The radioimmunoassay of plasma-digoxin

Abstract

Our experience with a commercially available kit (Lanoxitest) for the serum digoxin determination by radioimmunoassay using [ 3H]digoxin is reported. The different steps of the procedure are evaluated. Some modifications, especially a reduction of the time of adsorption from 10 to 1 min, lead to more accurate results. A “cito” determination can be fully completed in 1 1 2 h. Mean digoxin value in 93 non-toxic patients with normal renal function was 1.6 ng/ml (S.D. = ± 0.7 ng/ml). 22 patients, showing toxicity attributed to digoxin, had a mean level of 4.4 ng/ml (S.D. = ± 0.9 ng/ml).