RESUMEN
The effect of a short-term treatment with captopril on IV bolus digoxin kinetics has been investigated in 6 normal dogs. A dose of 0.05 mg/kg digoxin was given to each dog and blood samples were collected for digoxin assay. The dogs were then given captopril [20 mg/kg orally] for 10 days followed by a similar IV bolus dose of digoxin and blood samples were also collected for digoxin assay. The results showed that serum digoxin concentration-time curve declined biphasically in the first 24 hours after administration. The Cp max significantly decreased by 39%, while the t max was prolonged by 64%. The distribution of digoxin in the central compartment [t/1/2 alpha and Vc] was not statistically different under the effect of Captopril while the elimination phase half life [T/1/2 alpha and beta] was longer by 106% and the apparent volume of distribution [Vd] was increased by 85%. The area under the curve [AUC] was increased by 17%. These changes indicated that Captopril can reduce digoxin elimination as shown by the reduction in digoxin clearance and the increase in the AUC