Studies on the evidence base in support of digoxin therapeutic drug monitoring.

Abstract

There is a dearth of high level evidence for the benefit of digoxin therapeutic drug monitoring on clinical endpoints. A pilot randomised controlled trial of digoxin TDM was conducted in hospital inpatients. The benefit of the knowledge of the serum digoxin concentration (SDC) in determining the likelihood of digoxin toxicity was assessed by presenting blinded clinicians clinical and SDC data using a computerised interface. The main benefit of the knowledge of the SDC was to reduce the percentage of patients classified as "possibly toxic", and to increase the agreement between clinicians. The study found that an increase in the prevalence of cardiac and non-cardiac manifestations of digoxin toxicity became clear at approximately 1.0 ng/ml which is at the lower end of the currently quoted therapeutic range.