EFFECT OF INGESTA AND OF TABLETS OF DIFFERENT STRENGTHS ON THE SYSTEMIC AVAILABILITY OF DIGOXIN IN NORMAL DOGS

The plasma concentrations of digoxin were measured in eight normal dog s given digoxin on four occasions, using three different feeding regim ens and tablets of two strengths. Although ingesta tended to slow the absorption of digoxin, the systemic availability of the drug, based on measurements of C-max, t(max), and AUC did not differ when digoxin ta blets were given with canned food, with dry food, or without food. How ever, some of the pharmacokinetic characteristics and smaller individu al variations with the dry food regimen would be considered advantageo us for maintenance therapy. Tablets containing 62.5 pg or 250 mu g of digoxin had a similar relative bioavailability. The peak plasma digoxi n concentrations were higher in female dogs, and the trends in other d ata also suggested that the systemic availability of digoxin was bette r in female dogs.