Guidelines for reporting case studies and series on drug-induced QT interval prolongation and its complications following acute overdose

CARE-radiology statement explanation and elaboration: reporting guideline for radiological case reports

Despite the increasing number of radiological case reports, the majority lack a standardised methodology of writing and reporting. We therefore develop a reporting guideline for radiological case reports based on the CAse REport (CARE) statement. We established a multidisciplinary group of experts, comprising 40 radiologists, methodologists, journal editors and researchers, to develop a reporting guideline for radiological case reports according to the methodology recommended by the Enhancing the QUAlity and Transparency Of health Research network. The Delphi panel was requested to evaluate the significance of a list of elements for potential inclusion in a guideline for reporting mediation analyses. By reviewing the reporting guidelines and through discussion, we initially drafted 46 potential items. Following a Delphi survey and discussion, the final CARE-radiology checklist is comprised of 38 items in 16 domains. CARE-radiology is a comprehensive reporting guideline for radiological case reports developed using a rigorous methodology. We hope that compliance with CARE-radiology will help in the future to improve the completeness and quality of case reports in radiology.

QTc Prolongation in Poison Center Exposures to CredibleMeds List of Substances with "Known Risk of Torsades de Pointes"

Many drugs carry some risk of QT interval prolongation, which can lead to life-threatening dysrhythmias including Torsades de Pointes (TdP). CredibleMeds.org identifies medications categorized as "Known Risk of TdP" but does not stratify risk in acute supratherapeutic ingestions. We sought to determine the proportion of cases exhibiting QTc prolongation and life-threatening dysrhythmias including ventricular tachycardia (VT)/ventricular fibrillation (VF), TdP, and asystole in patients exposed to these substances. Retrospective chart review of cases reported to our Regional Poison Center from 2014 to 2019 of exposures to one or more of the "Known Risk" substances was performed. Demographics, therapies, clinical effects, and medical outcome for each case were analyzed. There were 1125 exposures, of which 760 had a documented QTc interval. QTc ≥ 500 ms was reported in 138 (18.2%) of the 760 cases. The most common "Known Risk" substances were citalopram, escitalopram and cocaine. Although not in the "Known Risk" category, mirtazapine, amitriptyline, diphenhydramine, and trazodone had a statistically significant association with QTc > 500 ms. Life-threatening dysrhythmias occurred in 13 cases, with VT/VF in 6 of the 760 (0.8%) cases, and one case of TdP. Flecainide (OR 11.1, 95% CI 2.2-55.8) and methadone (OR 7.1, 95% CI 2.1-23.4) were associated with increased risk of all life-threatening dysrhythmias. Exposures to medications on the Credible Meds list of "Known Risk of TdP" QTc prolongation is common, but life-threatening dysrhythmias are rare. Mirtazapine, amitriptyline, diphenhydramine, and trazodone were associated with prolonged QTc. Flecainide and methadone had the highest associated risk of life-threatening dysrhythmias.

Effect of Memantine on QT/QTc Interval in a Healthy Korean Population

Studies on the effects of memantine on QT prolongation have yielded conflicting results. For a long time, memantine was reported to be a safe drug without QT prolongation; however, several case studies have reported memantine-induced QT prolongation in Alzheimer's patients. This study evaluated the relationship between memantine blood levels, and QT interval changes. Over a 2-week period, we orally administered 20 mg of memantine daily to achieve a steady state in 57 healthy Korean subjects. We measured and analyzed the QT interval and blood memantine concentrations simultaneously before and after treatment, as well as 2 weeks after the last dosing. Correlation analysis was done between blood memantine level and QT interval. No serious adverse events occurred during the study period. Repeated dosing of memantine did not show clinically significant QT interval changes after treatment. Regression analysis was performed based on the results; there was no statistical association between memantine blood level and QT prolongation. In conclusion, the results of the present study demonstrated no clinically significant changes in the QT interval with therapeutic blood levels of memantine.