[An increase in plasma digoxin levels after discontinuation of therapy].

In this paper, a course of the disease of a 68-year-old patient treated with medigoxin for congestive heart failure is presented. After being withdrawn from his treatment at the hospital, the patient was administered spironolactone and furosemide. The plasma digoxin level at entry was 1.1 nmol/L, after five days it reached 3.2 nmol/L, and after ten days it was 2.3 nmol/L. The patient had a normal renal function. The interference of spironolactone and its metabolites with the digoxin radioimmunoassay was discussed as a possible explanation for this phenomenon.