Drugs that cause Torsades de pointes and increase the risk of sudden cardiac death

Meta-analysis on outcome-worsening comorbidities of COVID-19 and related potential drug-drug interactions

Drug-drug interactions (DDI) potentially occurring between medications used in the course of COVID-19 infection and medications prescribed for the management of underlying comorbidities may cause adverse drug reactions (ADRs) contributing to worsening of the clinical outcome in affected patients. First, we conducted a meta-analysis to determine comorbidities observed in the course of COVID-19 disease associated with an increased risk of worsened clinical outcome from 24 published studies. In addition, the potential risk of DDI between medications used in the course of COVID-19 treatment in these studies and those for the management of observed comorbidities was evaluated for possible worsening of the clinical outcome. Our meta-analysis revealed an implication cardiometabolic syndrome (e.g. cardiovascular disease, cerebrovascular disease, hypertension, and diabetes), chronic kidney disease and chronic obstructive pulmonary disease as main co-morbidities associated with worsen the clinical outcomes including mortality (risk difference RD 0.12, 95 %-CI 0.05-0.19, p = 0.001), admission to ICU (RD 0.10, 95 %-CI 0.04-0.16, p = 0.001) and severe infection (RD 0.05, 95 %-CI 0.01-0.09, p = 0.01) in COVID-19 patients. Potential DDI on pharmacokinetic level were identified between the antiviral agents atazanavir and lopinavir/ritonavir and some drugs, used in the treatment of cardiovascular diseases such as antiarrhythmics and anti-coagulants possibly affecting the clinical outcome including cardiac injury or arrest because of QTc-time prolongation or bleeding. Concluding, DDI occurring in the course of anti-Covid-19 treatment and co-morbidities could lead to ADRs, increasing the risk of hospitalization, prolonged time to recovery or death on extreme cases. COVID-19 patients with cardiometabolic diseases, chronic kidney disease and chronic obstructive pulmonary disease should be subjected to particular carefully clinical monitoring of adverse events with a possibility of dose adjustment when necessary.

Current status of histone deacetylase inhibitors in cutaneous T-cell lymphoma

Cutaneous T cell lymphoma (CTCL) is a non-Hodgkin's lymphoma with a heterogenous presentation and highly variable disease course. The most common subtypes of CTCL are mycosis fungoides (MF) and Sézary Syndrome (SS). Treatment varies based on the stage of the disease with skin directed therapies typically utilized for early stage disease, and systemic therapies employed for more advanced disease. There are few highly effective treatments available, and systemic therapies have limited response rates. Histone deacetylase inhibitors have emerged as mainstream treatments for MF/SS over the past several years. Here, we discuss the mechanism of action of histone deacetylase inhibitors in relation to the pathogenesis of MF/SS, evaluate the clinical trials that led to Food and Drug Administration approval of two of the histone deacetylase inhibitors for MF/SS and describe the results for those still under investigation. Additionally, we discuss the potential for combination therapies in order to optimize outcomes of treatment with histone deacetylase inhibitors.

Current Status of HDAC Inhibitors in Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of lymphomas that are characterized by primary skin involvement. Mycosis fungoides (MF) and Sézary syndrome (SS), the two most common subtypes of CTCL, can be difficult to manage clinically as there are few effective treatment options available. Recently, histone deacetylase inhibitors (HDACi) have emerged as promising therapies with favorable adverse effect profiles, compared with traditional chemotherapies. In this article, we review the published literature to evaluate the role of HDACi in the treatment of CTCL. Specifically, we (1) briefly discuss the molecular rationale for the use of HDACi in CTCL; (2) compare the efficacy, tolerability, and adverse effects of HDACi; (3) review the cardiac safety data; and (4) discuss optimization of therapy with HDACi in the treatment of CTCL.

The role of concentration-effect relationships in the assessment of QTc interval prolongation

Population pharmacokinetic and pharmacokinetic-pharmacodynamic (PKPD) modelling has been widely used in clinical research. Yet, its application in the evaluation of cardiovascular safety remains limited, particularly in the evaluation of pro-arrhythmic effects. Here we discuss the advantages of disadvantages of population PKPD modelling and simulation, a paradigm built around the knowledge of the concentration-effect relationship as the basis for decision making in drug development and its utility as a guide to drug safety. A wide-ranging review of the literature was performed on the experimental protocols currently used to characterize the potential for QT interval prolongation, both pre-clinically and clinically. Focus was given to the role of modelling and simulation for design optimization and subsequent analysis and interpretation of the data, discriminating drug from system specific properties. Cardiovascular safety remains one of the major sources of attrition in drug development with stringent regulatory requirements. However, despite the myriad of tests, data are not integrated systematically to ensure accurate translation of the observed drug effects in clinically relevant conditions. The thorough QT study addresses a critical regulatory question but does not necessarily reflect knowledge of the underlying pharmacology and has limitations in its ability to address fundamental clinical questions. It is also prone to issues of multiplicity. Population approaches offer a paradigm for the evaluation of drug safety built around the knowledge of the concentration-effect relationship. It enables quantitative assessment of the probability of QTc interval prolongation in patients, providing better guidance to regulatory labelling and understanding of benefit/risk in specific populations.

Effect of single doses of IV palonosetron, up to 2.25 mg, on the QTc interval duration: a double-blind, randomized, parallel group study in healthy volunteers

PURPOSE

The use of serotonin type 3 (5-HT3) receptor antagonists (RAs) in the prevention of nausea and vomiting caused by emetogenic chemotherapy is part of a comprehensive management strategy for patients undergoing chemotherapy. Electrocardiographic effects have been reported in patients after intravenous administration of 5-HT3 RAs. The present study investigated the electrocardiogram (ECG) profile of the 5-HT3 RA palonosetron following International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) E14 Guidelines.

METHODS

A total of 221 healthy subjects (101 females, 120 males) were randomized in this phase I, double-blind, double-dummy, parallel group study and assigned to one of five treatments: placebo, palonosetron (0.25, 0.75, or 2.25 mg), or moxifloxacin (400 mg). ECGs were recorded for 24 h pre-dosing until 48 h post-dose. The primary endpoint was the placebo time-matched and baseline-subtracted individual QTc interval prolongation (ΔΔQTcI).

RESULTS

The QTc interval was not prolonged after administration of palonosetron (ΔΔQTcI upper confidence interval was <10 ms for all time points in all palonosetron treatment groups). Assay sensitivity was confirmed with the expected change in the QTc interval after administration of the positive control moxifloxacin.

CONCLUSIONS

Palonosetron, even at supratherapeutic doses, has no effect on cardiac repolarization as measured by the QTc interval in a validated controlled clinical trial.

Histone deacetylase inhibitors in hematological malignancies and solid tumors

Histone deacetylase (HDAC) inhibitors are emerging as promising anticancer drugs. Because aberrant activity and expression of HDACs have been implicated in various cancer types, a wide range of HDAC inhibitors are being investigated as anticancer agents. Furthermore, due to the demonstrable anticancer activity in both in vitro and in vivo studies, numerous HDAC inhibitors have undergone a rapid phase of clinical development in various cancer types, either as a monotherapy or in combination with other anticancer agents. Although preclinical trials show that HDAC inhibitors have a variety of biological effects across multiple pathways, including regulation of gene expression, inducing apoptosis and cell cycle arrest, inhibiting angiogenesis, and regulation of DNA damage and repair, the mechanism by which the clinical activity is mediated remains unclear. Understanding the mechanisms of anticancer activity of HDAC inhibitors is essential not only for rational drug design for targeted therapies, but for the design of optimized clinical protocols. This paper describes the links between HDACs and cancer, and the underlying mechanisms of action of HDAC inhibitors against hematological malignancies and solid tumors. Further, this review presents the clinical outcomes of vorinostat, romidepsin, and belinostat, which are approved by the United States Food and Drug Administration for the treatment of lymphomas.

Ventricular dysrhythmias associated with poisoning and drug overdose: a 10-year review of statewide poison control center data from California

BACKGROUND

Ventricular dysrhythmias are a serious consequence associated with drug overdose and chemical poisoning. The risk factors for the type of ventricular dysrhythmia and the outcomes by drug class are not well documented.

OBJECTIVE

The aim of this study was to determine the most common drugs and chemicals associated with ventricular dysrhythmias and their outcomes.

METHODS

We reviewed all human exposures reported to a statewide poison control system between 2002 and 2011 that had a documented ventricular dysrhythmia. Cases were differentiated into two groups by type of arrhythmia: (1) ventricular fibrillation and/or tachycardia (VT/VF); and (2) torsade de pointes (TdP).

RESULTS

Among the 300 potential cases identified, 148 cases met the inclusion criteria. Of these, 132 cases (89%) experienced an episode of VT or VF, while the remaining 16 cases (11%) had an episode of TdP. The most commonly involved therapeutic classes of drugs associated with VT/VF were antidepressants (33/132, 25%), stimulants (33/132, 25%), and diphenhydramine (16/132, 12.1%). Those associated with TdP were antidepressants (4/16, 25%), methadone (4/16, 25%), and antiarrhythmics (3/16, 18.75%). Drug exposures with the greatest risk of death in association with VT/VF were antidepressant exposure [odds ratio (OR) 1.71; 95% confidence interval (CI) 0.705-4.181] and antiarrhythmic exposure (OR 1.75; 95% CI 0.304-10.05), but neither association was statistically significant. Drug exposures with a statistically significant risk for TdP included methadone and antiarrhythmic drugs.

CONCLUSIONS

Antidepressants and stimulants were the most common drugs associated with ventricular dysrhythmias. Patients with suspected poisonings by medications with a high risk of ventricular dysrhythmia warrant prompt ECG monitoring.

Not-in-trial simulation I: Bridging cardiovascular risk from clinical trials to real-life conditions

AIMS

The assessment of heart rate-corrected QT (QTc) interval prolongation relies on the evidence of drug effects in healthy subjects. This study demonstrates the relevance of pharmacokinetic-pharmacodynamic (PKPD) relationships to characterize drug-induced QTc interval prolongation and explore the discrepancies between clinical trials and real-life conditions.

METHODS

d,l-Sotalol data from healthy subjects and from the Rotterdam Study cohort were used to assess treatment response in a phase I setting and in a real-life conditions, respectively. Using modelling and simulation, drug effects at therapeutic doses were predicted in both populations.

RESULTS

Inclusion criteria were shown to restrict the representativeness of the trial population in comparison to real-life conditions. A significant part of the typical patient population was excluded from trials due to weight and baseline QTc interval criteria. Relative risk was significantly different between sotalol users with and without heart failure, hypertension, diabetes and myocardial infarction (P < 0.01). Although drug effects do cause an increase in the relative risk of QTc interval prolongation, the presence of diabetes represented an increase from 4.0 [95% confidence interval (CI) 2.7-5.8] to 6.5 (95% CI 1.6-27.1), whilst for myocardial infarction it increased from 3.4 (95% CI 2.3-5.13) to 15.5 (95% CI 4.9-49.3).

CONCLUSIONS

Our findings show that drug effects on QTc interval do not explain the observed QTc values in the population. The prevalence of high QTc values in the real-life population can be assigned to co-morbidities and concomitant medications. These findings substantiate the need to account for these factors when evaluating the cardiovascular risk of medicinal products.

Targeted cancer therapy: giving histone deacetylase inhibitors all they need to succeed

Histone deacetylase inhibitors (HDACis) have now emerged as a powerful new class of small-molecule therapeutics acting through the regulation of the acetylation states of histone proteins (a form of epigenetic modulation) and other non-histone protein targets. Over 490 clinical trials have been initiated in the last 10 years, culminating in the approval of two structurally distinct HDACis - SAHA (vorinostat, Zolinza™) and FK228 (romidepsin, Istodax™). However, the current HDACis have serious limitations, including ineffectively low concentrations in solid tumors and cardiac toxicity, which is hindering their progress in the clinic. Herein, we review the primary paradigms being pursued to overcome these hindrances, including HDAC isoform selectivity, localized administration, and targeting cap groups to achieve selective tissue and cell type distribution.

Biweekly rituximab, cyclophosphamide, vincristine, non-pegylated liposome-encapsulated doxorubicin and prednisone (R-COMP-14) in elderly patients with poor-risk diffuse large B-cell lymphoma and moderate to high 'life threat' impact cardiopathy

This Phase II study assessed feasibility and efficacy of a biweekly R-COMP-14 regimen (rituximab, cyclophosphamide, non-pegylated liposome-encapsulated doxorubicin, vincristine and prednisone) in untreated elderly patients with poor-risk diffuse large B-cell lymphoma (DLBCL) and moderate to high ‘life threat’ impact NIA/NCI cardiac comorbidity. A total of 208 courses were delivered, with close cardiac monitoring, to 41 patients (median age: 73 years, range: 62–82; 37% >75 years) at a median interval of 15·6 (range, 13–29) days; 67% completed all six scheduled courses. Response rate was 73%, with 68% complete responses (CR); 4-year disease-free survival (DFS) and time to treatment failure (TTF) were 72% and 49%, respectively. Failures were due to early death (n = 3), therapy discontinuations (no-response n = 2; toxicity n = 6), relapse (n = 6) and death in CR (n = 3). Incidence of cardiac grade 3–5 adverse events was 7/41 (17%; 95% confidence interval: 8–31%). Time to progression and overall survival at 4-years were 77% and 67%, respectively. The Age-adjusted Charlson Comorbidity Index (aaCCI) correlated with failures (P = 0·007) with patients scoring ≤7 having a longer TTF (66% vs. 29%; P = 0·009). R-COMP-14 is feasible and ensures a substantial DFS to poor-risk DLBCL patients who would have been denied anthracycline-based treatment due to cardiac morbidity. The aaCCI predicted both treatment discontinuation rate and TTF.

Inflammatory factors that contribute to upregulation of ERG and cardiac arrhythmias are suppressed by CPU86017, a class III antiarrhythmic agent

The aim of this study was to verify whether exaggerated arrhythmogenesis is attributed to inflammatory factors actively involving an excess of reactive oxygen species (ROS), transforming growth factor (TGF)-beta and endothelin (ET). We hypothesized that CPU86017, derived from berberine, which possesses multi-channel blocking activity, could suppress inflammatory factors, resulting in inhibition of over-expression of ether-a-go-go (ERG) and an augmented incidence of ventricular fibrillation (VF) in ischaemia/reperfusion (I/R). Rats with cardiomyopathy (CMP) induced by thyroxine (0.2 mg(-1)kg(-1) s.c. daily for 10 days) were treated with propranolol (10 mgkg(-1) p.o.) or CPU86017 (80 mgkg(-1) p.o.) on days 6-10. On the 11th day, arrhythmogenesis of the CMP was evaluated by I/R. In the CMP control group, an increase in VF incidence was found with the I/R episode, accompanied by increased ROS, which manifested as an increased level of malondialdehyde and decreased activities of SOD, glutathione peroxidase and catalase in the myocardium. Levels of inducible nitric oxide synthase and TGF-beta mRNA were increased in association with upregulation of preproET-1 and ET-converting enzyme. We found increased levels of ERG, which correlated well with arrhythmogenesis. Treatment with CPU86017 or propranolol reversed these changes. These experiments verified our hypothesis that the inflammatory factors ROS, iNOS, TGF-beta and ET-1 are actively involved in upregulation of ERG and arrhythmogenesis. CPU86017 and propranolol reduced VF by suppressing these inflammatory factors in the myocardium.

Comparison of the QT interval response during sinus and paced rhythm in conscious and anesthetized beagle dogs

INTRODUCTION

The aim of the present study was to compare sensitivity in detecting the drug-induced QT interval prolongation in three dog models: conscious telemetered at sinus rhythm and conscious and anesthetized dogs during atrial pacing. The test substances used represent different chemical classes with different pharmacological and pharmacokinetic profiles.

METHOD

Dofetilide and moxifloxacin were tested in all models, whereas cisapride and terfenadine were tested in the conscious telemetered and paced models. All substances were given as two consecutive 1.5-h intravenous infusions (infusions 1 and 2). The individual concentration-time courses of dofetilide, moxifloxacin, and cisapride were linked to the drug-induced effects on the QT interval and described with a pharmacokinetic-pharmacodynamic model to obtain an estimate of the unbound plasma concentrations at steady state that give a 10- and 20-ms drug-induced QT interval prolongation (CE10ms and CE20ms).

RESULTS

In the conscious telemetered, conscious paced, and anesthetized dog models, the mean CE10ms values were 1.4, 4.0, and 2.5 nM for dofetilide and 1300, 1800, and 12,200 nM for moxifloxacin. For cisapride, the CE10ms values were 8.0 and 4.4 nM in the conscious telemetered and conscious paced dog models. The drug-induced QT interval prolongation during the last 30 min of infusions 1 and 2 was comparable in the conscious models, but smaller in the anesthetized dog model. Terfenadine displayed a marked delay in onset of response, which could only be detected by the extended ECG recording.

DISCUSSION

All dog models investigated detected QT interval prolongation after administration of the investigated test substances with similar sensitivity, except for a lower sensitivity in the anesthetized dogs following moxifloxacin administration. The conscious telemetered dog model was favorable, mainly due to the extended continuous ECG recording, which facilitated detection and quantification of delayed temporal differences between systemic exposure and drug-induced QT interval prolongation.

Evidence-based review of the black-box warning for droperidol

PURPOSE

Data collected from the Food and Drug Administration (FDA) under the Freedom of Information Act are presented to help clinicians understand the data prompting the black-box warning for droperidol and to make educated decisions regarding the use of droperidol and alternative agents.

SUMMARY

A written request was submitted to FDA to provide a report of any and all reports of cardiovascular adverse events related to droperidol that were part of the decision to add a black-box warning to the label of droperidol. The report listed 277 cases of adverse effects associated with droperidol since its introduction to the market in 1970. Many of the reports were duplicates, leaving a total of 65 individual cases. Of these cases, only 2 described adverse effects possibly caused by droperidol in dosages commonly used in the United States. In addition to these reports, the results of two European studies prompted FDA to make the decision for the black-box warning. Both studies used droperidol doses 50-100 times higher than those used in the United States.

CONCLUSION

Studies show that there is a dose-dependent increase in the rate of adverse cardiovascular events when droperidol is used either alone or in combination with other medications that cause Q-T interval prolongation. At this time, there does not appear to be significant evidence to suggest that serotonin type 3-receptor (5-HT(3)) antagonists are safer than droperidol with regard to Q-T interval prolongation. More studies are needed to determine the safety and efficacy of droperidol when used in doses of 0.625-1.25 mg compared with the 5-HT(3) antagonists.

Hypokalemia, cardiac failure, and reporting NXY-059 safety for acute stroke

NXY-059, an alpha-phenyl-N-tert-butyl nitrone derivative, is a free radical-trapping agent presently in late clinical trials as a potential neuroprotectant limiting reperfusion injury following acute stroke. Two recent trials suggest that NXY-059 causes hypokalemia and associated cardiac disturbances. With regard to the mechanism of such association, most investigators agree that potent trapping of free radicals leads to the 11 beta-hydroxysteroid dehydrogenase blockade in kidneys, diminishing renal hydrocortisone oxidation and increasing K(+) ion urine excretion. Importantly, potassium deficiency represents the major avoidable cause of the array of serious cardiac adverse reactions: QT-prolongation, Torsades de pointes and other life-threatening arrhythmias, and higher risks for perioperative cardiopulmonary resuscitation and cardiac death. Because a prime target for NXY-059 use will likely be acute strokes in the emergency room environment, the potential combination of the drug with intensive therapy including fluid infusions, particularly with diuretics, might be especially harmful because of the synergic depletion of potassium, which might also jeopardize the fate of the novel nitrone neuroprotectant.

Priorities and standards in pharmacogenetic research

The current enthusiasm for pharmacogenetics draws much of its inspiration from the relatively few examples of polymorphisms that have marked and seemingly clinically relevant effects on drug response. In this regard, pharmacogenetic research has paralleled the study of human disease, which has enjoyed success in identifying mutations underlying mendelian conditions. Progress in deciphering the genetics of complex diseases, involving the interaction of multiple genes with each other and with the environment has been considerably less successful. In most instances, drug responses will probably also prove to be complex, influenced by both the environment and multiple genetic factors. For pharmacogenetics to deliver on its potential, this complexity will need to be recognized and accommodated, both in basic research and in clinical application of pharmacogenetics. As the attention of researchers begins to shift toward more systematic pharmacogenetic investigations, we suggest some priorities and standards for pharmacogenetic research.

Electrocardiographic predictors of cardiovascular outcome in women: the National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) study

OBJECTIVES

We sought to analyze the value of infrequently measured parameters of the 12-lead electrocardiogram (ECG) in predicting cardiovascular events in women with suspected myocardial ischemia who were referred for cardiac catheterization.

BACKGROUND

Routinely analyzed ECG parameters have low predictive value for cardiovascular events in women with preserved left ventricular function and suspected myocardial ischemia. The predictive value of ECG parameters for cardiovascular disease has not been fully determined.

METHODS

Women enrolled in the National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) study who had complete digital 12-lead ECG and quantitative angiography data were studied. Clinical and ECG predictors of cardiovascular disease events, defined as death, congestive heart failure, and non-fatal myocardial infarction, were determined.

RESULTS

Of 143 women with ECG and angiographic data (mean age 59 +/- 13 years, left ventricular ejection fraction 64.1 +/- 8.6%), 13% had events during a mean follow-up period of 3.3 +/- 1.6 years. Independent predictors of event occurrences included a wider QRS-T angle (i.e., the spatial electrical angle between the QRS complex and the T-wave; p = 0.0005), wider QRS complex (p = 0.004), longer QTrr (i.e., age- and gender-adjusted QT interval; p = 0.0004), a more depressed ST-segment in precordial lead V5 (p = 0.0002), and a higher coronary artery disease severity score (p = 0.02).

CONCLUSIONS

Several 12-lead ECG parameters, such as the QRS-T angle and the QRS and QTrr duration, are predictive of future cardiovascular events in women with suspected myocardial ischemia.