Beta-blockers or Digoxin for Atrial Fibrillation and Heart Failure?

Drug therapy monitoring (TDM) of Digoxin: safety and efficacy review

Digoxin was developed as a novel medication for the treatment of heart failure and atrial fibrillation (AF) 200 years ago. This investigation began with a PubMed and Google Scholar search for various papers using the terms digoxin safety and efficacy, digoxin in heart failure, and digoxin in atrial fibrillation. Digoxin should be administered at a dose of 0.5–0.7 ng/mL in individuals with heart failure and reduced ejection fraction. Digoxin should be administered to decrease hospital readmissions, although SDC, creatinine, and potassium levels should be continuously maintained to limit the risk of toxicity. Digoxin may be used in conjunction with diuretics, spironolactone, ACE inhibitors, or beta-blockers. It is preferable to take digoxin on a regular basis. Digoxin should not be used in the pre-excitation syndrome because it can result in the rapid development of accessory route conductors, which can finally result in ventricular fibrillation. Due to the narrow therapeutic index of digoxin, it requires appropriate treatment and continuous monitoring.

Benefits of prescribing low-dose digoxin in atrial fibrillation

INTRODUCTION

The role of digoxin (cardiac glycoside) in controlling the heart rate (HR) for the treatment of atrial fibrillation (AF) patients has not been explored in depth.

METHODS

To contribute to the limited data, our team conducted retrospective analysis of the clinical records of 1444 AF patients. We divided the AF patients into two groups, wherein group 1 patients were treated with beta-blockers (BB), low-dose digoxin, and an anticoagulant (vitamin K antagonist/factor-IIa inhibitor/factor-Xa inhibitor), and group 2 patients were treated with just BB and an anticoagulant. Our objectives were to compare the impact of combination therapy of BB and digoxin on the resting HR in patients with permanent AF and the patients' quality of life (QOL) at periodic intervals.

RESULTS

The findings of our study showed a better control of the resting HR rate (<110bpm) and an improved QOL among the group 1 patients when compared with group 2 patients.

CONCLUSION

Our findings are indicative of the favorable clinical outcomes that resulted from the addition of a low-dose of digoxin to the AF treatment regimen. However, larger studies/trials elucidating the outcomes of AF patients treated with the dual rate control therapy are required, to clarify the role of digoxin, guide the choice of agents, and standardize the AF treatment protocol.

Perceived risk profile and treatment optimization in heart failure: an analysis from BIOlogy Study to TAilored Treatment in chronic heart failure

Background

Achieving target doses of angiotensin‐converting‐enzyme inhibitor/angiotensin‐receptor blockers (ACEi/ARB) and beta‐blockers in heart failure with reduced ejection fraction (HFrEF) is often underperformed. In BIOlogy Study to TAilored Treatment in chronic heart failure (BIOSTAT‐CHF) study, many patients were not up‐titrated for which no clear reason was reported. Therefore, we hypothesized that perceived‐risk profile might influence treatment optimization.

Methods

We studied 2100 patients with HFrEF (LVEF≤40%) to compare the clinical characteristics and adverse events associated with treatment up‐titration (after a 3‐month titration protocol) between; a) patients not reaching target doses for unclear reason; b) patients not reaching target doses due to symptoms and/or side effects; c) patients reaching target doses.

Results

For ACEi/ARB, (a), (b) and (c) was observed in 51.3%, 25.9% and 22.7% of patients, respectively. For beta‐blockers, (a), (b) and (c) was observed in 67.5%, 20.2% and 12.3% of patients, respectively. By multinomial logistic regression analysis for ACEi/ARB, patients in group (a) and (b) had lower blood pressure and poorer renal function, and patients in group (a) were older and had lower ejection fraction. For beta‐blockers, patients in group (a) and (b) had more severe congestion and lower heart rate. At 9 months, adverse events (i.e., hypotension, bradycardia, renal impairment, and hyperkalemia) occurred similarly among the three groups.

Conclusions

Patients in whom clinicians did not give a reason why up‐titration was missed were older and had more co‐morbidities. Patients in whom up‐titration was achieved did not have excess adverse events. However, from these observational findings, the pattern of subsequent adverse events among patients in whom up‐titration was missed cannot be determined.

Pharmacokinetics Parameters of Diagoxin among Saudi Patients in Qassim Region, Saudi Arabia

BACKGROUND

The pharmacodynamic effects of digoxin are susceptible to multiple factors, most notably, heart uptake of the digoxin dose and its concentration in the serum. Another important factor to mention is the renal function state of an individual.

OBJECTIVE

In this study, we aimed to develop a simple algorithm based on subsets of clinically relevant information, which will help to personalize digoxin based on pharmacokinetic (PK) approach, which can help on marketing the appropriate utilization of this medication.

METHOD

This was a retrospective chart review and analysis of 48 patients who were admitted to the Drug and Poison Information Center in Buraidah, Saudi Arabia, between January 2016 and April 2019. All pharmacokinetic parameters were added according to the C-peaks and C-troughs. MONOLiX® was used for pharmacokinetic data analysis.

RESULTS

Twenty-seven (56%) were males, and twenty-one (44%) were females with an average age of 63.6 years across both genders. The mean volume of distribution was 496.6 litres with an average clearance of 6.6 L/h. For females, their average volume of distribution was slightly higher than that for males (526 litres compared to 473 liters). In addition, the clearance rate between both genders showed a 2.1 litre/hour discrepancy (7.8 L/h for females compared to 5.7 L/h for males).

CONCLUSION

In order to individualize the digoxin dosage regimens, this model can be used to predict digoxin serum concentration. Further studies are needed to clarify the effects of nutritional status and co-administration of medications on digoxin pharmacokinetics.

Evaluation of the prescribing practice of guideline-directed medical therapy among ambulatory chronic heart failure patients

BACKGROUND

Studies have demonstrated that heart failure (HF) patients who receive direct pharmacist input as part of multidisciplinary care have better clinical outcomes. This study evaluated/compared the difference in prescribing practices of guideline-directed medical therapy (GDMT) for chronic HF patients between two multidisciplinary clinics-with and without the direct involvement of a pharmacist.

METHODS

A retrospective audit of chronic HF patients, presenting to two multidisciplinary outpatient clinics between March 2005 and January 2017, was performed; a Multidisciplinary Ambulatory Consulting Service (MACS) with an integrated pharmacist model of care and a General Cardiology Heart Failure Service (GCHFS) clinic, without the active involvement of a pharmacist.

RESULTS

MACS clinic patients were significantly older (80 vs. 73 years, p < .001), more likely to be female (p < .001), and had significantly higher systolic (123 vs. 112 mmHg, p < .001) and diastolic (67 vs. 60 mmHg, p < .05) blood pressures compared to the GCHF clinic patients. Moreover, the MACS clinic patients showed more polypharmacy and higher prevalence of multiple comorbidities. Both clinics had similar prescribing rates of GDMT and achieved maximal tolerated doses of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in HFrEF. However, HFpEF patients in the MACS clinic were significantly more likely to be prescribed ACEIs/ARBs (70.5% vs. 56.2%, p = 0.0314) than the GCHFS patients. Patients with both HFrEF and HFpEF (MACS clinic) were significantly less likely to be prescribed β-blockers and mineralocorticoid receptor antagonists. Use of digoxin in chronic atrial fibrillation (AF) in MACS clinic was significantly higher in HFrEF patients (82.5% vs. 58.5%, p = 0.004), but the number of people anticoagulated in presence of AF (27.1% vs. 48.0%, p = 0.002) and prescribed diuretics (84.0% vs. 94.5%, p = 0.022) were significantly lower in HFpEF patients attending the MACS clinic. Age, heart rate, systolic blood pressure (SBP), anemia, chronic renal failure, and other comorbidities were the main significant predictors of utilization of GDMT in a multivariate binary logistic regression.

CONCLUSIONS

Lower prescription rates of some medications in the pharmacist-involved multidisciplinary team were found. Careful consideration of demographic and clinical characteristics, contraindications for use of medications, polypharmacy, and underlying comorbidities is necessary to achieve best practice.