QT Prolongation and Life Threatening Ventricular Tachycardia in a Patient Injected With Intravenous Meperidine (Demerol®)

The designer benzodiazepine, flubromazepam, induces reward-enhancing and cardiotoxic effects in rodents

The use of many benzodiazepines is controlled worldwide due to their high likelihood of abuse and potential adverse effects. Flubromazepam—a designer benzodiazepine—is a long-acting gamma-aminobutyric acid subtype A receptor agonist. There is currently a lack of scientific evidence regarding the potential for flubromazepam dependence or other adverse effects. This study aimed to evaluate the dependence potential, and cardiotoxicity via confirmation of the QT and RR intervals which are the factors on the electrical properties of the heart of flubromazepam in rodents. Using a conditioned place preference test, we discovered that mice treated intraperitoneally with flubromazepam (0.1 mg/kg) exhibited a significant preference for the flubromazepam-paired compartment, suggesting a potential for flubromazepam dependence. In addition, we observed several cardiotoxic effects of flubromazepam; 100-μM flubromazepam reduced cell viability, increased RR intervals but not QT intervals in the electrocardiography measurements, and considerably inhibited potassium channels in a human ether-à-go-go-related gene assay. Collectively, these findings suggest that flubromazepam may have adverse effects on psychological and cardiovascular health, laying the foundation for further efforts to list flubromazepam as a controlled substance at both national and international levels.

2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH) induce adverse effects on the cardiovascular system

Two new psychoactive substances (NPSs) classified as phenethylamines, namely 2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH), are being abused by people seeking recreational hallucinogens. These NPSs may cause serious health problems as their adverse effects are not known in most cases. Therefore, in the present study, we evaluated the cardiotoxicity of 25I-NBOH and 25C-NBOH using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), Langendorff test, and human ether-a-go-go-related gene (hERG) assay. Furthermore, we analyzed the expression levels of p21 CDC42/RAC1-activated kinase 1 (PAK1), which is known to play various roles in the cardiovascular system. In the MTT assay, treatment with 25I-NBOH or 25C-NBOH dramatically decreased viability of H9c2 cardiomyocytes. Meanwhile, these two compounds significantly increased QT intervals and RR intervals in the rat ECG measurement. 25I-NBOH down-regulated the PAK1 protein expression in rat primary cardiomyocytes as well as H9c2 cells. However, 25C-NBOH had no effect on the PAK1 expression in H9c2 cells. In an in-depth study, 25I-NBOH inhibited potassium channels in the hERG assay, but in ex vivo test, the substance did not affect the left ventricular developed pressure (LVDP) and heart rate of the isolated rat hearts. Taken together, these results suggest that both 25I-NBOH and 25C-NBOH may have adverse cardiovascular effect. Further investigation would be needed to determine which factors mainly influence the relationship between PAK1 expression and cardiotoxicity.

Effects of opioid receptor agonist and antagonist medications on electrocardiogram changes and presentation of cardiac arrhythmia: review article

BACKGROUND/PURPOSE

Mortality associated with prescription opioids has significantly increased over the past few decades and is considered a global pandemic. Prescribed opioids can cause cardiac arrhythmias, leading to fatal outcomes and unexpected death, even in the absence of structural cardiac disease. Despite the extent of cardiac toxicity and death associated with these medications, there is limited data to suggest their influences on cardiac electrophysiology and arrhythmias, with the exception of methadone. The goal of our review is to describe the possible mechanisms and to review the different ECG changes and arrhythmias that have been reported.

METHODS

A literature search was performed using Google Scholar, PubMed, Springer, Ovid, and Science Direct to identify studies that demonstrated the use of prescription opioids leading to electrocardiogram (ECG) changes and cardiac arrhythmias.

RESULTS

Many of the commonly prescribed opioid medications can uniquely effect the ECG, and can lead to the development of various cardiac arrhythmias. One of the most significant side effects of these drugs is QTc interval prolongation, especially when administered to patients with a baseline risk for QTc prolongation. A prolonged QTc interval can cause lethal torsades de pointes and ventricular fibrillation. Obtaining an ECG at baseline, following a dosage increase, or after switching an opioid medication, is appropriate in patients taking certain prescribed opioids. Opioids are often used first line for the treatment of acute and chronic pain, procedural sedation, medication opioid use disorders, and maintenance therapy.

CONCLUSIONS

To reduce the risk of cardiac arrhythmias and to improve patient outcomes, consideration of accurate patient selection, concomitant medications, electrolyte monitoring, and vigilant ECG monitoring should be considered.

2-(2,5-Dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe) and N-(2-methoxybenzyl)-2,5-dimethoxy-4-chlorophenethylamine (25C-NBOMe) induce adverse cardiac effects in vitro and in vivo

Two emerging psychoactive substances, 2-(2,5-dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe) and N-(2-methoxybenzyl)-2,5-dimethoxy-4-chlorophenethylamine (25C-NBOMe), are being abused, leading to fatal and non-fatal intoxications. However, most of their adverse effects have been reported anecdotally. In the present study, cardiotoxicity was evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), and human ether-a-go-go-related gene (hERG) assay. Expression levels of p21 (CDC42/RAC)-activated kinase 1 (PAK1), one of known biomarkers for cardiotoxicity, were also analyzed. Both 25D-NBOMe and 25C-NBOMe at 100 μM reduced cell viability in MTT assay. At 2.0 mg/kg and 0.75 mg/kg, they prolonged QT intervals in rat ECG. PAK1 was down-regulated by treatment with these two test compounds. Furthermore, potassium channels were inhibited by 25D-NBOMe treatment in hERG assay. Taken together, these results suggest that both 25D-NBOMe and 25C-NBOMe have potential cardiotoxicity, especially regarding cardiac rhythm. Further studies are needed to confirm the relationship between PAK1 down-regulation and cardiotoxicity.

Opioids and Cardiac Arrhythmia: A Literature Review

OBJECTIVE

One of the most important side effects of opioids is their influence on the electrical activity of the heart. This review focusses on the effects of opioids on QT interval prolongation and their arrhythmogenic liability.

METHODS

By using various keywords, papers published up to 2018 in different databases were searched and identified. The search terms were opioids names, corrected QT interval, human-ether-a-go-go gene, torsades de pointes (TdP), cardiac arrhythmias, opioid dependence and other relevant terms. It emphasized the effects of each opioid agent alone on electrocardiogram (ECG) and some interactions.

RESULTS

Available data indicate that some opioids such as methadone are high-risk even at low doses, and have potential for prolongation of the QT interval and development of TdP, a dangerous ventricular tachycardia. A number of opioids such as tramadol and oxycodone are intermediate risk drugs and may develop long QT interval and TdP in high doses. Some other opioids such as morphine and buprenorphine are low-risk drugs and do not produce QT interval prolongation and TdP at least in routine doses. Opium-consumers are at higher risk of supra-ventricular arrhythmias, sinus bradycardia, cardiac block and atrial fibrillation.

CONCLUSION

The cardiac arrhythmogenicity of various opioids is different. Methadone has a higher capability to induce long QT interval and dangerous arrhythmias in conventional doses than others. To reduce of arrhythmogenic risk, high doses of opioids must be used cautiously with periodic monitoring of ECG in high-risk consumers such as patients under opioid maintenance treatment.

Simultaneous quantitation of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene in human plasma using solid-phase extraction and gas chromatography/mass spectrometry: Method validation and application to cardiovascular safety of therapeutic doses

RATIONALE

Several opioid analgesics have been related to the prolongation of cardiac repolarization, a condition which can be fatal. In order to establish a correct estimation of the risk/benefit balance of therapeutic doses of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene, it was necessary to develop an analytical method to determinate plasma concentrations of these opioids.

METHODS

Here we describe a method which incorporates strong alkaline treatment to obtain norpropoxyphene amide followed by a one-elution step solid-phase extraction, and without further derivatization. Separation and quantification were achieved by gas chromatography/electron ionization mass spectrometry (GC/EI-MS) in selected-ion monitoring mode. Quantification was performed with 500 μL of plasma by the addition of deuterated analogues as internal standards.

RESULTS

The proposed method has been validated in the linearity range of 25-1000 ng/mL for all the analytes, with correlation coefficients higher than 0.990. The lower limit of quantification was 25 ng/mL. The intra- and inter-day precision, calculated in terms of relative standard deviation, were 2.0-12.0% and 6.0-15.0%, respectively. The accuracy, in terms of relative error, was within a ± 10% interval. The absolute recovery and extraction efficiency ranged from 81.0 to 111.0% and 81.0 to 105.0%, respectively.

CONCLUSIONS

A GC/MS method for the rapid and simultaneous determination of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene in human plasma was developed, optimized and validated. This procedure was shown to be sensitive and specific using small specimen amounts, suitable for application in routine analysis for forensic purposes and therapeutic monitoring. To our knowledge, this is the first full validation of the simultaneous determination of these opioids and their metabolites in plasma samples.

Long QT syndrome: a Korean single center study

The long QT syndrome (LQTS) is a rare hereditary disorder in which affected individuals have a possibility of ventricular tachyarrhythmia and sudden cardiac death. We investigated 62 LQTS (QTc ≥ 0.47 sec) and 19 family members whose genetic study revealed mutation of LQT gene. In the proband group, the modes of presentation were ECG abnormality (38.7%), aborted cardiac arrest (24.2%), and syncope or seizure (19.4%). Median age of initial symptom development was 10.5 yr. Genetic studies were performed in 61; and mutations were found in 40 cases (KCNQ1 in 19, KCNH2 in 10, SCN5A in 7, KCNJ2 in 3, and CACNA1C in 1). In the family group, the penetrance of LQT gene mutation was 57.9%. QTc was longer as patients had the history of syncope (P = 0.001), ventricular tachycardia (P = 0.017) and aborted arrest (P = 0.010). QTc longer than 0.508 sec could be a cut-off value for major cardiac events (sensitivity 0.806, specificity 0.600). Beta-blocker was frequently applied for treatment and had significant effects on reducing QTc (P = 0.007). Implantable cardioverter defibrillators were applied in 6 patients. Congenital LQTS is a potentially lethal disease. It shows various genetic mutations with low penetrance in Korean patients.

Drugs to be avoided in patients with long QT syndrome: Focus on the anaesthesiological management

Long QT syndrome incidence is increasing in general population. A careful pre-, peri- and post-operative management is needed for patients with this syndrome because of the risk of Torsades de Pointes and malignant arrhythmias. The available data regarding prevention of lethal Torsades de Pointes during anesthesia in patients with long QT syndrome is scant and conflicting: only case reports and small case series with different outcomes have been published. Actually, there are no definitive guidelines on pre-, peri- and post-operative anesthetic management of congenital long QT syndrome. Our review focuses on anesthetic recommendations for patients diagnosed with congenital long QT syndrome furnishing some key points for preoperative optimization, intraoperative anesthetic agents and postoperative care plan, which could be the best for patients with c-long QT syndrome who undergo surgery.