Propafenone poisoning--a case report with plasma propafenone concentrations

A Tissue Distribution Study of Propafenone in an Intentional Fatal Poisoning Case

Propafenone (PPF) belongs to the class 1C antiarrhythmics and can cause electrocardiogram-associated adverse/toxic effects. Cases of PPF intoxication are rarely investigated. We developed a novel and selective GC-MS/MS method for the determination of PPF and its tissue distribution in an intentional fatal poisoning case, which is applicable to PPF quantification in the range of therapeutic to lethal concentrations in complex post-mortem samples. A simple and effective sample pretreatment was applied to all analyzed samples. PPF was determined without the need for dilution, even in highly complex samples containing a wide range of analyte concentrations. Quantification was performed using the standard addition method, developed and validated according to the ICH M10 guidelines. The obtained results indicated that the PPF concentration in the serum from blood taken while alive, before therapy, was the highest ever reported in the literature. Despite the intensive therapy after the patients' admission, the PPF concentrations in the lungs, spleen, femoral blood and cardiac blood were fatal or abnormally high. On the other hand, the concentrations in the liver and skeletal muscle were lower or approximately the same as observed in cases with therapeutic doses. To the best of our knowledge, the distribution of PPF has not been investigated in fatal intoxication cases and can be helpful in clinical or forensic toxicology.

Amiodarone but not propafenone impairs bioenergetics and autophagy of human myocardial cells

Cardiac and extra-cardiac side effects of common antiarrhythmic agents might be related to drug-induced mitochondrial dysfunction. Supratherapeutic doses of amiodarone have been shown to impair mitochondria in animal studies, whilst influence of propafenone on cellular bioenergetics is unknown. We aimed to assess effects of protracted exposure to pharmacologically relevant doses of amiodarone and propafenone on cellular bioenergetics and mitochondrial biology of human and mouse cardiomyocytes. In this study, HL-1 mouse atrial cardiomyocytes and primary human cardiomyocytes derived from the ventricles of the adult heart were exposed to 2 and 7 μg/mL of either amiodarone or propafenone. After 24 h, extracellular flux analysis and confocal laser scanning microscopy were used to measure mitochondrial functions. Autophagy was assessed by western blots and live-cell imaging of lysosomes. In human cardiomyocytes, amiodarone significantly reduced mitochondrial membrane potential and ATP production, in association with an inhibition of fatty acid oxidation and impaired complex I- and II-linked respiration in the electron transport chain. Expectedly, this led to increased anaerobic glycolysis. Amiodarone increased the production of reactive oxygen species and autophagy was also markedly affected. In contrast, propafenone-exposed cardiomyocytes did not exert any impairment of cellular bioenergetics. Similar changes after amiodarone treatment were observed during identical experiments performed on HL-1 mouse cardiomyocytes, suggesting a comparable pharmacodynamics of amiodarone among mammalian species. In conclusion, amiodarone but not propafenone in near-therapeutic concentrations causes a pattern of mitochondrial dysfunction with affected autophagy and metabolic switch from oxidative metabolism to anaerobic glycolysis in human cardiomyocytes.

The Effect of CYP2D6 Phenotypes on the Pharmacokinetics of Propafenone: A Systematic Review and Meta-Analysis

Propafenone (PPF) is a class 1C antiarrhythmic agent mainly metabolized by cytochrome (CYP) 2D6, CYP1A2, and CYP3A4. Previous studies have shown that CYP2D6 polymorphism influences the pharmacokinetics (PK) of PPF. However, the small sample sizes of PK studies can lead to less precise estimates of the PK parameters. Thus, this meta-analysis was performed to merge all current PK studies of PPF to determine the effects of the CYP2D6 phenotype more accurately on the PPF PK profile. We searched electronic databases for published studies to investigate the association between the PPF PK and CYP2D6 phenotype. Four PK-related outcomes were included: area under the time–concentration curve (AUC), maximum concentration (Cmax), apparent clearance (CL/F), and half-life (t1/2). A total of five studies were included in this meta-analysis (n = 56). Analyses were performed to compare PK parameters between poor metabolizers (PMs) versus extensive metabolizers (EMs). PPF has a non-linear pharmacokinetics; therefore, analyses were performed according to dose (300 mg and 400 mg). At 300 mg, the AUC mean (95% CI), Cmax, and t1/2 of PPF in PMs were 15.9 (12.5–19.2) µg·h/mL, 1.10 (0.796–1.40) µg/mL, and 12.8 (11.3–14.3) h, respectively; these values were 2.4-, 11.2-, and 4.7-fold higher than those in the EM group, respectively. At 400 mg, a comparison was performed between S- and R-enantiomers. The CL/F was approximately 1.4-fold higher for the R-form compared with the S-form, which was a significant difference. This study demonstrated that CYP2D6 metabolizer status could significantly affect the PPF PK profile. Adjusting the dose of PPF according to CYP2D6 phenotype would help to avoid adverse effects and ensure treatment efficacy.

Propafenone Poisoning of a Female Adolescent After a Suicide Attempt

Propafenone is an antiarrhythmic agent for the management of ventricular and supraventricular tachycardia and atrial fibrillation. Propafenone poisoning is rare but may be life-threatening due to drug-induced arrhythmias. Electrocardiographic changes in PR, QRS, and QT intervals have been recorded. We present a case of a 15-year-old female adolescent who developed arrhythmias and convulsions due to propafenone intoxication, in an attempt to commit suicide. The outcome of the case was a full recovery from the arrhythmias and the seizures. The aim of this article is to highlight the possibility of a lethal intoxication by a common antiarrhythmic drug. Our case aims to present our therapeutic strategy that relies mainly on close monitoring of patients and cardiac output support.

Ventricular Tachycardia Induced by Propafenone Intoxication in a Pediatric Patient

Unintentional poisonings are a global health problem frequently resulting in hospital admissions. Propafenone is a class 1C antiarrhythmic drug used in the second-line management of supraventricular and ventricular arrhythmias and, when unintentionally ingested, can lead to severe and life-threatening poisoning. We describe a case of a 3-year-old male patient unintentionally ingesting 300 mg (20 mg/kg) of propafenone and presenting with ventricular tachycardia with QT prolongation. Two boli of intravenous hypertonic sodium bicarbonate (total amount of 3 mEq/kg), followed by 3-hours continuous infusion of 1 mEq kg h sodium bicarbonate, were able to restore the clinical conditions of the patient. With this case report, we aim to highlight the existing challenge in the therapeutic management of propafenone intoxication that finds intravenous hypertonic bicarbonate to be a useful tool also in pediatric population.

Propafenone-associated Gross Hematuria: A Case Report and Review of the Literature

PURPOSE

Propafenone hydrochloride has been widely used for the treatment of supraventricular and ventricular arrhythmias. We present a case report of an 81-year-old patient with propafenone-associated gross hematuria.

METHODS

The Naranjo Adverse Drug Reaction Probability Scale was used to assess causality. We also performed a literature search to find publications that report propafenone-associated gross hematuria.

FINDINGS

The Naranjo scale generated a score of 6, suggesting a probable association between gross hematuria and propafenone therapy. Thirteen publications that reported an association between gross hematuria and propafenone administration were found.

IMPLICATIONS

A probable association exists between gross hematuria and propafenone.

Pediatric extracorporeal cardiopulmonary resuscitation settled in an emergency department for a propafenone intentional intoxication

The use of drugs in suicide attempts is becoming more and more frequent among adolescents. Intentional intoxication with propafenone is very rare and mainly reported in adults associated with other drugs. The therapeutic approach is symptomatic, since there is no specific antidote for propafenone. We present a pediatric case of intentional ingestion of 1.8 g of propafenone that caused refractory cardiogenic shock. The patient was successfully rescued with extracorporeal cardiopulmonary resuscitation in the emergency department of a secondary level peripheral hospital.

Full recovery after prolonged resuscitation from cardiac arrest due to propafenone intoxication: A case report

RATIONALE

The prognosis of cardiac arrest (CA) induced by propafenone intoxication was thought to be very poor. The maximal duration of cardiopulmonary resuscitation (CPR) for propafenone induced CA is unknown.

PATIENT CONCERNS

We describe a case that was successfully resuscitated after prolonged CPR (totaling 340 minutes during one hospital visit) for propafenone intoxication without subsequent neurological sequela.

DIAGNOSES

A previously healthy 36-year-old female who developed multiple and prolonged CAs after consuming 98 tablets of 50mg propafenone. The CPR duration of this case, to the best of our knowledge, is the longest of all existing propafenone-induced CPR events to still have full recovery. We also analyse the contributing factors to this successful CPR.

INTERVENTIONS

Sodium bicarbonate, inotropic drugs and pacemaker application did not prevent the occurrence of CA. A full recovery was eventually achieved after prolonged CPR with a mechanical CPR device, blood purification and other aggressive supportive treatments.

OUTCOMES

Full recovery without neurological sequela.

LESSONS

Prolonged CPR including the application of mechanical CPR devices should be considered in propafenone-related CA, especially in young patients without significant comorbidities and delayed resuscitation.

Successful treatment of propafenone-induced cardiac arrest by calcium gluconate

Propafenone is prescribed for the control of cardiac ventricular arrhythmias. Poisoning from propafenone intoxication is rare, but the survival rate of patients is low. We present a case of a 37-year-old man who developed cardiac arrest due to propafenone intoxication. Cardiopulmonary resuscitation, plasmapheresis, and other medical treatments had no effect on cardiac arrest. After repeated administrations of calcium gluconate, the patient achieved a full recovery. To the best of our knowledge, this is the first case report in which a full recovery from cardiac arrest was achieved by administration of calcium gluconate. We recommend that for patients poisoned by propafenone, close monitoring for decreased blood calcium is important.

Effect of CYP2D6 polymorphisms on the pharmacokinetics of propafenone and its two main metabolites

AIM OF THE STUDY

Propafenone (PPF) is an antiarrhythmic drug, metabolized mainly by CYP2D6 to 5-hydroxypropafenone (5OH-PPF) and by CYP3A4 to norpropafenone (NOR-PPF). CYP2D6 shows a high degree of genetic polymorphism which is associated with diminished antiarrhythmic efficacy or cardiac seizures/cardiotoxicity. This study aimed to investigate the effect of the CYP2D6 polymorphism on the pharmacokinetics of PPF and its two main metabolites. The usefulness of PPF/5OH-PPF ratio for CYP2D6 phenotyping in healthy adults was also evaluated.

METHODS

Twelve healthy volunteers, 3 poor metabolizers (PM), 2 intermediate metabolizers (IM) and seven extensive metabolizers (EM) received an oral dose of PPF. Concentrations of PPF and its metabolites were analyzed in serum samples over 27h.

RESULTS

The PPF/5OH-PPF ratio distinguished EMs from PMs, but not from IMs. In PMs, the mean transit time (MTT) values were almost the same for PPF and NOR-PPF and much higher than those of EMs and IMs. 5OH-PPF was not detected in EMs. Mean MTT values of 5OH-PPF and NOR-PPF in IMs were 5.27- and 1.52-fold higher than those of EMs.

CONCLUSION

A single time point serum PPF-MR approach is a useful tool to identify PMs. CYP2D6 polymorphism significantly affects the pharmacokinetics of PPF and its two metabolites.

Predicting adverse side effects of drugs

Background

Studies of toxicity and unintended side effects can lead to improved drug safety and efficacy. One promising form of study comes from molecular systems biology in the form of "systems pharmacology". Systems pharmacology combines data from clinical observation and molecular biology. This approach is new, however, and there are few examples of how it can practically predict adverse reactions (ADRs) from an experimental drug with acceptable accuracy.

Results

We have developed a new and practical computational framework to accurately predict ADRs of trial drugs. We combine clinical observation data with drug target data, protein-protein interaction (PPI) networks, and gene ontology (GO) annotations. We use cardiotoxicity, one of the major causes for drug withdrawals, as a case study to demonstrate the power of the framework. Our results show that an in silico model built on this framework can achieve a satisfactory cardiotoxicity ADR prediction performance (median AUC = 0.771, Accuracy = 0.675, Sensitivity = 0.632, and Specificity = 0.789). Our results also demonstrate the significance of incorporating prior knowledge, including gene networks and gene annotations, to improve future ADR assessments.

Conclusions

Biomolecular network and gene annotation information can significantly improve the predictive accuracy of ADR of drugs under development. The use of PPI networks can increase prediction specificity and the use of GO annotations can increase prediction sensitivity. Using cardiotoxicity as an example, we are able to further identify cardiotoxicity-related proteins among drug target expanding PPI networks. The systems pharmacology approach that we developed in this study can be generally applicable to all future developmental drug ADR assessments and predictions.

Usefulness of postmortem biochemistry in forensic pathology: illustrative case reports

The aim of this work is to present some practical, postmortem biochemistry applications to illustrate the usefulness of this discipline and reassert the importance of carrying out biochemical investigations as an integral part of the autopsy process. Five case reports are presented pertaining to diabetic ketoacidosis in an adult who was not known to suffer from diabetes and in presence of multiple psychotropic substances; fatal flecainide intoxication in a poor metabolizer also presenting an impaired renal function; diabetic ketoacidosis showing severe postmortem changes; primary aldosteronism presented with intracranial hemorrhage and hypothermia showing severe postmortem changes. The cases herein presented can be considered representative examples of the importance of postmortem biochemistry investigations, which may provide significant information useful in determining the cause of death in routine forensic casework or contribute to understanding the pathophysiological mechanisms involved in the death process.