Use of digoxin in a low density population area in Sweden

Summary

Plasma digoxin was measured in all patients receiving digoxin (Lanacrist, Draco) in a well-defined low density population area in Sweden. The number of treated patients (n=75) corresponded to 3 % of the population. The average prescribed daily dose of digoxin was 0.25 mg, and the mean plasma concentration (n=74) was 0.85 (S.D. 0.52) ng/ml. Of the concentrations found 3 % were above and 62 % were below the apparent therapeutic range, 1 – 2 ng/ml. The findings were compared with analyses performed in a hospital laboratory (n=300), the majority being inpatients receiving a similar daily dose. In the latter, 22 % had a plasma level above and about 33 % below the apparent therapeutic range. In the former group no difference in plasma digoxin concentration could be demonstrated between patients treated with digoxin (n=34) and those treated with both digoxin and diuretics (n=40). In a group of eight patients plasma digoxin rose significantly after they were informed of the importance of taking their medicine regularly. Poor compliance with prescribed therapy was even documented in patients in cardiac failure.