Serum level monitoring of digoxin in cardiac patients attending Assiut University Hospitals: utility in therapy optimizations.

ABSTRACT

This study addressed the utility of digoxin level monitoring in the optimization of drug therapy. The results revealed toxic serum levels [> ng/ml] only in 91 of the 147 suspected cases. Among 61 patients with inadequate response, low concentrations [<0.7 ng/ml] were noticed. Similarly, in ten patients with non-compliance, very low subtherapeutic levels were observed even to the nil level in 50% of the cases. Accordingly, therapeutic failure of digoxin resulting from under dosage or non-compliance could be detected by TDM that helped in appropriate intervention and in the achievement of optimum clinical outcome. On the other hand, the TDM in clinically controlled cardiac patients indicated that the target concentration of digoxin required to the control heart failure and/or supraventricular arrhythmias could range from 0.7 ng/ml to 2.0 ng/ml. These data indicated that the international therapeutic range [0.7-2.0 ng/ml] of digoxin could be also applied to Upper Egypt cardiac patients. In addition, this study demonstrated the importance of proper sampling time and measurement of serum potassium and creatinine in the interpretation of digoxin level data