[Radioimmunologic determination of serum digoxin. Methodological and 1st clinical experiences].

The tested quality signs of the digoxin-RIA (Medica) correspond to other RIA-test methods. The digoxin-RIA (Medica) is, therefore, well suited for clinical examinations. In the dilanacin- (digoxin-) long-term therapy with the maintenance dose of 0.5 mg digoxin a day 75.4% of the patients examined (n = 65) were within the therapeutic field. In each case 12.3% were underdigitalised or overdigitalised, respectively. In the 8 patients in the toxic region only the half showed signs of digoxin intoxication. It is referred to the importance of creatinine and potassium in the serum, the digoxin clearance depending on age, the body weight and the body surface, respectively, in very obese patients for the height of the serum digoxin level and for the compatibility of this heart glycoside.