Elderly patients with suspected chronic digoxin toxicity: A comparison of clinical characteristics of patients receiving and not receiving digoxin-Fab

Antidote use for cardiac arrest or hemodynamic instability due to cardiac glycoside poisoning: A narrative review

Introduction

Cardiac glycosides comprise medications such as digoxin and digitoxin, plants, and even certain toad venoms. Intoxication with cardiac glycosides can lead to hemodynamic instability and cardiac arrest. With this narrative review, our objective was to determine if any therapy used in a near-cardiac arrest state due to cardiac glycoside poisoning could improve survival with favourable functional and neurological outcomes.

Methods

We searched the Medline, PubMed, EMBASE and Cochrane Library databases up to February 2022 for controlled trials, observational studies, and case reports. We reviewed studies if participants were exposed to a cardiac glycoside, had hemodynamic instability, and an intervention was attempted to reverse the toxicity. The effect of interventions on (1) survival with favourable functional and neurological outcomes and (2) correction of hemodynamic instability was assessed.

Results

Of the 2422 studies found, 73 were included for analysis, of which 58 were case reports or series, and 15 were observational cohorts. Most patients were intoxicated with medication (60 individual cases and 11 observational cohorts). Administration of digoxin immune-Fab fragments was associated with improved hemodynamic status and survival in medication patients. Administration of magnesium, cardioversion, and cardiac pacing was associated with favourable outcomes, while administration of atropine, antiarrhythmics, or calcium was not.

Conclusion

In patients with hemodynamic instability due to cardiac glycoside intoxication, digoxin immune-Fab fragments should be given, and magnesium administration, cardioversion, and cardiac pacing can reasonably be attempted.

Characterizing Utilization and Outcomes of Digoxin Immune Fab for Digoxin Toxicity

BACKGROUND

Digoxin is a widely prescribed drug for congestive heart failure and atrial fibrillation. Digoxin has a narrow therapeutic index and toxicity can develop quite easily. Digoxin immune fab (DIF) is an effective treatment for toxicity, however there are limited studies characterizing its impact on clinical outcomes in real-world clinical practice.

OBJECTIVES

The aim of this study was to identify factors and healthcare outcomes associated with digoxin immune fab (DIF) treatment in patients with confirmed/suspected digoxin toxicity.

METHODS

An IRB-approved retrospective chart review of digoxin toxic patients (2011-2020) presenting at an academic healthcare system was conducted. Demographic and clinical data were collected. Patients were stratified by DIF treatment versus non-DIF treatment. DIF utilization patterns (appropriate, use when not indicated, or underutilized) were determined using pre-defined criteria. Severe digoxin toxicity was defined as having one or more of the following: mental status disturbances, antiarrhythmic therapy, acute renal impairment or dehydration, serum digoxin concentration (SDC) > 4 ng/mL, or serum K+ > 5 mEq/mL. Logistic multivariable regression analysis evaluated factors associated with DIF use. All statistical analyses were performed in R version 4.1.

RESULTS

Data from 96 patients (non-DIF treated group = 49; DIF treated group = 47) were analyzed. DIF was used appropriately in 70 patients (73%), underutilized in 19 (20%), and administered to 7 (7%) patients when it was not indicated. Several clinical parameters differentiated the DIF from the non-DIF group (p < 0.05) including higher mean SDC (3.41 ± 1.63 vs 2.87 ± 1.17), higher mean potassium (5.33 ± 1.48 vs 4.55 ± 0.87), more toxicity severity (85% vs 49%), and more likely to require cardiac pacing (26% vs 4%). Digoxin toxicity resolved sooner in the DIF group (coefficient - 0.702, 95% CI - 1.137 to - 0.267) (p < 0.01) and they had shorter intensive care unit lengths of stay (12.4 ± 20.3 vs 24.4 ± 28.7 days; p = 0.018). The all-cause mortality rate in patients appropriately managed with DIF therapy versus those patients where DIF was underutilized was 11% and 21%, respectively.

CONCLUSIONS

Based on our study population, DIF therapy appears to be beneficial in limiting duration of toxicity and intensive care unit lengths of stay in digoxin toxic patients. Although DIF was appropriately utilized in most cases, there was a relatively high proportion of cases in which DIF treatment was either underutilized or not indicated.

Diagnosis and practical management of digoxin toxicity: a narrative review and consensus

There are currently no universally accepted guidelines for the management of digoxin toxicity. In the absence of clinical practice guidelines, a set of consensus recommendations for management of digoxin toxicity in the clinical setting were developed through a modified Delphi approach. The recommendations highlight the importance of early recognition of signs of potentially life-threatening toxicity that requires immediate treatment with digoxin-specific antibodies. The consensus identifies a straightforward approach to dosing immune antibody fragments according to the presence or absence of signs of life-threatening toxicity. Supportive measures and management of specific signs of toxicity are also covered.

A Case of Digoxin Toxicity Due to Acute Renal Failure

Since the publication of the Digitalis Investigation Group trial in 1997, digoxin use has declined significantly. Medications such as angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs) and beta-blockers that have been demonstrated to have a decrease in morbidity and mortality are prescribed in favor of digoxin. Despite the reduction in digoxin use and improved therapeutic monitoring, digoxin toxicity remains a significant cause of morbidity and mortality. When digoxin toxicity is suspected, patients should be managed with supportive care, including discontinuation of the medication, and consideration for administration of digoxin-specific antibody fragment. We present a case of digoxin toxicity precipitated by acute renal failure, with a discussion on the pathophysiology and diagnosis of digoxin toxicity, along with the indications for administration of digoxin-specific antibody fragments. While digoxin toxicity is prescribed less commonly, physicians need to maintain a high index of suspicion and be comfortable with administering digoxin-specific antibody fragment in these scenarios.

The inhibition mechanism of luteolin on peroxidase based on multispectroscopic techniques

Luteolin, a plant-derived flavonoid, was found to exert effective inhibitory effect to peroxidase activity in a non-competitive manner with an IC50 of (6.62 ± 0.45) × 10-5 mol L-1. The interaction between luteolin and peroxidase induced the formation of a static complex with a binding constant (Ksv) of 7.31 × 103 L mol-1 s-1 driven by hydrogen bond and hydrophobic interaction. Further, the molecular interaction between luteolin and peroxidase resulted in intrinsic fluorescence quenching, structural and conformational alternations which were determined by multispectroscopic techniques combined with computational molecular docking. Molecular docking results revealed that luteolin bound to peroxidase and interacted with relevant amino acid residues in the hydrophobic pocket. These results will provide information for screening additional peroxidase inhibitors and provide evidence of luteolin's potential application in preservation and processing of fruit and vegetables and clinical disease remedy.

Digitoxigenin presents an effective and selective antileishmanial action against Leishmania infantum and is a potential therapeutic agent for visceral leishmaniasis

Treatment for visceral leishmaniasis (VL) is hampered mainly by drug toxicity, their high cost, and parasite resistance. Drug development is a long and pricey process, and therefore, drug repositioning may be an alternative worth pursuing. Cardenolides are used to treat cardiac diseases, especially those obtained from Digitalis species. In the present study, cardenolide digitoxigenin (DIGI) obtained from a methanolic extract of Digitalis lanata leaves was tested for its antileishmanial activity against Leishmania infantum species. Results showed that 50% Leishmania and murine macrophage inhibitory concentrations (IC₅₀ and CC₅₀, respectively) were of 6.9 ± 1.5 and 295.3 ± 14.5 μg/mL, respectively. With amphotericin B (AmpB) deoxycholate, used as a control drug, values of 0.13 ± 0.02 and 0.79 ± 0.12 μg/mL, respectively, were observed. Selectivity index (SI) values were of 42.8 and 6.1 for DIGI and AmpB, respectively. Preliminary studies suggested that the mechanism of action for DIGI is to cause alterations in the mitochondrial membrane potential, to increase the levels of reactive oxygen species and induce accumulation of lipid bodies in the parasites. DIGI was incorporated into Pluronic® F127-based polymeric micelles, and the formula (DIGI/Mic) was used to treat L. infantum–infected mice. Miltefosine was used as a control drug. Results showed that animals treated with either miltefosine, DIGI, or DIGI/Mic presented significant reductions in the parasite load in their spleens, livers, bone marrows, and draining lymph nodes, as well as the development of a specific Th1-type response, when compared with the controls. Results obtained 1 day after treatment were corroborated with data corresponding to 15 days after therapy. Importantly, treatment with DIGI/Mic induced better parasitological and immunological responses when compared with miltefosine- and DIGI-treated mice. In conclusion, DIGI/Mic has the potential to be used as a therapeutic agent to protect against L. infantum infection, and it is therefore worth of consideration in future studies addressing VL treatment.

An analysis of fatal iatrogenic therapeutic errors reported to United States poison centers

OBJECTIVE

This is a descriptive study evaluating fatal iatrogenic and in-hospital medication errors reported to United States poison centers.

METHODS

A retrospective evaluation of the National Poison Data System from 2000-2017 of all therapeutic errors with a scenario coded as iatrogenic/healthcare professional or occurring in a healthcare facility. Death abstracts were reviewed for details of the exposure and therapeutic error scenarios were recoded or added to the case as appropriate. Cases, where death was considered not related to the exposure, were excluded. Additionally, we created one additional scenario (rate-related) and one additional route of administration (intrathecal) to better describe the cases.

RESULTS

A total of 172 cases were evaluated. The majority of the patients were female (52.3%) with a median age of 58.5 years (range: 2 days to 96 years). The most commonly reported medication error was "other incorrect dose" (22.7%) followed by other/unknown error (15.1%). The route of exposure was primarily parenteral (54.9%), followed by ingestion (30.2%), then intrathecal (7.0%). The most common medications were cardiac drugs, chemotherapeutics, opioids, anticoagulants, and sedative-hypnotic/antipsychotics.

CONCLUSIONS

Iatrogenic and in-hospital medication errors have been studied extensively with goals to reduce their occurrence. Specific controls to prevent incorrect dosing routes, 10-fold overdoses, and incorrect intrathecal administration have been instituted. Despite interventions, all three of these therapeutic errors continued to occur in 2017, suggesting that more preventive controls should be instituted.