Dose Of Digoxin Research Articles

Physiologically Based Pharmacokinetic Modeling to Assess Ritonavir-Digoxin Interactions and Recommendations for Co-Administration Regimens.

Digoxin is a commonly used cardiac glycoside drug in clinical practice, primarily transported by P-glycoprotein (P-gp) and susceptible to the influence of P-gp inhibitors/inducers. Concurrent administration of ritonavir and digoxin may significantly increase the plasma concentration of digoxin. Due to the narrow therapeutic window of digoxin, combined use may lead to severe toxic effects. Utilize a Physiology-Based Pharmacokinetic (PBPK) model to simulate and predict the impact of the interaction between ritonavir and digoxin on the pharmacokinetics (PK) of digoxin, and provide recommendations for the combined medication regimen. Using PK-Sim®, develop individual PBPK models for ritonavir and digoxin. Simulate the exposure in a drug-drug interaction (DDI) scenario by implementing ritonavir's inhibition of P-glycoprotein (P-gp) on digoxin. Evaluate the performance of the models by comparing the predicted and observed plasma concentration-time curves and predicted versus observed PK parameter values. Finally, adjust the dosing regimen for the combined therapy based on the changes in exposure. According to the model simulations, the steady-state exposure of digoxin increased by 86.5% and 90.2% for oral administration, and 80.2% and 90.2% for intravenous administration, respectively, when 0.25mg or 0.5mg of digoxin was administered concurrently with ritonavir. By reducing the dose of digoxin by 45% or doubling the oral administration interval, similar steady-state concentrations can be achieved compared to when the drugs are not co-administered. In clinical practice, the influence of drug interactions on the plasma concentration changes of digoxin within the body should be considered to ensure the safety and effectiveness of treatment.

Digoxin loading doses for atrial fibrillation in critically Ill patients

Abstract Introduction The use of digoxin, a cardiac glycoside, for inotropic effects and electrophysiologic actions date back as far as the 18th century. Loading doses (LD) of digoxin are recommended when used for rate control in the setting of atrial fibrillation or atrial flutter (AF/AFL), though the optimal serum drug concentration (SDC) remains unknown. Pharmacokinetic based formulas used to calculate a LD target a SDC of 0.8-1.2 ng/mL. Still, digoxin pharmacokinetics remain unpredictable and are influenced by age, weight, renal impairment, and critical illness. Purpose The purpose of this study was to assess the safety and efficacy of digoxin LD used in critically ill patients to rate control AF/AFL and to assess the SDC achieved after a LD. Methods We conducted an Institutional Review Board approved retrospective cohort study at New York University Langone Health between January 2013 and March 2018. Adult patients (18 years of age or older) were included if they received an intravenous digoxin LD for AF/AFL in any intensive care unit and had a digoxin SDC measured between 6 and 24 hours after the LD. Patients were excluded if they received the LD orally. The primary endpoint was the SDC achieved after the LD. Secondary safety endpoints were the incidence of supratherapeutic digoxin SDC (> 1.2 ng/mL). Secondary efficacy endpoints included the incidence of rate control success, defined as a heart rate (HR) less than 110 beats per minute (bpm) within 24 hours of the digoxin LD. Results A total of 92 patients were included in the final analysis. The cohort was 53% male with a median age of 72 years, median BMI of 27, a median creatinine clearance (CrCL) of 47 mL/min at the time of IV digoxin LD and 66% of the cohort had AF. The highest HR associated with the AF/AFL 24 hours prior to digoxin was 133 (121, 145) bpm. The median total LD of digoxin for the entire cohort was 11 mcg/kg (750 mcg). In those with impaired renal function (CrCl < 30 mL/min), the median LD of digoxin was 8.3 mcg/kg. For 61% of the cohort, the LD was distributed over 6-hour intervals. The median SDC after completion of the IV digoxin LD was 1.3 ng/mL (0.9, 1.7), with a range of 0.4-4.1 ng/mL. A SDC > 1.2 ng/mL was observed in 51% of the cohort. Secondary outcomes of rate control success occurred in 60% of the cohort. No patients experienced any digoxin associated dysrhythmias or required reversal. Conclusion We found a SDC of 1.3 ng/mL post a digoxin LD in critically ill patients with AF/AFL to be successful in achieving rate control in 60% of our cohort. Despite 51% of the cohort achieving a SDC > 1.2 ng/mL, digoxin related adverse events were uncommon. Our analysis support previous data suggesting dose adjustment of digoxin in patients with impaired renal function but suggest a higher SDC may be acceptable in the acute setting when used for rate control. Our sample size is limited, and future studies should confirm our findings in critically ill patients.

Efficacy and safety of low-dose digoxin in patients with heart failure. Rationale and design of the DECISION trial.

Digoxin is the oldest drug in cardiovascular (CV) medicine, and one trial conducted >25 years ago showed a reduction in heart failure (HF) hospitalizations but no effect on mortality. However, later studies suggested that the dose of digoxin used in that trial (and other studies) may have been too high. The DECISION (Digoxin Evaluation in Chronic heart failure: Investigational Study In Outpatients in the Netherlands) trial will examine the efficacy and safety of low-dose digoxin in HF patients with reduced or mildly reduced left ventricular ejection fraction (LVEF) with a background of contemporary HF treatment. The DECISION trial is a randomized, double-blind, parallel-group, placebo-controlled event-driven outcome trial which will investigate the efficacy and safety of low-dose digoxin in patients with chronic HF and LVEF <50%. Both patients with sinus rhythm and atrial fibrillation will be enrolled and will be randomized (1:1) to low-dose digoxin or matching placebo. To maintain a target serum digoxin concentration of 0.5-0.9 ng/ml, dose adjustments are made throughout follow-up based on serum digoxin measurements with dummy values for the placebo group. The primary endpoint is a composite of CV mortality and total HF hospitalizations or total urgent hospital visits for worsening HF, and all endpoints are adjudicated blindly by a Clinical Event Committee. The estimated sample size was 982 patients who will be followed for a median of 3 years, and in December 2023 enrolment was completed after 1002 patients. The DECISION trial will provide important evidence regarding the effect of (low-dose) digoxin on CV mortality and total HF hospitalizations and urgent hospital visits when added to contemporary HF treatment of patients with reduced or mildly reduced LVEF. ClinicalTrials.gov identifier: NCT03783429.

Digoxin treatment does not reinduce radioiodine uptake in radioiodine refractory non-medullary thyroid carcinoma.

Patients with non-medullary thyroid carcinoma (NMTC) that are refractory to radioactive iodine (RAI) have a poor prognosis. Strategies for restoring the ability to take up iodine, so-called redifferentiation, are promising but not suitable for all patients. Preclinical studies, in human cell lines just as in a murine model, have shown that the cardiac glycoside digoxin restored RAI uptake. This prospective single-center open-label study aimed to investigate whether treatment with digoxin could reinduce clinically relevant RAI uptake in patients with metastasized RAI-refractory NMTC. Eight patients with metastasized RAI-refractory NMTC were included between November 2022 and June 2023. Before treatment, a baseline [123I]NaI scintigraphy was performed. Thereafter, patients were treated with digoxin for 3 weeks. Starting doses depended on age and weight. For safety reasons, the usual therapeutic range was aimed for. After 1 week, the digoxin plasma concentration was measured, and the digoxin dose was adjusted if necessary. After 3 weeks of digoxin treatment, a second [123I]NaI scintigraphy was performed. RAI uptake was compared between the two scintigraphies. Seven patients completed the digoxin treatment and were evaluable. None of the seven patients showed clinically relevant RAI uptake after digoxin treatment. No digoxin-related serious adverse events occurred during this trial. Contrary to results from preclinical trials, in this trial, 3 weeks of digoxin treatment did not reinduce RAI uptake in patients with NMTC. This highlights essential challenges regarding the approach toward optimization of studies aimed to restore the RAI uptake and its therapeutic efficacy through drug repurposing.

A case report on digoxin toxicity

Digoxin is an inotropic drug that is commonly prescribed in patient with heart related diseases. The effective dose of digoxin is 0.8-2.0 ng/ml beyond which digoxin causes toxic effects like visual dysfunction, irregular heartbeat, and cardiovascular collapse. Digoxin toxicity is caused due to increased automaticity and inotropy due to intracellular calcium and decreased dromotropy due to poisoning of sodium potassium transporter and AV nodal blockade. Digoxin toxicity should be assessed by continuous hemodynamic and cardiac monitoring including 12-lead electrocardiogram. There should be timely and immediate evaluation of electrolyte levels like potassium, calcium, serum creatinine and digoxin levels and prompt intensive care unit admission, if necessary. In this case study we studied a 43 old female patient prescribed with digoxin 0.25 mg, who had a medical history of congestive cardiac failure presented with symptoms of digoxin toxicity. The patient was assessed with electrocardiography (ECG) and managed by keeping digoxin on hold and effective patient counselling.

Safety profile of intravenous digoxin in Chinese patients with acute heart failure with reduced ejection fraction: a small-scale prospective cohort study.

Background: Adverse effects of intravenous digoxin vary from patients and disease status, which should be closely monitored. Aims: To explore the safety profile of intravenous digoxin in acute heart failure with reduced ejection fraction (HFrEF) among Chinese patients. Methods: A clinical prospective, single-center, single-arm, open-label exploratory clinical trial was performed in patients with acute HFrEF at Wuhan Asia Heart Hospital. A fixed dose of 0.5mg digoxin was used intravenously once per day for 3days. The normalized dosage of digoxin (NDD), toxic serum digoxin concentration (SDC), and adverse reactions of intravenous digoxin were recorded. Results: A total of 40 patients were recruited in the study. The SDC increased from 1.03 ± 0.34ng/mL to 1.95 ± 0.52ng/mL during treatment. 50% (20/40) patients reached a toxic SDC of 2.0ng/mL, and toxic effects were seen in 30% (12/40) patients. Estimated glomerular filtration rate (eGFR) < 60mL/min [HR: 5.269; 95% CI: 1.905-14.575, p = 0.001], NDD ≥7μg/kg [HR: 3.028; 95% CI: 1.119-8.194, p = 0.029], and ischemic cardiomyopathy [HR: 2.658; 95% CI: 1.025-6.894, p = 0.044] were independent risk factors for toxic SDC. Toxic SDC was effectively identified [area under the receiver operating characteristic (ROC) curve = 0.85, p < 0.001] using this model, and patients would have a higher risk of toxicity with more risk factors. Conclusion: Intravenous digoxin of 0.5mg was safe and effective for initial dose but not suitable for maintenance treatment in Chinese patients with acute HFrEF. Patients who had lower eGFR, received higher NDD, and had ischemic cardiomyopathy should be closely monitored to avoid digoxin toxicity.

Xinyang tablet ameliorates sepsis-induced myocardial dysfunction by regulating Beclin-1 to mediate macrophage autophagy and M2 polarization through LncSICRNT1 targeting E3 ubiquitin ligase TRAF6

ObjectiveXinyang Tablet (XYT) has emerged as a potential intervention to counter sepsis-induced myocardial dysfunction (SMID) by influencing macrophage autophagy and M2 polarization. This study aimed to unravel the underlying mechanism of XYT in sepsis-induced myocardial dysfunction (SIMD).MethodsA microarray analysis was employed to explore sepsis-related changes, and bioinformatics analysis was used to predict lncRNAs binding to tumor necrosis factor receptor-associated factor 6 (TRAF6). This studio utilized SIMD mouse models induced by lipopolysaccharide (LPS) injection, followed by treatments involving varied doses of XYT, digoxin (positive control), or si-LncSICRNT1. After seven days, evaluations encompassing mouse hair/mental state/diet/weight were measured, and cardiac function via echocardiography were conducted. Myocardial tissue changes were observed using hematoxylin–eosin staining. Additionally, bone marrow-derived macrophages (BMDMs) subjected to LPS for M1 polarization were treated with oe-LncSICRNT1, si-TRAF6 and their negative control, XYT, or autophagy inhibitor 3-Methyladenine (3-MA) (positive control). RT-qPCR and Western blot analyses were employed to assess LncSICRNT1, TRAF6, Beclin-1, LC3II/LC3I, and p62 levels. Immunohistochemistry and flow cytometry were used for M1/M2 polarization markers, while enzyme-linked immunosorbent assay (ELISA) gauged inflammatory factor levels. Interaction between TRAF6 and LncSICRNT1 was probed using RNA pull-down and RNA immunoprecipitation (RIP) assays.ResultsChip analysis obtained 1463 differentially expressed lncRNAs, including LINC01550 (LncSICRNT1). Further prediction indicated that LncSICRNT1 was highly likely to directly bind to TRAF6. XYT treatment in LPS-induced SIMD mice led to notable enhancements in sleep/hair/diet/activity, increased weight/left ventricular end-diastolic diameter (LVEDd)/LV ejection fraction (LVEF)/LV fraction shortening (LVFS). These improvements were associated with elevated LncSICRNT1 expression and decreased TRAF6 protein levels, culminating in reduced myocardial inflammatory responses and improved cardiac function. Notably, XYT was found to suppress macrophage M1 polarization, while enhancing M2 polarization, ultimately benefitting cardiac function via LncSICRNT1 modulation. Furthermore, the study revealed LncSICRNT1 modulated Beclin-1 ubiquitination and restrained macrophage autophagy by targeting TRAF6 expression.ConclusionThe study highlights XYT’s potential to ameliorate LPS-induced SIMD by elevating LncSICRNT1 expression, influencing TRAF6 expression, and regulating Beclin-1 ubiquitination. These actions collectively inhibit macrophage autophagy and foster M1/M2 polarization, contributing to cardiac function improvement.

Population Pharmacokinetics of Digoxin in Nonagenarian Patients: Optimization of the Dosing Regimen.

The aim of this study was to develop a population pharmacokinetic model of digoxin in patients over 90 years old and to propose an equation for adjusting digoxin dose in this population. We included 326 nonagenarian patients admitted to Severo Ochoa University Hospital (Spain) who received digoxin and were under therapeutic drug monitoring. All data were retrospectively collected, and population modeling was performed with non-linear mixed-effect modeling software (NONMEM®). One- and two-compartment models were tested to calculate digoxin clearance (Cl), volume of distribution (Vd), absorption rate constant (Ka), and bioavailability (bioavailable fraction, F). The covariates were evaluated by stepwise covariate model building, and the final model was internally validated by bootstrap analysis with 1000 resamples. External validation was performed with another population of 95 patients with the same characteristics as the modeling group. The population was 26% males, with a mean age of 93.2 years (90-103 years), mean creatinine 1.11 mg/dL (0.42-3.81 mg/dL), and mean total body weight 61.2 kg (40-100 kg). The pharmacokinetics of digoxin were best described by a one-compartment model (ADVAN2 TRANS2), with first-order conditional estimation with interaction. The covariates with influence on our model were creatinine clearance based on the Cockcroft-Gault equation (CG), serum potassium (K), co-administration of loop diuretics, and sex: Cl/F = 4.55 · (CG/36.4)0.468 · 0.83LD · 1.21SEX; Vd/F = 355 · (K/4.3)-0.849; Ka = 1.22 h-1 [where LD indicates loop diuretics (1 for administered, 0 for otherwise) and SEX indicates patient sex (1 for male, 0 for female)]. Based on our results, we proposed an equation to adjust the digoxin dosing regimen in nonagenarian patients: dose (mg) = 0.144 · (CG/36.4)0.468 · 0.83LD · 1.21SEX. The greatest influence on digoxin clearance came from renal function calculated by the Cockcroft-Gault equation. Vd was decreased by K. The model developed showed a precise predictive performance to be applied for therapeutic drug monitoring.

Fundus autofluorescence, optical coherence tomography and electroretinography abnormalities in a patient with digoxin retinopathy that resemble those in KCNV2-associated retinopathy.

Digoxin related retinal toxicity causes blurred vision, photophobia, central scotoma, color vision abnormality, and electroretinography (ERG) abnormalities. Here, we report a case with transient abnormalities in vison, in which fundus autofluorescence (FAF), optical coherence tomography (OCT), and ERG findings resembled those in KCNV2 (potassium voltage-gated channel modifier subfamily V member 2)-associated retinopathy. An 89-year-old woman presented with complaints of acute blurred vision, nyctalopia, photophobia, and color vision abnormality. She received digoxin for tachycardia induced by atrial fibrillation for a month. The fundi showed a faint white ring at the fovea, which showed hyperfluorescence in FAF. OCT showed a thickened EZ in the macula. A dark-adapted (DA)-30 ERG showed a reduced and "squaring (trough-flattened)" a-wave, and a delayed, supernormal b-wave, resulting in a high b/a-wave amplitude ratio. The digoxin dose was reduced following an elevation in serum levels. Five weeks later, her visual acuities improved, and abnormal hyperfluorescence on FAF disappeared. After 6months, no visual symptoms were reported. The ellipsoid-zone thickening in OCT improved; however, the b/a-wave amplitude ratio on DA-30 ERG remained high. The b-wave in LA-long-flash ERG was initially reduced, which improved after correction of serum level of digoxin. The patient's clinical findings resembled those of patients with KCNV2-associated retinopathy or temporal hyperkalemia. These disorders appear to have a common pathogenesis, which may be related to abnormal extracellular potassium levels in the retina. The on-bipolar cells seemed to be more affected than the off-bipolar cells in digoxin related retinal toxicity.

Dosage Optimization of Digoxin in Older Patients with Heart Failure and Chronic Kidney Disease: A Population Pharmacokinetic Analysis.

Renal function is an important index for digoxin dose adjustment, especially in patients with chronic kidney disease (CKD). Decreased glomerular filtration rate is common in older patients with cardiovascular disease. The aim of this study was to establish a digoxin population pharmacokinetic model in older patients with heart failure and CKD and to optimize the digoxin dose strategy. Older patients with heart failure and CKD aged > 60years from January 2020 to January 2021 and who had an estimated glomerular filtration rate (eGFR) < 90mL/min/1.73m2 or urine protein production were enrolled in this retrospective study. Population pharmacokinetic analysis and Monte Carlo simulations (n = 1000) were performed using NONMEN software. The precision and stability of the final model were analyzed by graphical and statistical methods. Overall, 269 older patients with heart failure were enrolled. A total of 306 digoxin concentrations were collected, with a median value of 0.98ng/mL (interquartile range [IQR] 0.62-1.61, range 0.04-4.24). The median age was 68years (IQR 64-71, range 60-94) and eGFR was 53.6mL/min/1.73m2 (IQR 38.1-65.2, range 11.4-89.8). A one-compartment model with first-order elimination was developed to describe the digoxin pharmacokinetics. Typical values for clearance and volume of distribution were 2.67L/h and 36.9L, respectively. Dosage simulations were stratified by eGFR and metoprolol. Doses of 62.5 and 125μg were recommended for older patients with eGFR < 60mL/min/1.73m2. A population pharmacokinetic model of digoxin in older patients with heart failure and CKD was established in this study. A novel digoxin dosage strategy was recommended in this vulnerable population.

Determining the Risk of Elevated Digoxin Concentrations Following Loading Dose in Patients With Acute and Chronic Kidney Disease.

The optimal loading dose of digoxin in patients with reduced kidney function is unknown. Tertiary references recommend reduced loading doses; however, these recommendations are based on immunoassays that are falsely elevated by the presence of digoxin-like immunoreactive substances, a problem that is minimized in modern assays. To determine whether chronic kidney disease (CKD) or acute kidney injury (AKI) is associated with supratherapeutic digoxin concentrations after a digoxin loading dose. A retrospective analysis on patients who received an intravenous loading dose of digoxin with a digoxin concentration collected 6 to 24 hours after the end of the dose. Patients were stratified into 3 groups: AKI, CKD, and non-AKI/CKD (NKI) based on glomerular filtration rate and serum creatinine. The primary outcome was frequency of supratherapeutic digoxin concentrations (>2 ng/mL) and secondary outcomes included frequency of adverse events. A total of 146 digoxin concentrations were included (AKI = 59, CKD = 16, NKI = 71). Frequencies of supratherapeutic concentrations were similar between groups (AKI: 10.2%, CKD: 18.8%, NKI: 11.3%; P = 0.61). Pre-planned logistic regression demonstrated no significant relationship between kidney function group and the development of a supratherapeutic concentration (AKI: odds ratio [OR]: 1.3, 95% confidence interval [CI]: 0.4-4.5; CKD: OR 4.3, 95% CI: 0.7-23). This is the first study in routine clinical practice evaluating the relationship between kidney function and digoxin peak concentrations that differentiates AKI from CKD. We did not find a relationship between kidney function and peak concentrations; however, the group with CKD was underpowered.

Machine Learning-Based Prediction of Digoxin Toxicity in Heart Failure: A Multicenter Retrospective Study.

Digoxin toxicity (plasma digoxin concentration ≥0.9 ng/mL) is associated with worsening heart failure (HF). Decision tree (DT) analysis, a machine learning method, has a flowchart-like model where users can easily predict the risk of adverse drug reactions. The present study aimed to construct a flowchart using DT analysis that can be used by medical staff to predict digoxin toxicity. We conducted a multicenter retrospective study involving 333 adult patients with HF who received oral digoxin treatment. In this study, we employed a chi-squared automatic interaction detection algorithm to construct DT models. The dependent variable was set as the plasma digoxin concentration (≥ 0.9 ng/mL) in the trough during the steady state, and factors with p < 0.2 in the univariate analysis were set as the explanatory variables. Multivariate logistic regression analysis was conducted to validate the DT model. The accuracy and misclassification rates of the model were evaluated. In the DT analysis, patients with creatinine clearance <32 mL/min, daily digoxin dose ≥1.6 µg/kg, and left ventricular ejection fraction ≥50% showed a high incidence of digoxin toxicity (91.8%; 45/49). Multivariate logistic regression analysis revealed that creatinine clearance <32 mL/min and daily digoxin dose ≥1.6 µg/kg were independent risk factors. The accuracy and misclassification rates of the DT model were 88.2 and 46.2 ± 2.7%, respectively. Although the flowchart created in this study needs further validation, it is straightforward and potentially useful for medical staff in determining the initial dose of digoxin in patients with HF.

Transplacental Therapeutic Drug Monitoring in Pregnant Women with Fetal Tachyarrhythmia Using HPLC-MS/MS.

Fetal arrhythmia develops in 0.1-5% of pregnancies and may cause fetal heart failure and fetal hydrops, thus increasing fetal, neonatal, and infant mortality. The timely initiation of transplacental antiarrhythmic therapy (ART) promotes the conversion of fetal tachycardia to sinus rhythm and the regression of the concomitant non-immune fetal hydrops. The optimal treatment regimen search for the fetus with tachyarrhythmia is still of high value. Polymorphisms of these genes determines the individual features of the drug pharmacokinetics. The aim of this study was to study the pharmacokinetics of transplacental anti-arrhythmic drugs in the fetal therapy of arrhythmias using HPLC-MS/MS, as well as to assess the effect of the multidrug-resistance gene ABCB1 3435C > T polymorphism on the efficacy and maternal/fetal complications of digoxin treatment. The predisposition to a decrease in the bioavailability of the digoxin in patients with a homozygous variant of the CC polymorphism showed a probable association with the development of ART side effects. A pronounced decrease in heart rate in women with the 3435TT allele of the ABCB1 gene was found. The homozygous TT variant in the fetus showed a probable association with an earlier response to ART and rhythm disruptions on the digoxin dosage reduction. high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) methods for digoxin and sotalol therapeutic drug monitoring in blood plasma, amniotic fluid, and urine were developed. The digoxin and sotalol concentrations were determined in the plasma blood, urine, and amniotic fluid of 30 pregnant women at four time points (from the beginning of the transplacental antiarrhythmic therapy to delivery) and the plasma cord blood of 30 newborns. A high degree of correlation between the level of digoxin and sotalol in maternal and cord blood was found. The ratio of digoxin and sotalol in cord blood to maternal blood was 0.35 (0.27 and 0.46) and 1.0 (0.97 and 1.07), accordingly. The digoxin concentration in the blood of the fetus at the moment of the first rhythm recovery episode, 0.58 (0.46, 0.8) ng/mL, was below the therapeutic interval. This confirms the almost complete transplacental transfer of sotalol and the significant limitation in the case of digoxin. Previously, ABCB1/P-glycoprotein had been shown to limit fetal exposure to drugs. Further studies (including multicenter ones) to clarify the genetic features of the transplacental pharmacokinetics of antiarrhythmic drugs are needed.

Evaluation of Safety and Efficacy of Intravenous Digoxin Loading Doses Based on Ideal Body Weight.

Intravenous digoxin loading dose recommendations differ between clinical guidelines and Food and Drug Administration packaging for acute rate control. The objective of this study was to assess the safety and efficacy of intravenous digoxin loading in patients who received ≤12 µg/kg and >12 µg/kg of digoxin using ideal body weight (IBW). This single center retrospective cohort study with exempt status from the local Institutional Review Board included patients who received intravenous digoxin and had a serum digoxin concentration (SDC) drawn. Digoxin doses >36 hours after the first dose were excluded. Patients who received a total of >12 µg/kg and ≤12 µg/kg IBW were compared. The primary endpoint was frequency of SDCs ≥1.2 ng/mL, which have been shown to be associated with increased mortality. A total of 244 patients were included (144 receiving >12 µg/kg and 100 receiving ≤12 µg/kg). There were significantly more SDC ≥1.2 ng/mL in the >12 µg/kg group than the ≤12 µg/kg group (50.6% vs. 30.0%; adjusted odds ratio, 3.19; 95% confidence interval [CI]: 1.79-5.84), with no difference in rate control failure. Major limitations of the study include retrospective nature and possible selection bias. Compared to patients who received digoxin doses ≤12 µg/kg IBW, patients who received >12 µg/kg IBW had higher rates of SDC ≥1.2 ng/mL. This suggests that appropriate weight-based dosing with 8 to 12 µg/kg IBW has the potential to be a safer approach to digoxin loading, rather than frequently used dosing strategies that result in doses >12 µg/kg.

Comparison of creatinine-based equations for estimating renal function for digoxin dose adjustment in patients with atrial fibrillation and heart failure.

The aim of this study was to determine an appropriate equation for estimating renal function to dose regulate the serum digoxin trough concentration to a target of <0.9ng/ml in patients with atrial fibrillation (AF) and heart failure (HF). All patients received 0.125 mg oral digoxin daily. The estimated glomerular filtration rate by the Modification of Diet in Renal Disease (eGFRMDRD ) equation deindexed based on body surface area had the highest correlation with digoxin trough concentrations (r=-0.450) compared to the Cockcroft-Gault equation (r=-0.415) or deindexed eGFR based on the Chronic Kidney Disease Epidemiology Collaboration (eGFRCKD-EPI ) equation (r=-0.416). The median digoxin trough concentrations were 0.60, 0.77, 0.97 and 1.30 ng/ml in patients with a deindexed eGFRMDRD ≥ 60, 45-59, 30-44 and < 30 ml/min, respectively. The deindexed eGFRMDRD is an appropriate equation for digoxin dose adjustment in patients with AF and HF.

Effects of multiple doses of montmorillonite, alone and in combination with activated charcoal, on the toxicokinetics of a single dose of digoxin in rats.

A narrow margin between the therapeutic and toxic doses of digoxin can result in an increased incidence of toxicity. Since digoxin has an enterohepatic cycle, multiple oral doses of absorbents like montmorillonite may be useful in the treatment of digoxin toxicity. In this study, 4 groups of 6 rats received intraperitoneal digoxin (1 mg/kg), and half an hour later, distilled water (DW) or oral adsorbents, including montmorillonite (1 g/kg), activated charcoal (1 g/kg) (AC) alone or in combination in the ratio of 70:30. Half of the mentioned doses were also gavaged at 3 and 5.5 hr after digoxin injection. The serum level of digoxin, biochemical factors, and activity score were assessed during the experiment. Three control groups only received DW, montmorillonite, or AC. All adsorbents were able to significantly decrease the serum level of digoxin compared to the digoxin+DW group (P<0.01). Only montmorillonite reversed the digoxin-induced hyperkalemia (P<0.05). Multiple dose administration of adsorbents also significantly reduced the digoxin area under the curve and half-life and increased digoxin clearance (P<0.05). However, there was no significant difference in the kinetic parameters between groups that received digoxin plus adsorbents. Multiple-dose of montmorillonite reversed digoxin toxicity and reduced serum digoxin levels by increasing the excretion and reducing the half-life. Montmorillonite has also corrected digoxin-induced hyperkalemia. Based on the findings, a multiple-dose regimen of oral montmorillonite could be a suitable candidate for reducing the toxicity issue associated with drugs like digoxin that undergo some degree of enterohepatic circulation.

Effects of rifampin coadministration on the pharmacokinetics of digoxin: a real-world data approach.

Digoxin, a cardiac glycoside, is commonly prescribed to treat heart failure and atrial fibrillation. Because digoxin acts as a substrate of P-glycoprotein (P-gp), its blood concentration may be reduced by P-gp inducers such as rifampin. To assess the real-world implications of this drug-drug interaction, a retrospective analysis was carried out on the Clinical Data Warehouse at Seoul National University Hospital between 2012 and 2017. Eleven patients who received both digoxin and rifampin with satisfying the inclusion/exclusion criteria were identified. The Ctrough values of digoxin monotherapy were compared to those of the combination therapy with rifampin. Results demonstrated that the systemic exposure of orally administered digoxin decreased by 40% with the concurrent use of rifampin. Clinicians should be aware of potential drug interactions between digoxin and rifampin, as adjustments to digoxin dosage might be necessary for patients receiving rifampin or other P-gp inducer drugs.

Lieferengpass Digitoxin

Digitalis glycosides are used control ventricular rate in atrial fibrillation or in advanced heart failure with reduced ejection fraction. There is a bottleneck for digitoxin supply until 2023. Thus, the indications for treatment with Digitalis glycosides should be (re-)evaluated in each case. If there is an indication for treatment with Digitalis, digoxin can be used. As digoxin elimination relies much more on kidney function than digitoxin, overdosing can occur more frequently, especially when renal function worsens. Thus, circulating digoxin levels should be determined more frequently, and lower digoxin dosages should be used in patients with renal insufficiency.

Relationship among surface electric double layer of cardiomyocyte membrane and toxicology of digoxin and opening of ion channels

We applied a new idea that the potential effect can change the ion adsorption structure on the cell surface to explore the mechanism of digoxin poisoning and the regulation of ion channels. The effects of digoxin on the electrophoretic mobility and behaviors (non-contraction or contraction or autorhythmicity) of cardiomyocytes were observed by single-cell electrophoresis technique (imitate the opening method of in vivo channel) and the method of decomposing surface potential components on the cells. As well as affect the association with electrical activity. The results suggested that the increase of cardiomyocytes transmembrane potential and the Na+–K+ exchange on the cell surface of the action potential phase 4 caused by the poisoning dose of digoxin, leading to the oscillation of adsorbed ions on the cell surface and the incomplete channel structure, which were the mechanism of cardiac ectopic beats. The results revealed that the opening of ion channels is regulated by the surface electric double layer of the cell membrane.

UPLC-MS-based Method Development, Validation, and Optimization of Dissolution Using Quality by Design Approach for Low Dose Digoxin: A Novel Strategy

Background: Digoxin, a cardiac glycoside is the one of the most significant drugs of choice for the congestive heart failure treatment. As Digoxin is a BCS class IV drug, the dissolution is a critical quality attribute for its tablet formulation. Methods: Current work aims to quantify the dissolution drug release for low dosage digoxin of 0.0625mg tablets with targeted drug release of more than 80% at 60 minutes by highly sensitive, fast, and versatile UPLC-MS technique. UPLC-MS method operated by positive ionization mode with ACQUITY UPLC C18 (2.1 cm x 100 mm, 1.8 µm) column and flow rate of 0.3ml/min has been developed and validated for parameters like linearity, precision, accuracy, ruggedness, limit of detection (LOD) and limit of quantification (LOQ) as per the ICH guidelines. Results: LOD was found to be 21 ng/mL. Collision energy for digoxin was observed as 35eV for QDa mass detector along with 803.5m/z precursor ion and 651m/z daughter ion. An optimal custom experimental design was employed to optimize the final dissolution conditions. The critical dissolution factors selected for optimization were pH of dissolution media, dissolution media volume, rpm (rotations per minute). The %drug release (DR) was selected as a critical quality attribute with the desired response of drug release &gt;80% at 60minutes. Outcomes of the design were further evaluated by statistical tools including ANOVA. The final optimized dissolution method consists of 500mL of pH 7.4 buffer with a USP apparatus of I (Basket) rotating at 120 rpm. Conclusion: In this current work, we have optimized the dissolution conditions by QbD, and developed a sensitive UPLC-MS method for quantification of digoxin, that can be used in routine quality control purposes efficiently in dissolution testing and quantification of batches of low dose digoxin tablets.