scholarly journals Torsades de Pointes after Ondansetron Infusion in 2 Patients

2017 ◽  
Vol 44 (5) ◽  
pp. 366-369 ◽  
Author(s):  
Danny Y. Lee ◽  
Tri Trinh ◽  
Sion K. Roy

Drugs that prolong the electrocardiographic QT interval increase the risk of ventricular arrhythmias, particularly torsades de pointes. Ondansetron, a 5-hydroxytryptamine type 3 receptor antagonist antiemetic, is one such drug. We present the cases of 2 patients who were given intravenous ondansetron and subsequently developed torsades de pointes. Both had normal QT intervals at baseline but were discovered to have risk factors that predisposed them to drug-induced QT prolongation and ventricular arrhythmias. We briefly review the mechanisms for torsades de pointes caused by QT-prolonging medications, describe characteristics that increase patients' susceptibility to drug-induced QT prolongation, and call attention to the risk of ventricular arrhythmias in patients who are given ondansetron.

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Mohamed Farhan Nasser ◽  
Ahmad Jabri ◽  
Saima Karim ◽  
Elizabeth Kaufman

Introduction: QT prolongation is associated with increased risk of ventricular arrhythmias.As many patients with COVID19 may be started on QT prolonging drugs, measuring and monitoring QT is imperative to prevent fatal ventricular arrhythmias. However, we need to limit exposure of staff to patients with confirmed COVID19 and judiciously use personal protective equipment. Thus, it is important to find alternatives to doing frequent 12-lead ECGs. Hypothesis: We hypothesize that the QT interval measured from telemetry is similar to the QT interval on 12-lead ECG. Methods: Telemetry recordings and 12-lead ECGs were obtained from 15 patients at the same time and identical heart rates. Patients were from two different inpatient units with the same telemetry monitoring service. QT intervals were measured manually using calipers with the tangent method, excluding U waves. Telemetry recordings included lead I and II or a precordial lead. QT from telemetry was compared to the corresponding leads and to the longest QT on the 12-lead ECG. In cases of atrial fibrillation (AF), the QT from all the complexes was averaged. Results: Of 15 patients, 2 were in AF and 2 had RBBB. One patient had abnormal T-wave morphology and QT prolongation (abnormal repolarization). In all patients, QT intervals from the same leads as telemetry matched the QT measured from 12-lead. In 14 of 15 patients, telemetry QT matched the longest QT on the 12-lead ECG. However, in the patient with abnormal repolarization, maximum QT on 12-lead ECG was substantially longer than telemetry QT (Figure 1). Conclusion: When using the same lead, QT intervals were identical on telemetry and 12-lead ECG. However, in the patient with abnormal repolarization, the longest QT on 12-lead ECG was not represented on telemetry. In patients with abnormal repolarization on 12-lead ECG, we recommend serial 12-lead ECGs while on QT-prolonging drugs. Telemetry may suffice as a surrogate for 12-lead ECG to follow QT intervals in most patients.


2020 ◽  
pp. postgradmedj-2020-138661
Author(s):  
Rani Khatib ◽  
Fatima R N Sabir ◽  
Caroline Omari ◽  
Chris Pepper ◽  
Muzahir Hassan Tayebjee

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.


2020 ◽  
Vol 9 (13) ◽  
Author(s):  
Magdalene M. Assimon ◽  
Lily Wang ◽  
Patrick H. Pun ◽  
Wolfgang C. Winkelmayer ◽  
Jennifer E. Flythe

Background The rate of sudden cardiac death in the hemodialysis population exceeds that of the general population by >20‐fold. Hemodialysis patients may be particularly susceptible to sudden cardiac death provoked by drug‐induced QT prolongation because of their substantial cardiovascular disease burden, exposure to electrolyte shifts during dialysis, and extensive polypharmacy. However, population‐specific data regarding the frequency and patterns of QT prolonging medication use are limited. Methods and Results We conducted a descriptive drug utilization study using 3 administrative databases, the United States Renal Data System, MarketScan, and Medicare claims. We characterized the extent and patterns of QT prolonging medication use by adult hemodialysis patients and individuals without end‐stage kidney disease annually from 2012 to 2016. We also identified instances of high‐risk QT prolonging medication use among hemodialysis patients. In total, 338 515 hemodialysis patients and 40.7 million individuals without end‐stage kidney disease were studied. Annual utilization rates of QT prolonging medications with known torsades de pointes risk in hemodialysis patients were ~1.4 to ~2.5 times higher than utilization rates in individuals without end‐stage kidney disease. Hemodialysis patients with demographic and clinical risk factors for drug‐induced QT prolongation were exposed to medications with known torsades de pointes risk more often than patients without risk factors. Conclusions Hemodialysis patients use QT prolonging medications with known torsades de pointes risk more extensively than individuals without end‐stage kidney disease. Given the widespread use and instances of high‐risk prescribing, future studies evaluating the cardiac safety of these drugs in the hemodialysis population are needed.


2018 ◽  
Vol 25 (8) ◽  
pp. 2004-2006 ◽  
Author(s):  
Jessica J Tilton ◽  
Rozhan Sadr ◽  
Vicki L Groo

Prolongation of the corrected QT interval can lead to the deadly arrhythmia torsades de pointes. There are many risk factors for corrected QT prolongation, one being medication. The goal of this case report is to add to the limited literature surrounding the possibility of torsades de pointes when levofloxacin and fluconazole are used concomitantly. Additionally, provide guidance for patient factors that need to be assessed when prescribing the two drugs.


2020 ◽  
Vol 31 (10) ◽  
pp. 2696-2701
Author(s):  
Philipp Krisai ◽  
Konstantinos Vlachos ◽  
F. Daniel Ramirez ◽  
Yosuke Nakatani ◽  
Takashi Nakashima ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Paul Singh ◽  
J. Martin Maldonado-Duran

We present a case of drug-induced QT prolongation caused by an escitalopram overdose in a patient with previously undiagnosed congenital LQTS. A 15-year-old Caucasian female presented following a suicide attempt via an escitalopram overdose. The patient was found to have a prolonged QT interval with episodes of torsades de pointes. The patient was admitted to the telemetry unit and treated. Despite the resolution of the torsades de pointes, she continued to demonstrate a persistently prolonged QT interval. She was seen by the cardiology service and diagnosed with congenital long QT syndrome. This case illustrates the potential for an escitalopram overdose to cause an acute QT prolongation in a patient with congenital LQTS and suggests the importance of a screening electrocardiogram prior to the initiation of SSRIs, especially in patients at high risk for QT prolongation.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
G Frommeyer ◽  
J Brandt ◽  
C Ellermann ◽  
J Wolfes ◽  
L Eckardt

Abstract Background Dexmedetomidine is increasingly employed for conscious sedation during electrophysiological procedures. Recent experimental data have suggested direct effects of dexmedetomidine on cardiac electrophysiology. The aim of the present study was to assess the effects of dexmedetomidin on drug-induced QT-prolongation. Methods and results In 12 isolated rabbit hearts the macrolide antibiotic erythromycin (300μM) was infused as a potent Ikr blocker after obtaining baseline data. Eight endo- and epicardial monophasic action potentials and a simultaneously recorded 12-lead ECG showed a significant prolongation of QT-interval (+25ms, p&lt;0.05) accompanied by a moderate increase of action potential duration (APD, +5ms, p=ns) after infusion of erythromycin as compared with baseline. Effective refractory period (ERP) was also elevated (+33ms, p&lt;0.05). Erythromycin (+26ms, p&lt;0.05) also significantly increased spatial dispersion of repolarisation. Additional infusion of dexmedetomidine (3μM) resulted in a rather stable QT-interval (+7ms, p=ns) and APD (+7ms, p=ns) as compared with sole erythromycin treatment. Of note, a significant decrease of spatial dispersion (−24ms, p&lt;0.05) was observed while ERP was moderately increased (+13ms, p=ns). Lowering of potassium concentration in bradycardic AV-blocked hearts resulted in the occurrence of early afterdepolarizations (EAD) and drug induced proarrhythmia with torsade de pointes in 6 of 12 erythromycin-treated hearts (40 episodes). Additional infusion of dexmedetomidine reduced the occurrence of torsade de pointes (4 of 12 hearts, 9 episodes). Conclusion Infusion of dexmedetomidine resulted in a reduction of spatial dispersion of repolarization in the presence of a prolonged repolarization period. This resulted in a reduction of torsade de pointes with dexmedetomidine. Furthermore, an increase of ventricular refractory periods reduced inducibility of ventricular arrhythmias. Thus, in an experimental setting dexmedetomidine shows significant antiarrhythmic effects, which may influence electrophysiologic findings during clinical electrophysiologic studies. This needs to be studied in the clinical setting. Funding Acknowledgement Type of funding source: None


COVID ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 458-464
Author(s):  
Marc Thomas Zughaib ◽  
Robby Singh ◽  
Marcel Letourneau ◽  
Marcel Elias Zughaib

Objectives: Our study aimed to investigate the frequency of malignant cardiac arrhythmias in hospitalized patients receiving hydroxychloroquine alone and those receiving a combination of hydroxychloroquine with azithromycin, as well as the quantitative extent of QT prolongation within Tisdale Risk Score (TRS) categories. Background: There have been over 33 million cases of SARS-CoV-2 (COVID-19) resulting in over 600,000 deaths in the United States. As the current COVID-19 pandemic continues, numerous medications have been administered to attempt to treat patients afflicted by the disease. While hydroxychloroquine has been in use for decades for rheumatologic and infectious disease processes, it does have potential cardiotoxicity related to drug-induced QT prolongation. Drug-induced QT prolongation has an increased risk of arrhythmogenicity, potentially progressing into torsades de pointes (TdP) and increased patient mortality. The relationship between QT prolongation and TdP is complex and inexact, but there remains optimism regarding the use of these medications in the treatment of COVID-19 despite limited data on their true efficacy. Methods: We retrospectively identified 75 patients who were admitted with COVID-19 and underwent treatment with hydroxychloroquine for 5 days. The hydroxychloroquine protocol was defined as an initial dose of 400 mg BID for the first day, followed by 400 mg daily for the next 4 days. Baseline demographics, medications, medical histories, lab values, ECG QT intervals, and Tisdale Risk Categories were collected for all patients. Results: Seventy-four (98.7%) patients completed the full course of hydroxychloroquine. There were 41 males (54.7%) and 34 females (45.3%). Average length of stay was 8.9 days (95% CI: 7.5, 10.2). One patient who could not complete the course due to inability to swallow medication tablets. There were no reports of new arrythmias or incidence of torsades de pointes during the study. Seventy-two patients (96%) were taking at least 2 QT prolonging medications. The average corrected QT intervals were as follows: day 1 of admission was 421.62 milliseconds (n = 66, 95% CI: 412.19, 431.05), day 2 was 431.50 ms (n = 30, 95% CI: 416.34, 446.66), day 3 was 433.48 ms (n = 23, 95% CI: 413.34, 453.61), day 4 was 427.59 ms (n = 17, 95% CI: 400.83, 454.35), and day 5 was 444.28 ms (n = 18, 95% CI: 428.43, 460.12). The corrected QT interval prolonged by 22.66 ms from day 1 to day 5 (p = 0.03) in the overall population. Conclusion: There were no patients who experienced arrhythmogenicity or Torsades de Pointes despite a statistically significant increase in QTc intervals after patients received the 5-day course of hydroxychloroquine for treatment of COVID-19.


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