An altered distribution and elimination of digoxin in anemic patients and experimentally induced anemic rats

Digoxin was administered orally to eight anemic patients in their anemic and convalescent stages, and serum digoxin concentration was determined by radioimmunoassay. In the anemic patients a significantly lower level of serum digoxin concentration was observed in anemic state compared with convalescent stage at 72 hours after the drug administration (p less than 0.01). In usual clinical use, a full digoxin effect is expected to be attained as 72 hours. Tritiated digoxin was administered intravenously to anemic and control rats and the tritium in samples of the blood, myocardium and urine were counted in a liquid scintillation counter. The anemic rats showed significantly lower level of serum 3H-digoxin at 6 hours (p less than 0.01) and lower myocardial concentration at 24 hours (p less than 0.01). Larger amount of urinary excretion of 3H-digoxin was observed in the anemic rats 6 hours after the drug administration. No significant difference in fecal excretion of 3H-digoxin was found between the anemic and control rats.