Effect of Aging on the Incidence of Digoxin Toxicity

Abstract

Increased age is most likely associated with enhanced susceptibility to digoxin toxicity, possibly due to unknown pharmacodynamic changes. This raises the possibility that patients >71 years show clinical evidence of digoxin toxicity despite having SDCs within the recommended therapeutic range.

Assessment of the Appropriateness of Serum Digoxin Concentration Measurement in a Medical Group Setting

“…11,12 The DIG trial also showed that SDC values below 0.5 ng per mL provided effective symptom control for heart failure in many patients. A study by Miura et al (2000) evaluated the relationship between SDC values and the incidence of digoxin toxicity in 899 Japanese patients receiving digoxin for heart failure, atrial fibrillation, or atrial fibrillation with tachycardia. 13 Noncardiac symptoms of toxicity were common when SDC values were between 1.4 ng per mL and 2.0 ng per mL but did not occur with SDC values less than 1.4 ng per mL.…”

“…A study by Miura et al (2000) evaluated the relationship between SDC values and the incidence of digoxin toxicity in 899 Japanese patients receiving digoxin for heart failure, atrial fibrillation, or atrial fibrillation with tachycardia. 13 Noncardiac symptoms of toxicity were common when SDC values were between 1.4 ng per mL and 2.0 ng per mL but did not occur with SDC values less than 1.4 ng per mL. Increasing age was shown to be a major predisposing factor for digoxin toxicity independent of renal function, and the authors suggested that the SDC therapeutic range for patients aged 70 years or older be redefined as 0.5 ng per mL to 1.4 ng per mL.…”

Guidelines for Therapeutic Drug Monitoring of Cardiovascular Drugs Clinical Use of Blood Drug Concentration Monitoring (JCS 2015) ― Digest Version ―

“…44, 56 A study in Japanese patients has indicated that the risk of gastrointestinal ADRs increases at digoxin concentrations of ≥1.5 ng/mL, 57 while another study reported extracardiac ADRs did not developed at digoxin concentrations of <1.4 ng/mL. 58 The purpose of blood concentration monitoring of digoxin is the prevention of ADRs, especially extracardiac ADRs, and digoxin should be administered at minimum effective concentrations. Based on the published studies, it is considered appropriate to target a blood digoxin concentration of (0.5 to) 1.5 ng/mL.…”

Aging Biology and Geriatric Clinical Pharmacology

“…In a study of 25 nursing home residents aged 62 to 91 years, it was found that digoxin dosing based on the Cockcroft-Gault equation did not predict subsequent serum levels (Mooradian and Wynn, 1987). Even so, lower doses of digoxin are often recommended and used in older people to avoid concentration-dependent adverse effects (Miura et al, 2000). The converse effects of this approach on the efficacy of digoxin are unknown.…”