Digoxin disposition kinetics in dogs before and during azotemia.
The purpose of this study was to evaluate the disposition kinetics of digoxin after the administration of a single intravenous dose to the same dogs before and during azotemia. The digoxin plasma concentration-time data were fitted to a multicompartment model using nonlinear regression analysis. During azotemia, the biological half-life of digoxin was prolonged in six of seven dogs, while digoxin renal clearance, body clearance and apparent volume of distribution were significantly decreased. There was a corresponding increase in the apparent volume of the "central" compartment of digoxin. Approximately 45% of a digoxin dose was excreted by the kidney in these animals indicating a substantial nonrenal component to digoxin elimination in the dog. This nonrenal elimination did not change during azotemia, despite a decrease in renal clearance by 61%.
D000818:Animals; D003404:Creatinine / Q000378:metabolism; D004077:Digoxin / Q000378:metabolism*; D004285:Dogs; D007700:Kinetics; D008297:Male; D014511:Uremia / Q000378:metabolism*
D004077:Digoxin; D003404:Creatinine