipsychotic-associated QTc prolongation.

METHODS

A search was performed in PubMed for case reports that described QTc prolongation in adult patients with schizophrenia or bipolar disorder prescribed an antipsychotic. Reports published in North America between 2000 and 2020 were eligible. The Mayo, Tisdale, and RISQ-PATH scoring tools were applied to cases to categorize risk level.

RESULTS

Seventeen cases were included. Most patients were prescribed a second-generation antipsychotic for schizophrenia, with baseline and maximum QTc values of 429 milliseconds and 545 milliseconds, respectively. The Mayo scoring tool identified 17 (100%) cases as "high risk," Tisdale identified 9 (53%) cases as "moderate risk" and 7 (41%) cases as "low risk," while RISQ-PATH identified 9 (53%) cases as "not low risk" and 8 (47%) cases as "low risk." Three cases reported the QT correction formula utilized (18%). The most common intervention to address antipsychotic-associated QTc prolongation was switching to a different antipsychotic (35%). Approximately one third of patients experienced Torsades de Pointes.

CONCLUSION

There is a lack of standardization for antipsychotic-associated QTc prolongation risk assessment and management in patients with SMI. This review provides real-world data representing actual clinical practice.

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.

Antifungal Drugs TDM: Trends and Update

PURPOSE

The increasing burden of invasive fungal infections results in growing challenges to antifungal (AF) therapeutic drug monitoring (TDM). This review aims to provide an overview of recent advances in AF TDM.

METHODS

We conducted a PubMed search for articles during 2016-2020 using "TDM" or "pharmacokinetics" or "drug-drug-interaction" with "antifungal," consolidated for each AF. Selection was limited to English language articles with human data on drug exposure.

RESULTS

More than 1000 articles matched the search terms. We selected 566 publications. The latest findings tend to confirm previous observations in real-life clinical settings. The pharmacokinetic variability related to special populations is not specific but must be considered. AF benefit-to-risk ratio, drug-drug interaction (DDI) profiles, and minimal inhibitory concentrations for pathogens must be known to manage at-risk situations and patients. Itraconazole has replaced ketoconazole in healthy volunteers DDI studies. Physiologically based pharmacokinetic modeling is widely used to assess metabolic azole DDI. AF prophylactic use was studied more for Aspergillus spp. and Mucorales in oncohematology and solid organ transplantation than for Candida (already studied). Emergence of central nervous system infection and severe infections in immunocompetent individuals both merit special attention. TDM is more challenging for azoles than amphotericin B and echinocandins. Fewer TDM requirements exist for fluconazole and isavuconazole (ISZ); however, ISZ is frequently used in clinical situations in which TDM is recommended. Voriconazole remains the most challenging of the AF, with toxicity limiting high-dose treatments. Moreover, alternative treatments (posaconazole tablets, ISZ) are now available.

CONCLUSIONS

TDM seems to be crucial for curative and/or long-term maintenance treatment in highly variable patients. TDM poses fewer cost issues than the drugs themselves or subsequent treatment issues. The integration of clinical pharmacology into multidisciplinary management is now increasingly seen as a part of patient care.

Content Validation of an Algorithm for the Assessment, Management and Monitoring of Drug-Induced QTc Prolongation in the Psychiatric Population

BACKGROUND

QTc interval (QTcI) prolongation leads to serious complications, making it a concern for clinicians. Assessing the risk of QTcI prolongation in the psychiatric population is important because they are exposed to multiple medications known to increase the risk of life-threatening arrhythmias.

AIM

The study aims to validate the content of an algorithm for the assessment, management and monitoring of drug-induced QTc prolongation in the psychiatric population.

METHODOLOGY

Qualitative semi-structured interviews of cardiologists, to gather information regarding their approach in assessing the risk of drug-induced QTc prolongation at the time of prescribing. After the interview, an orientation to the algorithm was provided with a link to a cross-sectional, anonymous survey. The online survey included quantitative and qualitative components to gather feedback on the relevance and appropriateness of each step in the algorithm.

RESULTS

Interview responses were incorporated into 4 themes. Responses indicated a lack of a unified protocol when assessing QTcI prolongation, which supports the need of an algorithm that includes a verified risk scoring tool. Quantitative survey results showed a mean score ranging from 3.08 to 3.67 out of 4 for the appropriateness of the algorithm's steps, 3.08 to 3.58 for the safety and 3.17 to 3.75 for the reliability of references used. Additional analysis using the modified kappa and I-CVI statistical measures indicate high validity of contents and high degree of agreement between raters. As per the open-ended questions, cardiologists supported the implementation of the algorithm; however, they recommended simplification of the steps as they appear to be cumbersome.

CONCLUSION

The results demonstrate that the implementation of the algorithm after minor alterations can prove to be useful as a tool for the risk assessment of QTc prolongation. Further validation of the algorithm with mental health pharmacists and clinicians will be conducted as a separate phase of the study.

Torsade de pointes: A nested case-control study in an integrated healthcare delivery system

Background

TdP is a form of polymorphic ventricular tachycardia which develops in the setting of a prolonged QT interval. There are limited data describing risk factors, treatment, and outcomes of this potentially fatal arrhythmia.

Objective

Our goals were as follows: (1) to validate cases presenting with Torsade de Pointes (TdP), (2) to identify modifiable risk factors, and (3) to describe the management strategies used for TdP and its prognosis in a real‐world healthcare setting.

Methods

Case–control study (with 2:1 matching on age, sex, and race/ethnicity) nested within the Genetic Epidemiology Research on Aging (GERA) cohort. Follow‐up of the cohort for case ascertainment was between January 01, 2005 and December 31, 2018.

Results

A total of 56 cases of TdP were confirmed (incidence rate = 3.6 per 100,000 persons/years). The average (SD) age of the TdP cases was 74 (13) years, 55 percent were female, and 16 percent were non‐white. The independent predictors of TdP were potassium concentration <3.6 mEq/L (OR = 10.6), prior history of atrial fibrillation/flutter (OR = 6.2), QTc >480 ms (OR = 4.4) and prior history of coronary artery disease (OR = 2.6). Exposure to furosemide and amiodarone was significantly greater in cases than in controls. The most common treatment for TdP was IV magnesium (78.6%) and IV potassium repletion (73.2%). The in‐hospital and 1‐year mortality rates for TdP cases were 10.7% and 25.0% percent, respectively.

Conclusions

These findings may inform quantitative multivariate risk indices for the prediction of TdP and could guide practitioners on which patients may qualify for continuous ECG monitoring and/or electrolyte replacement therapy.

Development of a Risk Score for QT Prolongation in the Intensive Care Unit Using Time-Series Electrocardiogram Data and Electronic Medical Records

Objective

Drug-induced QT prolongation can lead to life-threatening arrhythmia. In the intensive care unit (ICU), various drugs are administered concurrently, which can increase the risk of QT prolongation. However, no well-validated method to evaluate the risk of QT prolongation in real-world clinical practice has been established. We developed a risk scoring model to continuously evaluate the quantitative risk of QT prolongation in real-world clinical practice in the ICU.

Methods

Continuous electrocardiogram (ECG) signals measured by patient monitoring devices and Electronic Medical Records data were collected for ICU patients. QT and RR intervals were measured from raw ECG data, and a corrected QT interval (QTc) was calculated by Bazett's formula. A case-crossover study design was adopted. A case was defined as an occurrence of QT prolongation ≥12 hours after any previous QT prolongation. The patients served as their own controls. Conditional logistic regression was conducted to analyze prescription, surgical history, and laboratory test data. Based on the regression analysis, a QTc prolongation risk scoring model was established.

RESULTS

In total, 811 ICU patients who experienced QT prolongation were included in this study. Prescription information for 13 drugs was included in the risk scoring model. In the validation dataset, the high-risk group showed a higher rate of QT prolongation than the low-and low moderate-risk groups.

Conclusions

Our proposed model may facilitate risk stratification for QT prolongation during ICU care as well as the selection of appropriate drugs to prevent QT prolongation.

The CredibleMeds® list: Usage of QT interval prolonging drugs in Germany and discordances with prescribing information

AIMS

A substantial number of Summaries of Product Characteristics (SmPCs)/Prescribing Information (PI) have warnings or contraindications on QT interval prolongation. The goal of this work was to quantify usage of QT interval prolonging drugs according to the CredibleMeds^® database of the German outpatient drug prescription market and to evaluate discrepancies between German SmPCs/US PI and CredibleMeds^® .

METHODS

Drugs listed on CredibleMeds^® with known, possible or conditional risk for torsade de pointes were evaluated from 2000 to 2020. The German drug prescription report was used as source for defined daily dose- (DDD-) based prescriptions of the German outpatient drug prescription market of the public health insurance system. German SmPCs and US PI of 253 CredibleMeds^® -listed drugs were evaluated for contents regarding QT interval prolongation.

RESULTS

Of the drugs currently listed on CredibleMeds^® , 59.7% (95% confidence interval [CI] 53.5-65.5%) were listed after 2012. Due to newly listed drugs, the proportion of DDDs of CredibleMeds^® drugs among all prescriptions increased from 4.6% in 2013 to 21.1% in 2019. DDD-based usage of the CredibleMeds^® drugs already listed in 2013 was similar in 2019. Among the drugs with known QT risk according to CredibleMeds^® , 7.5% (95% CI 2.6-19.9%) of German SmPCs and 21.1% (95% CI 11.1-36.3%) of US PI had no mention of QT issues whatsoever.

CONCLUSION

A significant proportion of all drugs prescribed in the outpatient sector is associated with QT risks according to CredibleMeds^® . SmPCs and PI should systematically be evaluated for concordance with the widely used CredibleMeds^® database to increase medication safety.

Applying the Infectious Diseases Literature to People who Inject Drugs

People who inject drugs (PWID) presenting with injection drug use-associated infections are an understudied population excluded from most prospective infectious disease (ID) clinical trials. Careful application of the existing ID literature to PWID must consider their unique medical, psychological, and social challenges. Identification and treatment of the underlying substance use disorder are key underpinnings to any successful ID intervention.

Pharmacodynamic Drug-Drug interactions of QT-prolonging drugs in hospitalized psychiatric patients

At least 170 approved drugs are linked to QT prolongation, which can lead to serious adverse drug reactions (ADRs), such as Torsade de Pointes (TdP). The aim of this study was to analyze the prevalence and type of pharmacodynamic drug-drug interactions (DDIs) between QT-prolonging drugs in psychiatry. The present retrospective analysis used data from a large pharmacovigilance study, conducted in 10 psychiatric hospitals in Germany. Patients medication lists were screened for QT-prolonging drugs, classified according to the Arizona Center for Education and Research on Therapeutics (AZCERT). In total, 27,396 patient cases (46% female) with a mean (± standard deviation) age of 47 ± 18 years were included in the study. Altogether, 83% of the cases received at least one and up to eight QT-prolonging drugs at the same time. Combination of drugs with a known or possible risk for TdP (according to the AZCERT) was detected in 13,670 cases (50%). Most frequently prescribed psychotropic high-risk drugs (n = 48,995) were the antipsychotics pipamperone (n = 6202), quetiapine (n = 5718), prothipendyl (n = 4298), and risperidone (n = 4265). The replacement of high-risk drugs such as tricyclic antidepressants, levomepromazine, melperone, and promethazine with more tolerable drugs could avoid 11% of QT-prolonging drugs and increase the tolerability of psychopharmacological treatment. More than 80% of psychiatric patients receive at least one QT-prolonging drug during their hospital stay, and almost 50% of these drugs are combined in clinical practice. For the prevention of cardiac ADRs, the physician should evaluate the risk for QT prolongation for each drug and patient-specific risk factors before prescribing these drugs or drug combinations.

Risk of QTc prolongation among cancer patients treated with tyrosine kinase inhibitors

QTc interval prolongation can lead to life-threatening complications such as Torsade de Pointes (TdP), ventricular tachycardia (VT) and sudden cardiac death (SCD). It can occur with tyrosine kinase inhibitors (TKIs) but comparative real-world analyses on the incidence and complication rates are scarce. We retrospectively reviewed all cancer patients treated with TKI therapy at Mayo Clinic between January 2005 and December 2018 and had at least two ECGs (before and after TKI). For each TKI type, we determined the administration rate and incidence of QTc prolongation. QTc prolongation was defined as a corrected QT interval (by Fridericia formula) ≥450 ms in men and ≥470 ms in women. A total of 618 cancer patients were included with 902 TKI administrations, of which 654 (72.5%) were accounted for by pazopanib, sunitinib, imatinib, nilotinib and dasatinib. QTc prolongation (any grade) was reported in 28.8%, most commonly with nilotinib (38.7%) and dasatinib (41.7%). A QTc interval ≥500 ms and a QTc increase ≥60 ms was documented in 46 and 63 administrations, respectively. Life-threatening toxicity was seen in 14 cases (5.4% of QTc prolongation cases) including VT in 9, SCD in 3 and TdP in two administrations. The response to QTc prolongation was: discontinuation in 68%, dose reduction in 13.5%, temporary hold in 8.1% and no action in 10.4%. In conclusion, QTc prolongation with TKI therapy is very common (∼1/3 of cases) and in 5% (1.7% overall) associated with life-threatening complications. These data support recommendations for careful ECG monitoring in cancer patients undergoing TKI therapy.

Comparison of two algorithms to support medication surveillance for drug-drug interactions between QTc-prolonging drugs

BACKGROUND

QTc-prolongation is an independent risk factor for developing life-threatening arrhythmias. Risk management of drug-induced QTc-prolongation is complex and digital support tools could be of assistance. Bindraban et al. and Berger et al. developed two algorithms to identify patients at risk for QTc-prolongation.

OBJECTIVE

The main aim of this study was to compare the performances of these algorithms for managing QTc-prolonging drug-drug interactions (QT-DDIs).

MATERIALS AND METHODS

A retrospective data analysis was performed. A dataset was created from QT-DDI alerts generated for in- and outpatients at a general teaching hospital between November 2016 and March 2018. ECGs recorded within 7 days of the QT-DDI alert were collected. Main outcomes were the performance characteristics of both algorithms. QTc-intervals of > 500 ms on the first ECG after the alert were taken as outcome parameter, to which the performances were compared. Secondary outcome was the distribution of risk scores in the study cohort.

RESULTS

In total, 10,870 QT-DDI alerts of 4987 patients were included. ECGs were recorded in 26.2 % of the QT-DDI alerts. Application of the algorithms resulted in area under the ROC-curves of 0.81 (95 % CI 0.79-0.84) for Bindraban et al. and 0.73 (0.70-0.75) for Berger et al. Cut-off values of ≥ 3 and ≥ 6 led to sensitivities of 85.7 % and 89.1 %, and specificities of 60.8 % and 44.3 % respectively.

CONCLUSIONS

Both algorithms showed good discriminative abilities to identify patients at risk for QTc-prolongation when using ≥ 2 QTc-prolonging drugs. Implementation of digital algorithms in clinical decision support systems could support the risk management of QT-DDIs.

Managing drug-induced QT prolongation in clinical practice

Many drug therapies are associated with prolongation of the QT interval. This may increase the risk of Torsades de Pointes (TdP), a potentially life-threatening cardiac arrhythmia. As the QT interval varies with a change in heart rate, various formulae can adjust for this, producing a ‘corrected QT’ (QTc) value. Normal QTc intervals are typically <450 ms for men and <460 ms for women. For every 10 ms increase, there is a ~5% increase in the risk of arrhythmic events. When prescribing drugs associated with QT prolongation, three key factors should be considered: patient-related risk factors (eg, female sex, age >65 years, uncorrected electrolyte disturbances); the potential risk and degree of QT prolongation associated with the proposed drug; and co-prescribed medicines that could increase the risk of QT prolongation. To support clinicians, who are likely to prescribe such medicines in their daily practice, we developed a simple algorithm to help guide clinical management in patients who are at risk of QT prolongation/TdP, those exposed to QT-prolonging medication or have QT prolongation.

Development and validation of a tool to assess the risk of QT drug-drug interactions in clinical practice

BACKGROUND

The exact risk of developing QTc-prolongation when using a combination of QTc-prolonging drugs is still unknown, making it difficult to interpret these QT drug-drug interactions (QT-DDIs). A tool to identify high-risk patients is needed to support healthcare providers in handling automatically generated alerts in clinical practice. The main aim of this study was to develop and validate a tool to assess the risk of QT-DDIs in clinical practice.

METHODS

A model was developed based on risk factors associated with QTc-prolongation determined in a prospective study on QT-DDIs in a university medical center inthe Netherlands. The main outcome measure was QTc-prolongation defined as a QTc interval > 450 ms for males and > 470 ms for females. Risk points were assigned to risk factors based on their odds ratios. Additional risk factors were added based on a literature review. The ability of the model to predict QTc-prolongation was validated in an independent dataset obtained from a general teaching hospital against QTc-prolongation as measured by an ECG as the gold standard. Sensitivities, specificities, false omission rates, accuracy and Youden's index were calculated.

RESULTS

The model included age, gender, cardiac comorbidities, hypertension, diabetes mellitus, renal function, potassium levels, loop diuretics, and QTc-prolonging drugs as risk factors. Application of the model to the independent dataset resulted in an area under the ROC-curve of 0.54 (95% CI 0.51-0.56) when QTc-prolongation was defined as > 450/470 ms, and 0.59 (0.54-0.63) when QTc-prolongation was defined as > 500 ms. A cut-off value of 6 led to a sensitivity of 76.6 and 83.9% and a specificity of 28.5 and 27.5% respectively.

CONCLUSIONS

A clinical decision support tool with fair performance characteristics was developed. Optimization of this tool may aid in assessing the risk associated with QT-DDIs.

TRIAL REGISTRATION

No trial registration, MEC-2015-368.

Prevalence of QTc interval prolongation and its associated risk factors among psychiatric patients: a prospective observational study

BACKGROUND

QT interval prolongation is a growing concern worldwide, posing psychiatric patients to life-threatening fatal arrhythmias i.e., torsade de pointes. This study aimed to identify the prevalence of QT interval prolongation, its associated risk factors and prescribing patterns of QT prolonging drugs among psychiatric patients.

METHOD

A prospective observational study was conducted that included psychiatric patients from a tertiary care hospital and a psychiatry clinic in Peshawar, Khyber Pakhtunkhwa, Pakistan. Electrocardiogram was recorded of those patients who were using psychotropic medications for ≥7 days, aged 18 years or more, and of either gender, male or female. The Fredericia correction formula was used for measuring QTc values (corrected QT). Chi-square test was applied to estimate differences between patients with or without prolonged QTc interval whereas, logistic regression analysis was performed to identify various predictors of QT interval prolongation.

RESULTS

Out of 405 patients, the QTc interval was prolonged in 23 (5.7%) patients including 1 (0.2%) patient with highly abnormal prolonged QTc interval (> 500 ms). QT drugs (91.6%), female sex (38.7%) and hypertension (10.6%) were the most common QT prolonging risk factors. Prolonged QTc interval was significantly higher among male patients (p = 0.007).

CONCLUSION

In the present study, QT interval prolongation was observed in a considerable number of psychiatric patients. While, the high prevalence of QT prolonging risk factors among these patients warrants the increased risk of fatal arrhythmias. Therefore, risk assessment and electrocardiographic monitoring, and prescription of safer alternatives are highly recommended.

Predictive Validity of a QTc Interval Prolongation Risk Score in the Intensive Care Unit

BACKGROUND

Torsade de pointes is a form of polymorphic ventricular tachycardia associated with heart rate-corrected QT (QT_c ) interval prolongation. With approximately 24-61% of critically ill patients experiencing QT_c interval prolongation, a predictive tool to identify high-risk patients could assist in the monitoring and management in the intensive care unit (ICU). The Tisdale et al. Risk Score (TRS) is a predictive tool that was developed and validated in a cardiac critical care unit.

OBJECTIVES

The objective of this study was to evaluate the predictive validity (sensitivity and specificity) and likelihood ratios of the TRS in a medical ICU.

METHODS

This was a longitudinal, retrospective, cohort study of consecutive patients who met the inclusion criteria from October 2017 to June 2018 with a sample size of 264 patients. The sample size was derived based on the number of TRS covariates and an exploratory variable. Baseline characteristics and risk factors were documented from electronic health records. The first occurrence of QT_c interval prolongation, defined as a QT_c interval > 500 ms or an increase ≥ 60 ms above baseline, was the primary endpoint.

MAIN RESULTS

The sensitivity and specificity of the TRS for low-risk patients against the moderate-risk and high-risk patients were 97% (95% CI 91-99%) and 16% (95% CI 11-23%), respectively. These results corresponded to a positive likelihood ratio of 1.15 (95% CI 1.07-1.24) and a negative likelihood ratio of 0.20 (95% CI 0.06-0.65).

CONCLUSIONS

In conclusion, the TRS showed a high sensitivity, making it useful in identifying patients at risk of developing QT_c interval prolongation. Furthermore, patients categorized as low risk by the tool can be considered as having minimal risk of developing QT_c interval prolongation. Given the tool's low specificity, it does not reliably identify all patients at low risk of QT_c interval prolongation.

Plasma concentrations of antipsychotics and QTc prolongation: a pilot study

Background: Certain antipsychotics are known to cause QTc interval prolongation, which has been associated with increased risk of arrhythmia and sudden death. Previous studies have investigated whether there is an association between oral antipsychotic dose and QTc interval prolongation, however only few have examined the association between antipsychotic plasma concentrations and QTc interval.Material and methods: We performed a cross-sectional study with 22 forensic psychiatric in-patients. We measured the plasma concentration of the prescribed antipsychotics and performed an ECG simultaneously. We used Bazett's formula to calculate QTc and defined QTc as prolonged when: >460 ms for women and >450 ms for men.Results: Seventy-seven percent (n = 17) of the subjects were men (mean age = 40 years) and 91% (n = 20) were diagnosed with schizophrenia. QTc's ranged from 369 to 437 ms. Patients receiving QTc prolonging drugs had significantly greater QTc interval compared to patients receiving non-prolonging drugs. Weak to moderate negative correlations were found between QTc interval and both defined daily dose (DDD) and antipsychotic plasma concentration. There was no statistical difference between the correlations for DDD and plasma concentration versus QTc interval.Conclusion: We did not find a stronger association between antipsychotic plasma concentration and QTc than between antipsychotic dose and QTc. We suggest close monitoring with regular electroencephalogram's until the development of a better marker for predicting the risk of cardiac arrhythmia.

Identification of Risk of QT Prolongation by Pharmacists When Conducting Medication Reviews in Residential Aged Care Settings: A Missed Opportunity?

QT interval prolongation is associated with torsade de pointes and sudden cardiac death. QT prolongation can be caused by many drugs that are commonly prescribed in elderly residential aged care populations. The aim of this study was to investigate the prevalence of use of QT-prolonging drugs and to identify interventions made by pharmacists to reduce the risk of QT prolongation when conducting medication reviews in aged care. A retrospective analysis of 400 medication reviews undertaken by Australian pharmacists in aged care settings was conducted. The assessment included the risk of QT prolongation due to prescribed medications and other risk factors and the recommendations made by pharmacists to reduce the risk of QT prolongation. There was a high prevalence of the use of QT-prolonging medication, with 23% of residents (92 out of 400) taking at least one medication with a known risk of QT prolongation. Amongst the 945 prescribed drugs with any risk of QT prolongation, antipsychotics were the most common (n = 246, 26%), followed by antidepressants (19%) and proton pump inhibitors (13%). There appeared to be low awareness amongst the pharmacists regarding the risk of QT prolongation with drugs. Out of 400 reviews, 66 residents were categorised as high risk and were taking at least one medication associated with QT prolongation; yet pharmacists intervened in only six instances (9%), mostly when two QT-prolonging medications were prescribed. There is a need to increase awareness amongst pharmacists conducting medication reviews regarding the risk factors associated with QT prolongation, and further education is generally needed in this area.

QT prolongation in patients with acute leukemia or high-risk myelodysplastic syndrome prescribed antifungal prophylaxis during chemotherapy-induced neutropenia

Benefits of serial electrocardiographic (ECG) monitoring to detect QT prolongation in patients with hematological malignancies remain unclear. This retrospective, single-center, study evaluated 316 adult acute leukemia and high-risk MDS patients who received 11,775 patient-days of voriconazole prophylaxis during induction chemotherapy. Of these, 37 patients (16.2%) experienced QTc prolongation. Medications associated with QTc prolongation included furosemide, haloperidol, metronidazole, mirtazapine, prochlorperazine, and venlafaxine. Hypokalemia and hypomagnesemia were also significantly associated with QTc prolongation (HR 3.15; p = .003 and HR 6.47, p = .007, respectively). Management modifications due to QTc prolongation included discontinuation of QT prolonging medications (n = 25), more aggressive electrolyte repletion (n = 5), and enhanced ECG monitoring (n = 3). One patient with multiple QT prolonging factors experienced possible Torsades de Pointes. Overall mortality was 15% with no cardiac-related deaths. Serial ECG monitoring during induction chemotherapy can be tailored proportionally to QT-prolonging risk factors. Management should include aggressive electrolyte repletion and avoidance of concurrent QT prolonging medications.

[Antipsychotic pharmacotherapy for delirious syndromes - only temporary, symptom-oriented and considering QTc time]

BACKGROUND

QTc prolongation is a common and serious side effect of antipsychotics in the treatment of delirium. Nevertheless, the occurrence of ventricular tachycardia is rarely reported, so that the clinical relevance of a QTc prolongation triggered in this way remains unclear.

METHOD

The focus of this review is on the antipsychotic pharmacotherapy of delirium.

RESULTS AND CONCLUSIONS

In individual cases, before the prescription of an antipsychotic due to a delirium, a risk-benefit assessment must be made for the patient. For this purpose, patient and substance-specific risk factors for QTc prolongation must be checked and, if possible, reduced. A specific recommendation for an antipsychotic with assured low QTc interference can not be given because all antipsychotics for delirium treatment are potentially QTc-prolonging. Antipsychotic delirium treatment should be monitored, especially in patients with a high risk profile, for QTc prolongation by regular ECG controls.

Brazilian guidelines for the management of psychomotor agitation. Part 2. Pharmacological approach

Objective:

To present the essential guidelines for pharmacological management of patients with psychomotor agitation in Brazil.

Methods:

This is a systematic review of articles retrieved from the MEDLINE (PubMed), Cochrane Database of Systematic Reviews, and SciELO databases published from 1997 to 2017. Other relevant articles in the literature were also used to develop these guidelines. The search strategy used structured questions formulated using the PICO model, as recommended by the Guidelines Project of the Brazilian Medical Association. Recommendations were summarized according to their level of evidence, which was determined using the Oxford Centre for Evidence-based Medicine system and critical appraisal tools.

Results:

Of 5,362 articles retrieved, 1,731 abstracts were selected for further reading. The final sample included 74 articles that met all inclusion criteria. The evidence shows that pharmacologic treatment is indicated only after non-pharmacologic approaches have failed. The cause of the agitation, side effects of the medications, and contraindications must guide the medication choice. The oral route should be preferred for drug administration; IV administration must be avoided. All subjects must be monitored before and after medication administration.

Conclusion:

If non-pharmacological strategies fail, medications are needed to control agitation and violent behavior. Once medicated, the patient should be monitored until a tranquil state is possible without excessive sedation.

Systematic review registry number:

CRD42017054440.

Drug-drug interactions in breast cancer patients treated with CDK4/6 inhibitors

CDK4/6 inhibitors are a new class of anticancer drugs used for the treatment of women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced or metastatic breast cancer with disease progression following endocrine therapy. Polypharmacy is a well-known problem in advanced cancer causing potential drug-drug interactions (DDIs), which, in turn, may limit the therapeutic value of CDK4/6 inhibitors. Therefore, understanding the mechanisms underlying potential DDIs in patients taking CDK4/6 inhibitors may be useful in decision-making processes and represent an important step towards treatment personalization. The present review is aimed at describing the potential DDIs that might occur in breast cancer patients receiving CDK4/6 inhibitors based on direct evidence from the literature and mechanistic considerations tailored on specific class of drugs used in combination.

Identification of Patients At-Risk of QT Interval Prolongation during Medication Reviews: A Missed Opportunity?

The prolongation of the QT interval is a relatively rare but serious adverse drug reaction. It can lead to torsade de pointes, which is potentially life-threatening. The study’s objectives were: determine the use of QT interval-prolonging drugs in an elderly community-dwelling population at risk of medication misadventure and identify recommendations regarding the risk of QT interval prolongation made by pharmacists when performing medication reviews. In a retrospective evaluation, 500 medication review reports from Australian pharmacists were analysed. In patients taking at least one QT interval-prolonging drug, the individual risk of drug-induced QT interval prolongation was assessed. Recommendations of pharmacists to avoid the occurrence of this drug-related problem were examined. There was a high prevalence of use of potentially QT interval-prolonging drugs (71% patients), with 11% of patients taking at least one drug with a known risk. Pharmacists provided specific recommendations in only eight out of 35 patients (23%) with a high-risk score and taking drugs with known risk of QT interval prolongation. Pharmacists’ recommendations, when present, were focused on drugs with known risk of QT interval prolongation, rather than patients’ additional risk factors. There is a need to improve knowledge and awareness of this topic among pharmacists performing medication reviews.

A smart algorithm for the prevention and risk management of QTc prolongation based on the optimized RISQ-PATH model

AIMS

QTc prolongation is a complex problem linked with multiple risk factors. The RISQ-PATH score was previously developed to identify high-risk patients for QTc prolongation. The aim of this study was to optimize and validate this risk score in a large patient cohort, and to propose an algorithm to generate smart QT signals in the electronic medical record.

METHODS

A retrospective study was performed in the Nexus hospital network (n = 17) in Belgium. All electrocardiograms performed in 2015 in both ambulatory and hospitalized patients were collected together with risk factors for QTc prolongation (training database). Multiple logistic regression was performed to obtain the optimal prediction (RISQ-PATH) model. The model was tested in a validation database (electrocardiograms between January and April 2016).

RESULTS

In total, 60 208 patients (52.8% males, mean age 63 ± 18 years) were included; 3543 patients (5.9%) had a QTc ≥ 450(♂)/470(♀) ms and 453 (0.8%) a QTc ≥ 500 ms. The optimized RISQ-PATH model has an area under the ROC-curve of 0.772 [95% CI 0.763-0.780] to predict QTc ≥ 450(♂)/470(♀)ms. A predicted probability of ≥0.035 was set as cutoff for a high risk of QTc prolongation. This cutoff resulted in a sensitivity of 87.4% [95% CI 86.2-88.5] and a specificity of 46.2% [95% CI 45.8-46.6]. These results could be confirmed for QTc ≥ 500 ms and in the validation database (n = 28 400).

CONCLUSIONS

The RISQ-PATH model, with a cutoff probability of 0.035, predicted a prolonged QTc interval ≥ 450/470 ms or ≥500 ms with a sensitivity of ±87% and a specificity of ±45%. This RISQ-PATH model can be used in clinical decision support systems to create smart QT alerts.

Limited Evidence for Risk Factors for Proarrhythmia and Sudden Cardiac Death in Patients Using Antidepressants: Dutch Consensus on ECG Monitoring

Currently, there is a lack of international and national guidelines or consensus documents with specific recommendations for electrocardiogram (ECG) screening and monitoring during antidepressant treatment. To make a proper estimation of the risk of cardiac arrhythmias and sudden (cardiac) death during antidepressant use, both the drug and patient-specific factors should be taken into account; however, solid evidence on how this should be done in clinical practice is lacking. Available recommendations on the management of QT(c) prolongation (with antidepressant treatment) emphasize that special attention should be given to high-risk patients; however, clinicians are in need of more concrete suggestions about how to select patients for ECG screening and monitoring. Based on a review of the literature, a Dutch multidisciplinary expert panel aimed to formulate specific guidelines to identify patients at risk for cardiac arrhythmias and sudden death by developing a consensus statement regarding ECG screening before, and monitoring during, antidepressant use. We first reviewed the literature to identify the relative risks of various risk factors on cardiac arrhythmia and sudden (cardiac) death during antidepressant use. These relative contributions of risk factors could not be determined since no systematic reviews or meta-analyses quantitatively addressed this topic. Because evidence was insufficient, additional expert opinion was used to formulate recommendations. This resulted in readily applicable recommendations for clinical practice for selection of high-risk patients for ECG screening and monitoring. ECG screening and monitoring is recommended before and following the start of QTc-prolonging antidepressants in the presence of vulnerability to QTc prolongation or two or more risk factors (age > 65 years, female sex, concomitant use of a QTc-prolonging drug or concomitant use of a drug that influences the metabolism of a QTc-prolonging drug, cardiac disease, excessive dosing and specific electrolyte disturbances).

Incidence and outcomes of long QTc in acute medical admissions

AIMS

Prolonged QT interval on electrocardiogram (ECG) increases the risk of ventricular arrhythmia. Patients admitted to acute medical units (AMU) may be at risk of QT prolongation from multiple, recognised risk factors. Few data exist regarding incidence or outcomes of QT prolongation in acute general medical admissions. The aims were to determine the incidence of Bazett's-corrected QT (QTc) prolongation upon admission to AMU; the relationship between QTc and inpatient mortality, length of stay and readmission; proportion with prolonged QTc subsequently administered QT interval-prolonging drugs.

METHODS

Retrospective, observational study of 1000 consecutive patients admitted to an AMU in a large urban hospital.

EXCLUSION CRITERIA

age <18 years, ventricular pacing, poor quality/absent ECG. QTc determined manually from ECG obtained within 4-hours of admission. QTc prolongation considered ≥470 milliseconds (males) and ≥480 milliseconds (females). In both genders, >500 milliseconds was considered severe. Study end-points, (a) incidence of QTc prolongation at admission; (b) inpatient mortality, length of stay and readmission rates; (c) proportion with QTc prolongation subsequently administered QT interval-prolonging drugs.

RESULTS

Of 1000 patients, 288 patients were excluded, therefore final sample was n = 712. Patient age (mean ± SD) was 63.1 ± 19.4 years; females 49%. QTc prolongation was present in n = 50 (7%) at admission; 1.7% had QTc interval >500 ms. Of the 50 patients admitted with prolonged QTc, 6 (12%) were subsequently administered QT interval-prolonging drugs. QTc prolongation was not associated with worse inpatient mortality or readmission rate. Length of stay was greater in those with prolonged QTc, 7.2 (IQR 2.4-13.2) days vs 3.3 (IQR 1.3-10.0; P = 0.004), however, in a regression model, presence of QTc did not independently affect length of stay.

CONCLUSIONS

QTc interval prolongation is frequent among patients admitted to AMU. QT interval-prolonging drugs are commonly prescribed to patients presenting with prolonged QTc but whether this affects clinical outcomes is uncertain.

Moxifloxacin-induced QT interval prolongation and torsades de pointes: a narrative review

INTRODUCTION

Moxifloxacin is widely used for the treatment of a number of infectious diseases because of its favorable pharmacological profile and high clinical success rate. However, it is often criticized for its higher risk of QTc interval prolongation (QTIP) and torsades de pointes (TdP).

AREAS COVERED

A review of published literature on moxifloxacin-related QTIP and TdP. Readers will be provided with a comprehensive overview of the prevalence, cellular mechanism, risk factors, and magnitude of QTIP of moxifloxacin.

EXPERT OPINION

In healthy subjects, moxifloxacin prolongs the QTc interval by 11.5-19.5 ms, it binds at the Tyr652 residue in the S6 pore domain of the human ether a-go-go gene related potassium channel. Considerable QTIP (30-60 ms) have also been reported in some patients, for instance the incidence of QTIP (30-60 ms) in elderly pneumonia patients was 15.5%. Moxifloxacin-induced QTIP may be of little clinical importance in healthy individuals. However, marked QTIP (>60 ms) and TdP have been reported in high-risk patients (patients who have multiple QT prolonging risk factors). Patients must be thoroughly assessed prior to the use of moxifloxacin and high-risk patients must be identified using risk assessment tools to ensure safe use of moxifloxacin and to safeguard patients' health.

Risk Management of Hospitalized Psychiatric Patients Taking Multiple QTc-Prolonging Drugs

PURPOSE/BACKGROUND

Drug-related QTc prolongation has been linked with Torsade de Pointes and sudden cardiac death. The objective of this study was to investigate the impact of starting an additional QTc-prolonging drug on the QTc interval of psychiatric inpatients.

METHODS

An observational study was performed between May 2011 and December 2014 in 6 Belgian psychiatric hospitals. Inpatients who were already taking 1 QTc-prolonging drug or more could be included in the study when an additional QTc-prolonging drug was started. Electrocardiograms were performed at baseline and follow-up. Demographic, medical, medication, and laboratory data were collected. A risk score was used to estimate the risk of QTc prolongation based on patient-specific risk factors. A cutoff value of 8 points was set as high risk for QTc prolongation.

RESULTS

One hundred fifty-two patients (44.7% women; mean age, 44 [SD, 17] years) were included who received a prescription for an additional QTc-prolonging drug. There was a small but significant difference (P = 0.032) in mean QTc interval between baseline (409.1 [SD, 21.8] milliseconds) and follow-up (411.8 [SD, 21.7] milliseconds). Three patients developed a prolonged QTc interval in the follow-up electrocardiogram (QTc, ≥450 [men]/470 [women] milliseconds); 8 patients had a delta QTc of 30 milliseconds or longer. No cases of torsade de pointes or sudden cardiac death were identified. Fifty-eight patients (38.2%) had a risk score of 8 or higher; these patients had a significantly longer QTc interval at follow-up than did patients with a risk score of lower than 8 (P < 0.001).

IMPLICATIONS/CONCLUSIONS

Only a limited number of patients developed a prolonged QTc interval after the start of an additional QTc-prolonging drug. Nevertheless, it is still important to screen for high-risk patients at baseline. A risk score can help to select high-risk patients and to stimulate an appropriate and feasible risk management of QTc prolongation in psychiatry.

QT interval prolongation in hospitalized patients on cardiology wards: a prospective observational study

PURPOSE

Prolonged QT interval may lead to a lethal form of arrhythmia, torsades de pointes (TdP), which is associated with cardiovascular mortality. Therefore, we aimed to identify prevalence of QT interval prolongation, compare clinical characteristics of patients with normal and prolonged QT interval, and identify predictors of QT interval prolongation.

METHODS

A prospective observational study was conducted in cardiology wards of two teaching hospitals in Pakistan. Bazett's correction formula was used for the calculation of QTc interval. Prevalence of QT prolongation and pro-QTc scores were calculated. Comparative analysis was performed with respect to various clinical characteristics by applying t test and chi-square test. Odds ratios were calculated using regression analysis.

RESULTS

Among 417 patients, 44.6% were found having prolonged QT interval, of which, 17.3% presented with an abnormally high QTc interval (> 500 ms). Significant difference was recorded between the groups (normal vs. prolonged) with respect to age, all prescribed medications, QT drugs, number of risk factors, QT-DDIs (QT-prolonging drug-drug interactions), gender, and diuretics use. Multivariate logistic regression analysis showed significant results for various predictors such as male gender (p = 0.03), various age categories 41-50 years (p = 0.04), 51-60 years (p = 0.01), and > 60 years (p < 0.001), and diuretics (p = 0.008).

CONCLUSION

A substantial number of patients in cardiology wards presented with QT prolongation. Proper considerations are needed in order to minimize the associated risk particularly in patients with abnormally high QT prolongation, old age, polypharmacy, one or more QT-prolonging drugs, and high pro-QTc scores.

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.