抄録
Serum digoxin levels (SDL) have been known to be a good indicator for digitalis intoxication since radioimmunoassay (RIA) of serum digoxin level became available. To apply pharmacokinetics and RIA of digoxin to the routine practice of medicine, a new method of estimating digoxin blood levels at steady state was evaluated. Blood digoxin concentration in a blood sample obtained at transition state or 3-6 days after initial dosage was used for the estimation of digoxin level at steady state. The apparent volume of distribution was calculated by using multiple dosing equations based on open linear one compartment model. Phadebas RIA stat assay kits were used for the rapid measurement of serum digoxin levels. In six hospitalized patients receiving oral dose of digoxin (0.125-0.25mg per day), estimated digoxin levels at steady state were compared with the values measured by RIA. The estimated and measured values agreed well with a slight discrepancy ranging from 1.5-13% (m^-=6.8%). The method may prove useful as the practical means of predicting SDL at steady state, which allows assessment of digoxin therapy and change of the regimen, if necessary, before intoxication occurs.
