Pharmacometric and Electrocardiographic Evaluation of Chloroquine and Azithromycin in Healthy Volunteers.

Chloroquine and azithromycin were developed in combination for the preventive treatment of malaria in pregnancy, and more recently were proposed as coronavirus disease 2019 (COVID-19) treatment options. Billions of doses of chloroquine have been administered worldwide over the past 70 years but concerns regarding cardiotoxicity, notably the risk of torsades de pointes (TdP), remain. This investigation aimed to characterize the pharmacokinetics and electrocardiographic effects of chloroquine and azithromycin observed in a large previously conducted healthy volunteer study. Healthy adult volunteers (n = 119) were randomized into 5 arms: placebo, chloroquine alone (600 mg base), or chloroquine with either 500 mg, 1,000 mg, or 1,500 mg of azithromycin all given daily for 3 days. Chloroquine and azithromycin levels, measured using liquid-chromatography tandem mass spectrometry, and electrocardiograph intervals were recorded at frequent intervals. Time-matched changes in the PR, QRS, and heart rate-corrected JT, and QT intervals were calculated and the relationship with plasma concentrations was evaluated using linear and nonlinear mixed-effects modeling. Chloroquine and azithromycin pharmacokinetics were described satisfactorily by two- and three-compartment distribution models, respectively. No drug-drug interaction between chloroquine and azithromycin was observed. Chloroquine resulted in concentration-dependent prolongation of the PR, QRS, JTc and QTc intervals with a minimal additional effect of azithromycin. QRS widening contributed ~ 28% of the observed QT prolongation. Chloroquine causes significant concentration-dependent delays in both ventricular depolarization and repolarization. Co-administration of azithromycin did not significantly increase these effects. The arrhythmogenic risk of TdP associated with chloroquine may have been substantially overestimated in studies which did not separate electrocardiograph QRS and JT prolongation.

Safety profile of hydroxychloroquine used off-label for the treatment of patients with COVID-19: A descriptive study based on EudraVigilance data.

At the beginning of the COVID-19 pandemic, worldwide attempts were made to identify potential drugs effective against the COVID-19. Hydroxychloroquine was among the first receiving attention. However, following its use in therapy, it has been shown that hydroxychloroquine was not only ineffective but probably, due to its known side effects, even responsible of increased mortality of patients. The objective of this study was to review the safety profile of hydroxychloroquine used off-label for the treatment of COVID-19. We analyze the reports of suspected adverse drug reactions (ADRs) collected in EudraVigilance, the European database of ADR reports. We collected 2266 reports for 2019 and 6525 for 2020. The most reported ADRs during 2020 were those relating to cardiac, hepatic, renal toxicity such as QT prolongation with 400 cases in 2020 (of which, 345 cases-9.97%-with COVID-19 as a therapeutic indication) versus 1 case only in 2019 (0.01%), long QT syndrome: 38 cases in 2020 (36 as COVID-19 treatment) versus 0 in 2019, hepatitis: 13 cases in 2019 (0.11%) and 132 in 2020, and 32 cases (24, 0.69%) of acute kidney injury in 2020 and only 3 cases in 2019. Moreover, some important vision-related ADRs also increased significantly during 2020, such as retinal toxicity with 92 cases in 2020 versus 7 in 2019. Even though with its intrinsic limitations, our results may be added to the most recent scientific evidence to confirm the unfavorable risk profile of hydroxychloroquine in its off-label use in the treatment of COVID-19 disease.

Acquired long QT syndrome due to antiemetics, COVID-19 and Blastocystis hominis induced exacerbation of congenital chloride losing diarrhoea.

Congenital chloride losing diarrhoea (CCLD) is a rare disease caused by mutations in an intestinal chloride/bicarbonate ion exchange channel. Few reports describe CCLD in adults and none has described the impact of a parasitic infection on CCLD. Severe diarrhoea may result in hypokalaemia with QT interval prolongation. Treatment with antiemetics may further increase the QT interval. To raise awareness of this preventable complication, we describe the course of a woman in her 20s with CCLD who developed COVID-19 and a Blastocystis hominis infestation. Treatment with antiemetics and hypokalaemia resulted in prolongation of the QT interval to 640 ms. While, the QT interval normalised with discontinuation of antiemetics and electrolyte replacement, patients with CCLD must take precautions to prevent gastrointestinal infections. Regardless, whenever patients with CCLD present to hospital, the authors recommend monitoring the QT interval and avoiding medications that predispose to torsade de pointes.

QTc interval prolongation in patients infected with SARS-CoV-2 and treated with antiviral drugs.

INTRODUCTION: Many antiviral agents, such as hydroxychloroquine, have been used to treat COVID-19, without being broadly accepted. QTc prolongation is a worrisome adverse effect, scarcely studied in pediatrics. PATIENTS AND METHODS: Paediatric patients affected from COVID-19 who received antivirals were matched (1:2) with controls not infected nor exposed. Electrocardiograms were prospectively analyzed at baseline, during the first 72 h of treatment and after 72 h. RESULTS: Eleven (22.9%) out of 48 patients admitted due to COVID-19 (March-July 2020) received antiviral therapy. All had underlying diseases: congenital heart disease (4/11; 36.4%) and immunosuppression (3/11; 27.3%) stand out. 5/11 (45.5%) received treatment at baseline with a potential effect on QTc. There where no differences observed in the baseline QTc between cases and controls: 414.8 ms (49.2) vs 416.5 ms (29.4), (P = .716). Baseline long QT was observed in 2/11 cases and 2/22. Among cases, 10/11 (90.9%) received hydroxychloroquine, mainly associated with azithromycin (8/11; 72.7%), 3 received lopinavir/ritonavir and one remdesivir. The median increase in QTc after 72 h under treatment was 28.9 ms [IQR 48.7] (P = .062). 4/11 (36.4%) patients had a long QTc at 72 h, resulting in 3 patients ≥500 ms; treatment was stopped in one (QTc 510 ms) but ventricular arrhythmias were not documented. CONCLUSIONS: The use of antivirals caused an increase on the QTc interval after 72 h of treatment, being the QTc long in 36.3% of the patients, although no arrhythmic events were observed. The use of hydroxychloroquine and antivirals requires active QTc monitoring and it is recommended to discontinue treatment if QTc > 500 ms.

Long QT interval and syncope after a single dose of COVID-19 vaccination: a case report.

Adverse consequences of the coronavirus disease 2019 (COVID-19) vaccination which have been reported in scientific papers are varied. One possible but rare consequence is myocarditis, which may have a diversity of clinical manifestations. We report a case of a 70-year-old man who presented to the hospital for some syncope, 3 days after his first COVID-19 AstraZeneca Vaccination. Initial electrocardiogram (ECG) showed a long QT interval (QTc = 600 milliseconds). Laboratory tests revealed elevated troponin and lack of evidence of viral infection. Further investigations revealed the vaccine-induced myocarditis and arrhythmias linked to it. Within one week of magnesium treatment, the QT interval was completely corrected, and the patient discharged with no typical syncope attacks. This case like the previous reported one confirms that myocarditis is a complication of COVID-19 vaccine, but implies its clinical manifestations may be varied and even may happen after the single dose of vaccination.

COVID-19 FAQs in paediatric and congenital cardiology: AEPC position paper.

The COVID-19 pandemic has had a huge influence in almost all areas of life, affecting societies, economics, and health care systems worldwide. The paediatric cardiology community is no exception. As the challenging battle with COVID-19 continues, professionals from the Association for the European Paediatric and Congenital Cardiology receive many questions regarding COVID-19 in a Paediatric and Congenital Cardiology setting. The aim of this paper is to present the AEPC position on frequently asked questions based on the most recent scientific data, as well as to frame a discussion on how to take care of our patients during this unprecedented crisis. As the times are changing quickly and information regarding COVID-19 is very dynamic, continuous collection of evidence will help guide constructive decision-making.

Assessing QT interval in COVID-19 patients:safety of hydroxychloroquine-azithromycin combination regimen.

BACKGROUND: Hydroxychloroquine (HCQ) and azithromycin (AZT) have been proposed for COVID-19 treatment. Data available in the literature reported a potential increased risk of fatal arrhythmias under these therapies. The aim of this study was to assess the effects of these drugs on QT interval and outcome in a COVID-19 population. METHOD: A total of 112 consecutive COVID-19 patients were included in this analysis and were divided in 3 groups according to the receiving therapeutic regimens: 19 (17%) patients in Group 1 (no treatment), 40 (36%) in Group 2 (HCQ only), 53 (47%) in Group 3 (HCQ/AZT). RESULTS: A prolonged QTc interval was found in 61% of patients treated with HCQ alone or in combination with AZT, but only 4 (4%) patients showed a QTc > 500 ms. HCQ/AZT combination determined a greater increase of QTc duration compared to the other two strategies (Group 3 452 ± 26.4 vs Group 2 436.3 ± 28.4 vs Group 1 424.4 ± 24.3 ms, respectively; p < 0.001). Multivariate analysis demonstrated that HCQ/AZT combination (OR 9.02, p = 0.001) and older age (OR 1.04, p = 0.031) were independent predictors of QTc prolongation. The risk increased with age (incremental utility analysis p = 0.02). Twenty patients (18%) died, and no cardiac arrest neither arrhythmic fatalities were documented. CONCLUSIONS: The HCQ/AZT combination therapy causes a significantly increase of QT interval compared to HCQ alone. Older patients under such regimen are at higher risk of experiencing QT prolongation. The use of such drugs may be considered as safe relating to arrhythmic risk in the treatment of COVID-19 patients as no arrhythmic fatalities occurred.

Hydroxychloroquine/azithromycin treatment, QT interval and ventricular arrhythmias in hospitalised patients with COVID-19.

BACKGROUND: Hydroxychloroquine (HCQ) and azithromycin (AZM) are widely used in off-label treatment of novel coronavirus disease (COVID-19). However, cardiac safety of these drugs is still controversial in COVID-19. Therefore, we aimed to evaluate association of HCQ or HCQ + AZM treatment regimens, corrected QT (QTc) interval and malignant ventricular arrhythmias in hospitalized patients. METHODS: This is a single-center, retrospective and observational study. All data were extracted from the electronic medical records. The initial and post-treatment mean QTc intervals were calculated and compared in patients with HCQ alone or HCQ + AZM therapy. Associated factors with QTc prolongation, the incidence of ventricular arrhythmia during treatment and in-hospital mortality because of ventricular arrhythmias were evaluated. RESULTS: Our cohort comprised 101 hospitalized COVID-19 patients (mean age of 49.60 ± 18 years, 54.4% men). HCQ + AZM combination therapy group (n = 56) was more likely to have comorbidities. After 5-days treatment, 19 (18.8%) patients had QTc prolongation, and significant increase in the QTc interval was observed in both two groups (P < .001). However, HCQ + AZM combination group had significantly higher ΔQTc compared to HCQ group (22.5 ± 18.4 vs 7.5 ± 15.3 ms, P < .001). All of 101 patients completed the 5-days treatment without interruption. Also, no malignant ventricular arrhythmia or death secondary to ventricular arrhythmia occurred during the treatment in both groups. CONCLUSIONS: The present study revealed that although HCQ + AZM treatment was independently associated with QTc prolongation, none of patients experienced malignant ventricular arrhythmia or death during treatment. Further prospective studies are needed to determine the exact implications of these drugs on arrhythmias in patients with COVID-19.

QTc prolongation among hydroxychloroquine sulphate-treated COVID-19 patients: An observational study.

BACKGROUND: The liberal administration of hydroxychloroquine-sulphate (HCQ) to COVID-19 patients has raised concern regarding the risk of QTc prolongation and cardiac arrhythmias, particularly when prescribed with azithromycin. We evaluated the incidence of QTc prolongation among moderately and severely ill COVID-19 patients treated with HCQ and of the existence of concomitant alternative causes. METHODS: All COVID-19 patients treated with HCQ (between Mar 1 and Apr 14, 2020) in a tertiary medical centre were included. Clinical characteristics and relevant risk factors were collected from the electronic medical records. Individual patient QTc intervals were determined before and after treatment with HCQ. The primary outcome measure sought was a composite end point comprised of either an increase ≥60 milliseconds (ms) in the QTc interval compared with pre-treatment QTc, and/or a maximal QTc interval >500 ms RESULTS: Ninety patients were included. Median age was 65 years (IQR 55-75) and 57 (63%) were male. Thirty-nine patients (43%) were severely or critically ill. Hypertension and obesity were common (n = 23 each, 26%). QTc prolongation evolved in 14 patients (16%). Age >65 years, congestive heart failure, severity of disease, C-reactive protein level, hypokalaemia and furosemide treatment, were all associated with QTc prolongation. Adjusted analysis showed that QTc prolongation was five times more likely with hypokalaemia [OR 5, (95% CI, 1.3-20)], and three times more likely with furosemide treatment [OR 3 (95% CI, 1.01-13.7)]. CONCLUSION: In patients treated with HCQ, QTc prolongation was associated with the presence of traditional risk factors such as hypokalaemia and furosemide treatment.

Prolonged QT Interval in a Patient With Coronavirus Disease-2019: Beyond Hydroxychloroquine and Azithromycin.

Recent reports have suggested an increased risk of QT prolongation and subsequent life-threatening ventricular arrhythmias, particularly torsade de pointes, in patients with coronavirus disease-2019 (COVID-19) treated with hydroxychloroquine and azithromycin. In this article, we report the case of a 75-year-old female with a baseline prolonged QT interval in whom the COVID-19 illness resulted in further remarkable QT prolongation (>700 ms), precipitating recurrent self-terminating episodes of torsade de pointes that necessitated temporary cardiac pacing. Despite the correction of hypoxemia and the absence of reversible factors, such as adverse medication effects, electrolyte derangements, and usage of hydroxychloroquine/azithromycin, the QT interval remained persistently prolonged compared with the baseline with subsequent degeneration into ventricular tachycardia and death. Thus, we highlight that COVID-19 illness itself can potentially lead to further prolongation of QT interval and unmask fatal ventricular arrhythmias in patients who have a prolonged QT and low repolarization reserve at baseline.

QT prolongation in a diverse, urban population of COVID-19 patients treated with hydroxychloroquine, chloroquine, or azithromycin.

PURPOSE: Hydroxychloroquine, chloroquine, and azithromycin have been used for treatment of COVID-19, but may cause QT prolongation. Minority populations are disproportionately impacted by COVID-19. This study evaluates the risk of QT prolongation and subsequent outcomes after administration of these medications in largely underrepresented minority COVID-19 patients. METHODS: We conducted an observational study on hospitalized COVID-19 patients in the Montefiore Health System (Bronx, NY). We examined electrocardiograms (ECG) pre/post-medication initiation to evaluate QTc, HR, QRS duration, and presence of other arrhythmias. RESULTS: One hundred five patients (mean age 67 years; 44.8% F) were analyzed. The median time from the first dose of any treatment to post-medication ECG was 2 days (IQR: 1-3). QTc in men increased from baseline (440 vs 455 ms, p < 0.001), as well as in women (438 vs 463 ms, p < 0.001). The proportion of patients with QT prolongation increased significantly (14.3% vs 34.3%, p < 0.001) even when adjusted for electrolyte abnormalities. The number of patients whose QTc > 500 ms was significantly increased after treatment (16.2% vs. 4.8%, p < 0.01). Patients with either QTc > 500 ms or an increase of 60 ms had a higher frequency of death (47.6% vs. 22.6%, p = 0.02) with an odds ratio of 3.1 (95% CI: 1.1-8.7). Adjusting for race/ethnicity yielded no significant associations. CONCLUSIONS: Hydroxychloroquine, chloroquine, and/or azithromycin were associated with QTc prolongation but did not result in fatal arrhythmias. Our findings suggest that any harm is unlikely to outweigh potential benefits of treatment. Careful risk-benefit analyses for individual patients should guide the use of these medications. Randomized control trials are necessary to evaluate their efficacies.

COVID-19 and cardiac arrhythmias: a global perspective on arrhythmia characteristics and management strategies.

BACKGROUND: Cardiovascular and arrhythmic events have been reported in hospitalized COVID-19 patients. However, arrhythmia manifestations and treatment strategies used in these patients have not been well-described. We sought to better understand the cardiac arrhythmic manifestations and treatment strategies in hospitalized COVID-19 patients through a worldwide cross-sectional survey. METHODS: The Heart Rhythm Society (HRS) sent an online survey (via SurveyMonkey) to electrophysiology (EP) professionals (physicians, scientists, and allied professionals) across the globe. The survey was active from March 27 to April 13, 2020. RESULTS: A total of 1197 respondents completed the survey with 50% of respondents from outside the USA, representing 76 countries and 6 continents. Of respondents, 905 (76%) reported having COVID-19-positive patients in their hospital. Atrial fibrillation was the most commonly reported tachyarrhythmia whereas severe sinus bradycardia and complete heart block were the most common bradyarrhythmias. Ventricular tachycardia/ventricular fibrillation arrest and pulseless electrical activity were reported by 4.8% and 5.6% of respondents, respectively. There were 140 of 631 (22.2%) respondents who reported using anticoagulation therapy in all COVID-19-positive patients who did not otherwise have an indication. One hundred fifty-five of 498 (31%) reported regular use of hydroxychloroquine/chloroquine (HCQ) + azithromycin (AZM); concomitant use of AZM was more common in the USA. Sixty of 489 respondents (12.3%) reported having to discontinue therapy with HCQ + AZM due to significant QTc prolongation and 20 (4.1%) reported cases of Torsade de Pointes in patients on HCQ/chloroquine and AZM. Amiodarone was the most common antiarrhythmic drug used for ventricular arrhythmia management. CONCLUSIONS: In this global survey of > 1100 EP professionals regarding hospitalized COVID-19 patients, a variety of arrhythmic manifestations were observed, ranging from benign to potentially life-threatening. Observed adverse events related to use of HCQ + AZM included prolonged QTc requiring drug discontinuation as well as Torsade de Pointes. Large prospective studies to better define arrhythmic manifestations as well as the safety of treatment strategies in COVID-19 patients are warranted.