Divergent electrophysiologic profile of fluconazole and voriconazole in an experimental whole-heart model of proarrhythmia

Cardiac arrhythmias of BCR-ABL inhibitors with or without triazole antifungal agents: A real-world pharmacovigilance study based on the food and drug administration adverse event reporting system database

Objectives

Breakpoint Cluster Region (BCR)-Abelson tyrosine kinase (ABL) inhibitors are widely used in the treatment of blood cancers, particularly chronic myelogenous leukemia and are often combined with triazole antifungal agents to prevent fungal infections. However, the cardiac arrhythmia risks associated with BCR-ABL inhibitors in combination with triazole antifungal agents in real-world settings remain poorly understood. To address this gap, we conducted a pharmacovigilance study to evaluate and compare the cardiac arrhythmia profiles of BCR-ABL inhibitors when used with and without triazole antifungal agents in clinical practice.

Methods

A disproportionality analysis was performed using the Food and Drug Administration Adverse Event Reporting System database (2004Q1-2024Q2). To identify potential signals of cardiac arrhythmias associated with BCR-ABL inhibitors, with or without triazole antifungal agents, we calculated reporting odds ratios and 95% confidence intervals. Comparisons were made between BCR-ABL inhibitor monotherapy and all other drugs in the Food and Drug Administration Adverse Event Reporting System database, as well as between BCR-ABL inhibitors combined with triazole antifungal agents and BCR-ABL inhibitor monotherapy. Additionally, the Weibull shape parameter test was also used to evaluate time-to-onset.

Results

From 2004Q1 to 2024Q2, the Food and Drug Administration Adverse Event Reporting System database reported 21,433,114 cases, including 2666 and 68 cases of cardiac arrhythmias linked to BCR-ABL inhibitor monotherapy and its combination with triazole antifungal agents, respectively. The reporting odds ratios and their 95% confidence intervals for BCR-ABL inhibitor monotherapy, asciminib, nilotinib, and ponatinib were 1.31 (1.27-1.36), 2.11 (1.45-3.06), 2.66 (2.53-2.80), and 1.18 (1.05-1.33), respectively. Dasatinib plus triazole antifungal agents (reporting odds ratio: 2.98, 95% CI: 1.93-4.60) and ponatinib plus triazole antifungal agents (reporting odds ratio: 1.53, 95% CI: 1.08-2.16) were associated with a higher disproportionality of cardiac arrhythmias than BCR-ABL inhibitor monotherapy. The median time-to-onset was longer with monotherapy than with BCR-ABL inhibitors plus triazole antifungal agents (2.63 vs. 0.34 months, p < 0.001), both indicating an early failure type.

Conclusions

BCR-ABL inhibitors plus triazole antifungal agents increase the risk of cardiac arrhythmia, particularly in the early stages of treatment, with the risk decreasing over time.

Calculated parenteral initial therapy of bacterial infections: Antibiotic treatment in the elderly

This is the fifteenth chapter of the guideline “Calculated initial parenteral treatment of bacterial infections in adults – update 2018” in the 2^nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience.

Multimorbidity, an atypical symptomatology of infections in combination with multimedication, the associated interaction risks and serious consequences of synergistic side effects characterize the conditions when deciding on the use of antibiotics in old age. Strict decision regarding the indication itself, choice of the best antibiotic even considering rare side effects which may be dangerous in the elderly, determining the correct dose, dosing interval and the shortest possible duration according to the physiological status of the patient as well as monitoring effectiveness and toxicity detect expected and unexpected side effects early. Recommendations must reflect the peculiarities of antibiotic treatment in elderly patients.

Additive Proarrhythmic Effect of Combined Treatment with QT-Prolonging Agents

Drug combinations may elevate the risk of proarrhythmia. The aim of the present study was to investigate whether combinations of non-cardiovascular agents induce an additive increase in the proarrhythmic risk. In 12 female rabbit hearts, a drug combination of cotrimoxazole (300 µM), ondansetron (5 µM) and domperidone (1 µM) was infused after obtaining baseline data. In another 13 hearts, a combination of cotrimoxazole (300 µM), ondansetron (5 µM) and erythromycin (300 µM) was infused. Monophasic action potentials and ECG displayed a significant QT prolongation in all groups. This was accompanied by a significant increase in action potential duration. Of note, addition of each drug resulted in a further increase in the QT interval. Furthermore, a significant elevation of spatial dispersion of repolarization was observed. Lowering of potassium concentration in bradycardic AV-blocked hearts provoked early afterdepolarizations and torsade de pointes (TDP) in both study groups. Under baseline conditions, no episodes of TDP recorded. After administration of the first agent, TDP occurred in 5 of 12 hearts (37 episodes) and 5 of 13 hearts (26 episodes), respectively. After additional infusion of the second drug, TDP were recorded in 7 of 12 hearts (55 episodes) and 8 of 13 hearts (111 episodes). After additional infusion of the third drug, TDP occurred in 11 of 12 hearts (118 episodes) and 9 of 13 hearts (88 episodes). Combined treatment with several non-cardiovascular QT-prolonging agents resulted in a remarkable occurrence of proarrhythmia. An additive and significant prolongation of cardiac repolarization combined with an increased spatial dispersion of repolarization represents the underlying electrophysiological mechanism.

Severe Proarrhythmic Potential of the Antiemetic Agents Ondansetron and Domperidone

The potential of ondansetron and domperidone, both clinically established antiemetic agents, to increase the QT-interval has been described in several case reports. Therefore, the aim of the present study was to investigate whether these drugs may provoke polymorphic ventricular tachycardia in a sensitive experimental model of drug-induced proarrhythmia. In 10 female rabbits, ondansetron (1, 5 and 10 µM, n = 10) or domperidone (0.5, 1 and 2 µM, n = 8) was infused after obtaining baseline data. Eight endo- and epicardial monophasic action potentials and a simultaneously recorded 12-lead ECG reproduced the clinically observed QT-prolongation (ondansetron: 1 µM:+17 ms, 5 µM:+41 ms, 10 µM:+78 ms, p < 0.01; domperidone: 0.5 µM:+57 ms, 1 µM:+79 ms, 2 µM:+99 ms, p < 0.01). This was accompanied by a significant increase in action potential duration at 90% of repolarization. Administration of both agents also increased dispersion of repolarization (ondansetron: 1 µM:+12 ms, 5 µM:+17 ms; 10 µM:+18 ms, p < 0.05; domperidone: 0.5 µM:+19 ms, 1 µM:+27 ms; 2 µM:+23 ms p < 0.05). Lowering of potassium concentration in bradycardic AV-blocked hearts provoked early afterdepolarizations (EADs) in 9 of 10 ondansetron-treated hearts and induced polymorphic ventricular tachycardia (VT) resembling torsade de pointes in 7 of 10 ondansetron-treated hearts (86 episodes). Under the influence of domperidone, EAD and polymorphic VT occurred in 7 of 8 hearts (131 episodes). In the present study, both ondansetron and domperidone demonstrated a severe proarrhythmic potential. A significant prolongation of cardiac repolarization as well as a marked increase in spatial dispersion of repolarization represents the underlying electrophysiologic mechanisms. These results imply that application of ondansetron should be handled carefully. For regular administration, ECG monitoring should be mandatory.