Pharmacokinetics of digoxin in the turkey and comparison with other species

Digoxin was administered by bolus intravenous injection to seven broad-breasted white turkey poults at doses of 0.1, 0.15, or 0.2 mg/kg. Plasma digoxin concentrations were measured by a 125I radioimmunoassay at selected times over the subsequent 24 hr. The data were fitted to a two compartment open pharmacokinetic model. Overall mean values for kinetic variables were: distribution halflife, 38.96 min; elimination halflife, 11.03 hr; volume of distribution in the central compartment, 1.54 liters/kg; total body clearance, 5.81 ml/min/kg. Different doses did not appear to have a significant effect on the identifiable pharmacokinetic variables, suggesting that digoxin disposition is dose independent in the turkey. The results obtained in turkeys were compared with data reported for rats, cats, dogs, and humans. The value for total body clearance of digoxin in the turkey was similar to values found in man, dogs, and cats but considerably less than values reported for rats. The value for elimination halflife in turkeys was somewhat less than values reported for infants and dogs; however, it was considerably different than values reported for rats and cats.