Dronedarone: A New Treatment for Atrial Fibrillation

A value-based budget impact model for dronedarone compared with other rhythm control strategies

Aim: The budgetary consequences of increasing dronedarone utilization for treatment of atrial fibrillation were evaluated from a US payer perspective. Materials & methods: A budget impact model over a 5-year time horizon was developed, including drug-related costs and risks for long-term clinical outcomes (LTCOs). Treatments included antiarrhythmic drugs (AADs; dronedarone, amiodarone, sotalol, propafenone, dofetilide, flecainide), rate control medications, and ablation. Direct comparisons and temporal and non-temporal combination scenarios investigating treatment order were analyzed as costs per patient per month (PPPM). Results: By projected year 5, costs PPPM for dronedarone versus other AADs decreased by $37.69 due to fewer LTCOs, treatment with dronedarone versus ablation or rate control medications + ablation resulted in cost savings ($359.94 and $370.54, respectively), and AADs placed before ablation decreased PPPM costs by $242 compared with ablation before AADs. Conclusion Increased dronedarone utilization demonstrated incremental cost reductions over time.

Comparative Safety and Effectiveness of Sotalol Versus Dronedarone After Catheter Ablation for Atrial Fibrillation

Background Atrial tachyarrhythmias are common after atrial fibrillation ablation, so adjunctive antiarrhythmic drug therapy is often used. Data on the effectiveness and safety of dronedarone and sotalol after AF ablation are limited. Here, we compared health outcomes of ablated patients treated with dronedarone versus sotalol. Methods and Results A comparative analysis of propensity score-matched retrospective cohorts was performed using IBM MarketScan Research Databases. Patients treated with dronedarone after atrial fibrillation ablation were matched 1:1 to patients treated with sotalol between January 1, 2013 and March 31, 2018. Outcomes of interest included cardiovascular hospitalization, proarrhythmia, repeat ablation, and cardioversion. This study was exempt from institutional review board review. Among 30 696 patients who underwent atrial fibrillation ablation, 2086 were treated with dronedarone and 3665 with sotalol after ablation. Propensity-score matching resulted in 1815 patients receiving dronedarone matched 1:1 to patients receiving sotalol. Risk of cardiovascular hospitalization was lower with dronedarone versus sotalol at 3 months (adjusted hazard ratio [aHR], 0.77 [95% CI, 0.61-0.97]), 6 months (aHR, 0.76 [95% CI, 0.63-0.93]), and 12 months after ablation (aHR, 0.70 [95% CI, 0.66-0.93]). Risk of repeat ablation and cardioversion generally did not differ between the 2 groups. A lower risk of proarrhythmia was associated with dronedarone versus sotalol at 3 months (aHR, 0.76 [95% CI, 0.64-0.90]), 6 months (aHR, 0.80 [95% CI, 0.70-0.93]), and 12 months (aHR, 0.83 [95% CI, 0.73-0.94]) after ablation. Conclusions These data suggest that dronedarone may be a more effective and safer alternative after ablation than sotalol.

Pharmacokinetic interaction between dronedarone and ticagrelor following oral administration in rats

Dronedarone and ticagrelor have high co-administration potential in patients with both acute coronary syndrome and atrial fibrillation. The objective of the present in vivo study was to investigate the potential interaction between dronedarone (5 and 10 mg/kg) and ticagrelor (5 and 10 mg/kg) when administered orally to rats. Forty Sprague-Dawley rats were randomly distributed into eight groups; consisting of a dronedarone only group, a ticagrelor only group, a dronedarone with ticagrelor-pretreatment group, and a ticagrelor with dronedarone-pretreatment group. Pharmacokinetic exposure (AUC_inf = 1472 ng·h/mL) associated with administration of 10 mg/kg of dronedarone increased significantly, with delayed T _max in the group that received ticagrelor-pretreatment when compared to the dronedarone only group (AUC_inf = 723 ng·h/mL). In addition, pharmacokinetic exposure (AUC_inf = 2391 ng·h/mL) associated with administration of 10 mg/kg of ticagrelor increased significantly, with increased K _el (0.31 h^-1) and decreased V _z/F (14.6 L/kg) in the dronedarone-pretreatment group when compared to the ticagrelor only group (AUC_inf = 1616 ng·h/mL; K _el = 0.21 h^-1; V _z/F  =  31.3 L/kg). Results of our study suggest that further investigation of a potential interaction between dronedarone and ticagrelor in humans is justified and that caution may need to be exercised when dronedarone and ticagrelor pharmacotherapies concomitantly.

Electrochemical Cross-Dehydrogenative Coupling between Phenols and β-Dicarbonyl Compounds: Facile Construction of Benzofurans

Preparative electrochemical synthesis is an ideal method for establishing green, sustainable processes. The major benefits of an electro-organic strategy over that of conventional chemical synthesis are the avoidance of reagent waste and mild reaction conditions. Here, an intermolecular cross-dehydrogenative coupling between phenols and β-dicarbonyl compounds has been developed to build various benzofurans under undivided electrolytic conditions. Neither transition metals nor external chemical oxidants are required to facilitate the dehydrogenation and dehydration processes. The key factor in success was the use of nBu₄ NBF₄ as the electrolyte and hexafluoroisopropanol as the solvent, which play key roles in the cyclocondensation step. This electrolysis is scalable and can be used as a key step in drug synthesis. On the basis of several experimental results, the mechanism, particularly of the remarkable anodic oxidation and cyclization process, was illustrated.

Comparative evaluation of the hepatotoxicity, phototoxicity and photosensitizing potential of dronedarone hydrochloride and its cyclodextrin-based inclusion complexes

In this study, the hepatotoxicity, phototoxicity and photosensitizing potential of free dronedarone (DRO) and its inclusion complexes with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), prepared by different methods, were investigated by using in vitro cell-based approaches. The results of the 3T3 NRU phototoxicity assay showed that free DRO and the CD-based inclusion complexes did not present any substantial phototoxic potential. The photosensitizing potential was assessed by using THP-1 cells and IL-8 as a biomarker, and the experimental data confirmed that both the free drug and the inclusion complexes are likely to cause skin photosensitization, as they were able to induce IL-8 release after irradiation. Nevertheless, the inclusion complexes obtained by kneading followed by spray-drying induced a lower IL-8 release and also presented a smaller stimulation index in comparison with free DRO, suggesting a reduction in the photosensitizing potential. Finally, the free drug and inclusion complexes were also tested for hepatotoxicity using HepG2 cells. Even though lower IC50 values were found for the inclusion complexes prepared by kneading followed by spray-drying, there was no significant difference, indicating that the complexation of dronedarone did not induce hepatotoxicity. Overall, the obtained data confirmed that the inclusion complexes prepared by kneading followed by spray-drying, especially those based on HP-β-CD, appeared to be the most promising formulations and, therefore, could be encouragingly explored in the development of novel pharmaceutical dosage forms containing DRO, presumably with reduced side effects and improved safety profile.

Elevated liver enzymes associated with dronedarone for atrial fibrillation

A 51-year-old male with documented atrial fibrillation who was taking dronedarone 400 mg twice daily for approximately 3 months returned to the cardiologist for an ablation procedure. Baseline liver enzymes were within normal range prior to starting the medication and increased after the 3 months of therapy. Aspartate aminotransferase increased from 31 IU/L to 98 IU/L, and alanine aminotransferase increased from 21 IU/L to 101 IU/L. Two and a half months after discontinuation of the medication, liver enzymes normalized (aspartate aminotransferase: 30 IU/L and alanine aminotransferase: 25 IU/L). The Food and Drug Administration has now alerted health-care professionals of the potential for liver injury based upon post-marketing surveillance. The chronological course of elevated liver enzymes noted in our patient is suggestive of a dronedarone-induced problem. Clinicians should have a heightened awareness of the potential for liver enzyme elevation and injury with dronedarone and should monitor enzymes periodically, especially within the first 6 months of use.

Antiarrhythmic drugs for the maintenance of sinus rhythm: risks and benefits

Atrial fibrillation (AF) is the most common arrhythmia seen in clinical practice, and its complications impose a significant economic burden. The development of more effective agents to manage patients with AF is essential. While clinical trials show no major differences in outcomes between rate and rhythm control strategies, some patients with AF require treatment with antiarrhythmic drugs (AADs) to maintain sinus rhythm, reduce symptoms, improve exercise tolerance, and improve quality of life. Currently available AADs, while effective, have limitations including limited efficacy, adverse events, toxicity, and proarrhythmic potential. The 6 most commonly used AADs (amiodarone, disopyramide, dofetilide [USA but not Europe], flecainide, propafenone, sotalol) have proarrhythmic effects (fewer with amiodarone). Amiodarone is the most effective AAD, but its safety profile limits its usefulness. Recent advances in AAD therapy include dronedarone and vernakalant. Dronedarone, approved by the United States Food and Drug Administration and the European Medicines Authority and others, has been proven efficacious in maintaining sinus rhythm and reducing the incidence of hospitalization due to cardiovascular events or death in patients with AF. The intravenous formulation of vernakalant is approved in the European Union, Iceland, and Norway. Oral vernakalant is currently undergoing evaluation for preventing AF recurrence and appears to be effective with an acceptable safety profile. Treatment should be individualized to the patient with consideration of pharmacologic risks and benefits according to AF management guidelines. Accumulating efficacy and safety data for new and emerging AADs holds promise for improved AF management and outcomes.

Dronedarone: Uncertainties Continue to Emerge over its Role in the Treatment of Atrial Fibrillation

Dronedarone is a class III antiarrhythmic drug. Another class III drug, amiodarone, is currently the most commonly used antiarrhythmic drug for the maintenance of sinus rhythm in patients with atrial fibrillation (AF). However, its use is complicated by toxicities and complex dosing. Dronedarone is a structural derivative of amiodarone developed to provide a safer alternative. The efficacy of dronedarone has been demonstrated in patients with paroxysmal or persistent AF. A recent trial was conducted to determine whether these benefits extend to patients with permanent AF. This article will discuss the implications of this trial and the evolving role of dronedarone in the management of AF.

Update on the clinical management of atrial fibrillation: guidelines and beyond

In clinical practice, atrial fibrillation (AF) is the most commonly encountered arrhythmia. With the aging of the US population, the number of patients with AF that physicians encounter will increase. Atrial fibrillation management involves a combination of rate- and rhythm-control strategies with thromboprophylaxis, a complicated endeavor given side effect profiles of treatments, patient comorbidities, and anticoagulation treatment requirements. Early treatment discontinuation and poor compliance with anticoagulation treatment are frequent and result in increased mortality, a 5-fold increased risk of ischemic stroke, decreased health-related quality of life, and decreased exercise capacity. In 2006, the American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) provided guidelines for the management of patients with AF. Recently, the ACC Foundation, AHA, and Heart Rhythm Society released updates to these guidelines (January and February 2011). This article aims to assist physicians in improving the management of patients with AF by focusing on the main components of therapy as reflected in the guidelines, and by providing an update on new US Food and Drug Administration-approved treatments.

The management of patients with atrial fibrillation and dronedarone's place in therapy

The pharmacologic management of atrial fibrillation (AF) includes rate and rhythm control strategies. Antiarrhythmic agents (eg, amiodarone, flecainide, and propafenone) are limited by serious toxicities (including proarrhythmic effects and pulmonary toxicity), which may lead to a reduced net clinical efficacy of rhythm control strategies. Dronedarone, a new antiarrhythmic agent, is effective in the maintenance of sinus rhythm. Dronedarone has also been shown to reduce ventricular rate and the incidence of hospitalization due to cardiovascular events. Dronedarone is recommended by the 2011 American College of Cardiology Foundation/American Heart Association/Heart Rhythm Society guidelines update for the management of AF patients with no or minimal heart disease, coronary artery disease, and hypertension with no left ventricular hypertrophy. Dronedarone is contraindicated in patients with New York Heart Association (NYHA) class IV heart failure or NYHA class II-III heart failure with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic.

Evaluation of dronedarone use in the US patient population between 2009 and 2010: a descriptive study using a claims database

BACKGROUND

The utilization pattern of dronedarone was unknown, especially regarding prescribers' compliance with the product's prescribing information (PI) following its availability and the implementation of the Food and Drug Administration-approved risk evaluation and mitigation strategy for the drug in the United States.

OBJECTIVE

This study was designed to evaluate the dronedarone prescribers' adherence to PI regarding the following contraindications: (1) patients with heart failure (HF) with a recent decompensation requiring hospitalization or referral to a specialist, (2) concomitant use of potent CYP3A4 inhibitors, and (3) concomitant use of QT-prolonging drugs.

METHODS

Patients prescribed dronedarone between July 2009 and August 2010 were identified through LabRx. The following rates surrounding dronedarone use were examined: (1) atrial fibrillation or atrial flutter in the past year, (2) worsening or hospitalization for HF within the month before prescription, and (3) concomitant prescription of potent CYP3A4 inhibitors and concomitant prescription of QT-prolonging drugs within the following month.

RESULTS

A total of 4595 dronedarone prescriptions were filled by 1820 patients. More than 94% of the participants had ≥1 diagnosis of atrial fibrillation or atrial flutter in the previous year. Worsening of or hospitalization for HF was found in 61 (3.4%) patients within the month before receiving dronedarone, including 18 patients with HF as the primary cause for hospitalization. Potent CYP3A4 inhibitors were prescribed to 10 (0.6%) patients within a month following dronedarone initiation, 6 of whom received them for topical use only. QT-prolonging drugs were prescribed to 67 (3.7%) patients within a month following dronedarone initiation, among which >90% were other antiarrhythmics.

CONCLUSIONS

Dronedarone was used mostly in compliance with PI and risk evaluation and mitigation strategy in the studied population. In the LabRx database, dronedarone was commonly dispensed to patients with cardiovascular risk factors and rarely dispensed to patients with contraindications such as worsening HF or hospitalization for HF or with concomitant prescriptions of potent CYP3A4 inhibitors, QT-prolonging drugs, or both.

Suppression of ventricular tachycardia with dronedarone: a case report

 

INTRODUCTION

Dronedarone is a multichannel blocker with similar electrophysiological properties to amiodarone. Dronedarone has not been studied in humans as an agent to suppress ventricular arrhythmias.

METHODS

This case report describes the dramatic antiarrhythmic effects of dronedarone in a patient with nonischemic cardiomyopathy and recurrent ventricular tachycardia, which was resistant to multiple antiarrhythmic agents and endocardial catheter ablation.

RESULTS

Dronedarone was effective in completely suppressing ventricular tachycardia.

CONCLUSION

Further research is needed to establish a potential larger role for dronedarone in controlling ventricular arrhythmias in humans.

Rhythm control for management of patients with atrial fibrillation: balancing the use of antiarrhythmic drugs and catheter ablation

Antiarrhythmic drug (AAD) therapy may be beneficial for patients with symptoms attributable to atrial fibrillation despite adequate rate control. The limited long-term efficacy of AAD and the relatively large proportion of patients discontinuing therapy because of side effects led to the development of nonpharmacological therapies to achieve rhythm control. Pressing questions remain about the effect of ablation therapy on long-term patient outcomes. Based on recent clinical trials and meta-analyses, ablation appears more effective and possibly safer than AAD for long-term maintenance of sinus rhythm in selected patients, but the evidence is insufficient to recommend ablation in preference to drug therapy as the first AAD therapy for the majority of patients in whom a rhythm control strategy is justified. Herein, we review the most current evidence supporting the use of AAD and catheter ablation in atrial fibrillation.

Pharmacologic Conversion of Atrial Fibrillation and Atrial Flutter

Atrial fibrillation and atrial flutter are common arrhythmias in everyday clinical settings. Pharmacologic cardioversion (CV) is a simple and widely used strategy for the treatment of these arrhythmias, and many drugs are currently available. The choice of drug is strongly influenced by the time elapsed from atrial fibrillation onset and by a patient's clinical subset. Electrical direct-current CV is the treatment of choice in long-lasting forms; nevertheless, some agents also show efficacy in this setting. In addition, promising results come from studies on the efficacy and safety of new antiarrhythmic drugs and from therapeutic approaches that reduce the need for hospitalization and improve quality of life.

Dronedarone: an emerging therapy for atrial fibrillation

Atrial fibrillation (AF) is a common arrhythmia, with a prevalence ranging from 0.1% to 9.0% at different ages, and is associated with increased cardiovascular events and mortality. A significant increase in the prevalence of the disease is expected to occur in the coming years as a consequence of the aging of the population and advances in the management of coronary artery disease and heart failure. Effective rhythm control may be difficult to obtain in a significant proportion of patients with AF. The limited efficacy and the possible adverse effects of antiarrhythmic drugs has led researchers to focus their attention on new molecules, in a search of compounds with antiarrhythmic efficacy and a more favourable safety profile. Among several new drugs developed for the management of AF, dronedarone, a benzofuran derivative that shares many of the antiarrhythmic properties of amiodarone, but with a more favourable safety profile, seems particularly promising. The drug is noniodinated, has less lipophilicity, reaches therapeutic concentrations over a shorter period of time and has lower tissue accumulation. Dronedarone, similarly to amiodarone, exhibits electrophysiologic characteristics of all 4 Vaughan Williams classes. Clinical studies have shown that dronedarone effectively reduces ventricular rate, may prevent or delay the recurrence of AF, and may reduce cardiovascular morbidity and mortality in patients with AF or atrial flutter. The drug has an overall good safety profile, in particular with low pulmonary and thyroid toxicity. An important exception is represented by patients with unstable haemodynamic conditions, in which the use of dronedarone has been found to be associated with an increase in mortality. Dronedarone has been recently approved for clinical use by the Food and Drug Administration and by the European Medicines Agency. Further results from trials and clinical use will better define the efficacy and safety profile of dronedarone in AF compared with other antiarrhythmic drugs and its role in the management of patients with AF.

The impact of new and emerging clinical data on treatment strategies for atrial fibrillation

INTRODUCTION

The Atrial Fibrillation (AF) Exchange Group, an international multidisciplinary group concerned with the management of AF, was convened to review recent advances in the field and the potential impact on treatment strategies.

METHODS

Issues discussed included epidemiology and the impact of the rising incidence of AF on health care systems, developments in pharmacological and surgical interventions in the management of arrhythmias and thromboprophylaxis, the potential to affect treatment strategies, and barriers to implementing them.

RESULTS

The incidence of AF and the associated burden on health care systems are increasing with aging populations, prevalence of comorbidities and more effective treatment of cardiovascular diseases. Advances in available medical treatments, in particular dronedarone and dabigatran, with other products in development, offer the possibility of changes in treatment paradigms and a greater emphasis on reducing hospitalizations and improvement in long-term outcomes instead of a symptom/safety-driven approach in which the priority is symptom suppression without provoking drug toxicity. Developments in catheter ablation techniques may mean that, in experienced centers, ablation may be offered as first-line treatment in selected patient populations. Barriers to optimal treatment include underdiagnosis, lack of recognition as a serious condition and as a risk factor for stroke, limited access to care, inadequate implementation of guidelines, and poor adherence to treatment.

CONCLUSIONS

The focus of the management of AF may be changing as a consequence of new treatments based on the outcome improvements they offer. However, the benefits will not be fully realized if guidelines and guidance are not observed in routine clinical practice.

Vanoxerine: cellular mechanism of a new antiarrhythmic

INTRODUCTION

There remains an unmet need for safe and effective antiarrhythmic drugs, especially for the treatment of atrial fibrillation. Vanoxerine is a drug that is free of adverse cardiac events in normal volunteers, yet is a potent blocker of the hERG (hK(v)11.1) cardiac potassium channel. Consequently,we hypothesized that vanoxerine might also be a potent blocker of cardiac calcium (Ca) and sodium (Na) currents, and would not affect transmural dispersion of repolarization.

METHODS

The whole cell patch clamp technique was used to measure currents from cloned ion channels overexpressed in stable cell lines and single ventricular myocytes. We measured intracellular action potentials from canine ventricular wedges and Purkinje fibers using sharp microelectrode technique.

RESULTS

We found that vanoxerine was a potent hK(v)11.1 blocker, and at submicromolar concentrations, it blocked Ca and Na currents in a strongly frequency-dependent manner. In the canine ventricular wedge preparation vanoxerine did not significantly affect transmural action potential waveforms, QT interval or transmural dispersion of repolarization.

CONCLUSIONS

Vanoxerine (1) is a potent blocker of cardiac hERG, Na and Ca channels; (2) block is strongly frequency-dependent especially for Na and Ca channels; and (3) transmural dispersion of ventricular repolarization is unaffected. The multichannel block and repolarization uniformity resemble the effects of amiodarone, the exemplar atrial fibrillation drug. Vanoxerine is a completely different chemical and has none of amiodarone's toxic effects. Vanoxerine has characteristics of a potentially effective and safe antiarrhythmic.

Dronedarone: Emergence of a New Therapeutic Option for the Treatment of Atrial Fibrillation

This continuing feature updates readers on recent developments in cardiovascular pharmacotherapy. Cardiovascular disease remains the number 1 killer in the United States, and more clinical outcome trials have been conducted in cardiology than in any other field of medicine. Given this rapidly expanding knowledge base, if pharmacists stay current with developments in drug therapy, they can have a significant impact on prevention and treatment.