Acute hepatitis secondary to parenteral amiodarone does not preclude subsequent oral therapy

Adverse events in different administration routes of amiodarone: a pharmacovigilance study based on the FDA adverse event reporting system

Background

Arrhythmias are prevalent cardiac disorders with significant impacts on patient quality of life and mortality. Amiodarone, a class III antiarrhythmic agent, is widely used to manage both atrial and ventricular arrhythmias due to its efficacy in prolonging the cardiac action potential and its multiple antiarrhythmic properties. While clinical trials have highlighted the safety and efficacy of amiodarone, there is limited real-world data on adverse events (AEs) associated with different administration routes. This study aims to address this gap by utilizing the U.S. Food and Drug Administration's Adverse Event Reporting System (FAERS) to investigate the spectrum and timing of AEs related to amiodarone administration through disproportionality analysis and stratification methods.

Methods

Data from the FAERS database were analyzed using disproportionality analysis and reporting odds ratio (ROR) methods for comparative analysis, and the Weibull distribution for time-to-adverse-event analysis. The study examined data from 2004 through the first quarter of 2024 to analyze adverse event signals and the time of occurrence between intravenous and oral amiodarone administration.

Results

A total of 16,749 records of adverse reactions associated with amiodarone were identified. Among these, 2,412 events were related to intravenous amiodarone, and 8,220 events were related to oral amiodarone. The analysis revealed that cardiac and hepatic AEs were more common with intravenous administration, while pulmonary and thyroid-related AEs were more frequent with oral administration. Furthermore, the onset of adverse reactions varied significantly between the routes. The Weibull distribution analysis showed a median onset time of 5 days for intravenous administration compared to 74 days for oral administration. Both routes exhibited early failure-type signals, indicating a decreasing risk of AEs over time.

Conclusion

Amiodarone exhibits varying adverse drug reactions and onset times across different routes of administration. Clinicians should carefully consider these differences when selecting the administration route to balance the risks of adverse reactions with therapeutic benefits.

Amiodarone Therapy: Updated Practical Insights

Amiodarone, a bi-iodinated benzofuran derivative, is among the most commonly used antiarrhythmic drugs due to its high level of effectiveness. Though initially categorized as a class III agent, amiodarone exhibits antiarrhythmic properties across all four classes of antiarrhythmic drugs. Amiodarone is highly effective in maintaining sinus rhythm in patients with paroxysmal atrial fibrillation while also playing a crucial role in preventing a range of ventricular arrhythmias. Amiodarone has a complex pharmacokinetic profile, characterized by a large volume of distribution and a long half-life, which can range from several weeks to months, resulting in prolonged effects even after discontinuation. Side effects may include thyroid dysfunction, pulmonary fibrosis, and hepatic injury, necessitating regular follow-ups. Additionally, amiodarone interacts with several drugs, including anticoagulants, which must be managed to prevent adverse effects. Therefore, a deep understanding of both oral and intravenous formulations, as well as proper dosage adjustments, is essential. The aim of this paper is to provide a comprehensive and updated review on amiodarone's indications, contraindications, recommended dosages, drug interactions, side effects, and monitoring protocols.

Acute hepatotoxicity of intravenous amiodarone in a Becker muscular dystrophy patient with decompensated heart failing and ABCB4 gene mutation: as assessed for causality using the updated RUCAM

BACKGROUND

Cardiac dysfunction, including arrhythmias, may be one of the main clinical manifestations of Becker muscular dystrophy (BMD). Amiodarone is widely used to treat arrhythmia. However, multi-systemic toxicity caused by amiodarone, especially hepatotoxicity, should not be neglected. Here, we introduce a novel case of multi-systemic amiodarone toxicity involving the liver, renal and coagulation in BDM patient with ABCB4 gene mutation.

CASE PRESENTATION

We present a case of a 16-year-old boy admitted with heart failure and atrial fibrillation (AF). He was diagnosed with Becker muscular dystrophy (BMD) and gene testing showed comorbid mutations in gene DMD, ABCB4 and DSC2. Amiodarone was prescribed to control the paroxysmal atrial fibrillation intravenously. However, his liver enzyme levels were sharply elevated, along with cardiac shock, renal failure and coagulation disorders. After bedside continuous renal replacement therapy, the patient's liver function and clinical status rehabilitated.

CONCLUSIONS

ABCB4 gene mutation might be involved in amiodarone-induced hepatotoxicity. Studies in a cohort might help to prove this hypothesis in the future.

A Rare Case of Intravenous Amiodarone Toxicity

Amiodarone is a highly effective treatment for life-threatening supraventricular and ventricular arrhythmias, namely in the setting of acutely decompensated heart failure. However, it could be associated with several serious adverse effects both in long-term oral therapy and in short-term use of intravenous (IV) preparation, including shock and liver injury. We report an unusual case of life-threatening refractory hypotension associated with acute hepatitis and renal failure a few hours after initiation of IV amiodarone. A 70-year-old man was admitted to the emergency department (ED) with dyspnea, chest discomfort, and a non-productive cough. Physical examination and complementary diagnostic tests helped diagnose acutely decompensated heart failure due to atrial fibrillation (AF) with a rapid ventricular response, and IV amiodarone was started. A few hours after initiating this drug, the patient developed hypotension with the need for inotropic therapy, acute elevation of amino transaminases, and renal failure. Renal function and liver transaminases returned to baseline after discontinuing amiodarone. A Roussel Uclaf Causality Assessment Method (RUCAM) score of 5 identifies our patient`s acute hepatitis as a possible adverse drug reaction. Refractory hypotension and liver injury with acute hepatitis after a short-term IV amiodarone therapy are extremely rare with few previously reported cases. Therefore, it is very important to perform continuous hemodynamic monitoring of the patient and liver function monitorization during short-term IV administration of this drug because these complications can be potentially fatal. A high index of suspicion is the key to functional organic recovery.

Prolonged Jaundice Secondary to Amiodarone Use: A Case Report and Literature Review

Adverse reactions to the antiarrhythmic medication amiodarone are severe, potentially life-threatening, and not rare. One in three patients on long-term therapy experience elevated liver enzymes, and clinically apparent liver toxicity occurs in 1% of patients treated. We report the case of a 76-year-old patient with amiodarone-induced intrahepatic cholestasis and prolonged hyperbilirubinemia despite the discontinuation of the offending agent. Current research hypothesizes that amiodarone leads to hepatic injury both by direct hepatotoxicity and by increasing the likelihood of hepatocytes to create abnormal, toxic metabolites. Increased awareness of such an adverse effect can guide clinicians toward the possible underlying etiologies of prolonged jaundice.

Gastrointestinal Side Effects of Antiarrhythmic Medications: A Review of Current Literature

Antiarrhythmic drugs are commonly prescribed cardiac drugs. Due to their receptor mimicry with several of the gastrointestinal tract receptors, they can frequently lead to gastrointestinal side effects. These side effects are the most common reasons for discontinuation of these drugs by the patients. Knowledge of these side effects is important for clinicians that manage antiarrhythmic drugs. This review focuses on the gastrointestinal side effects of these drugs and provides a detailed up-to-date literature review of the side effects of these drugs. The review provides case reports reported in the literature as well as possible mechanisms that lead to gastrointestinal side effects.

Acute Hepatotoxicity of Intravenous Amiodarone: Case Report and Review of the Literature

Amiodarone is a class III antiarrhythmic drug widely used for the treatment of both supraventricular and ventricular arrhythmias in intensive care unit. Hepatotoxicity of amiodarone is usually mild and delayed onset. Acute hepatotoxicity is a rare side effect and usually correlated to intravenous form use. In this case, acute hepatocellular injury occurred within 24 hours after the administration of intravenous amiodarone. Liver enzyme significantly improved after holding intravenous amiodarone use. Because ventricular arrhythmia persisted and side effects occurred to alternative therapy, low dose of oral amiodarone was resumed and hepatotoxicity did not occur afterward. Acute hepatotoxicity of intravenous amiodarone is possibly related to polysorbate 80, the solubilizer of amiodarone infusion or higher dose. As a result, when intravenous amiodarone is prescribed, closely monitoring liver enzyme is highly suggested. If acute hepatitis takes place secondary to intravenous amiodarone, oral therapy should not be resumed afterward. If there is no alternative treatment, lower dose of oral amiodarone (≤200 mg/d) could be tried and should monitor liver function regularly.

Hepatic Dysfunction in Patients Receiving Intravenous Amiodarone

OBJECTIVES

Amiodarone is a commonly used antiarrhythmic drug. Hepatotoxicity following chronic oral administration occurs in 1% to 3% of patients. Hepatotoxicity following intravenous (IV) administration is infrequent but may be associated with dramatic increases in serum transaminases. We describe the incidence of liver toxicity among patients receiving IV amiodarone during a 5-year period.

METHODS

This was a single-center retrospective review of patients receiving IV amiodarone for any cause. The outcome measures were development of elevated serum transaminases and the relation of transaminitis to all-cause 30-day mortality.

RESULTS

A total of 1510 patients received amiodarone intravenously between 2005 and 2011; 77 (5%) developed elevated liver enzymes. Enzyme elevation was divided into mild (100-300 IU/L), moderate (300-1000 IU/L), and severe (>1000 IU/L). The median alanine aminotransferase was 189 (37-10,006) IU/L and aspartate aminotransferase was 253 (84-12,005) IU/L. The 30-day mortality among those with transaminitis was 22%; however, no patient died of amiodarone-related liver disease.

CONCLUSIONS

Amiodarone can cause severe elevation in liver enzymes. The incidence of severe transaminitis is low; deaths following IV amiodarone are rarely caused by drug-induced liver failure.

Predictors of intravenous amiodarone induced liver injury

Background

Intravenous (IV) amiodarone may be associated with liver injury that may necessitate drug discontinuation. The prediction of amiodarone induced liver injury (AILI) and its severity may help careful patient monitoring or the choice of other measures alternative to amiodarone in high risk patients. Little is known regarding predictors of AILI.

Objectives

To address the predictors of AILI and its severity.

Methods

The study included 180 patients indicated for IV amiodarone therapy who were divided into 2 groups: cases (90 patients) who developed AILI, and controls (90 patients) who did not develop AILI. AILI was defined as aminotransferase (ALT and AST) elevation by ⩾2 folds of baseline levels. Severe AILI was defined as enzyme elevation by >5 folds of baseline values.

Results

Multivariate analysis showed that the presence of cardiomyopathy (P = 0.032), congestive hepatomegaly (P = 0.001), increasing baseline total bilirubin (P < 0.0001), direct current cardioversion (P = 0.015), and increasing dose of amiodarone (P = 0.014) to be independent predictors for AILI. Regarding severity of AILI, inotropic support (P = 0.034), congestive hepatomegaly (P = 0.012), increasing baseline total bilirubin (P = 0.001), and increasing dose of amiodarone (P = 0.002) were found to be independent predictors for severe AILI. Among cases, linear regression analysis showed that baseline ALT was the only significant independent predictor of post-amiodarone ALT (P < 0.0001), while baseline AST (P < 0.0001) and EF (P = 0.012) were the only significant independent predictors of post-amiodarone AST.

Conclusions

Compromised cardiac, hepatic, and hemodynamic conditions, with increasing dose of IV amiodarone were associated with AILI. Severity of liver injury had linear relationship with baseline aminotransferase levels and left ventricular systolic function.

Metabolite identification studies on amiodarone in in vitro (rat liver microsomes, rat and human liver S9 fractions) and in vivo (rat feces, urine, plasma) matrices by using liquid chromatography with high-resolution mass spectrometry and multiple-stage mass spectrometry: characterization of the diquinone metabolite supposedly responsible for the drug's hepatotoxicity

RATIONALE

Several mechanisms have been anticipated for the toxicity of amiodarone, such as oxidative stress, lipid peroxidation, phospholipidosis, free radical generation, etc. Amiodarone is structurally similar to benzbromarone, an uricosuric agent, which was withdrawn from European markets due to its idiosyncratic hepatotoxicity. A proposed reason behind the toxicity of benzbromarone was the production of a reactive ortho-diquinone metabolite, which was found to form adducts with glutathione. Therefore, taking a clue that a similar diquinone metabolite of amiodarone may be the reason for its hepatotoxicity, metabolite identification studies were carried out on the drug using liquid chromatography/mass spectrometry (LC/MS) tools.

METHODS

The studies involved in vitro (rat liver microsomes, rat liver S9 fraction, human liver S9 fraction) and in vivo (rat feces, urine, plasma) models, wherein the samples were analyzed by employing LC/HRMS, LC/MS(n) and HDE-MS.

RESULTS AND CONCLUSIONS

A total of 26 metabolites of amiodarone were detected in the investigated in vitro and in vivo matrices. The suspected ortho-diquinone metabolite was one of them. The formation of the same might be an added reason for the hepatotoxicity shown by the drug.

Hyperacute drug-induced hepatitis with intravenous amiodarone: case report and review of the literature

Amiodarone is a benzofuran class III antiarrhythmic drug used to treat a wide spectrum of ventricular tachyarrhythmias. The parenteral formulation is prepared in polysorbate 80 diluent. We report an unusual case of acute elevation of aminotransaminase concentrations after the initiation of intravenous amiodarone. An 88-year-old Caucasian female developed acute hepatitis and renal failure after initiating intravenous amiodarone for atrial fibrillation with a rapid ventricular response in the setting of acutely decompensated heart failure and hepatic congestion. Liver transaminases returned to baseline within 7 days after discontinuing the drug. Researchers hypothesized that this type of injury is related to liver ischemia with possible superimposed direct drug toxicity. The CIOMS/RUCAM scale identifies our patient's acute hepatitis as a highly probable adverse drug reaction. Future research is needed to understand the mechanisms by which hyperacute drug toxicity occurs in the setting of impaired hepatic perfusion and venous congestion.