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Updated: Sep 23, 2026

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Published on: July 5, 2022
Toxicokinetics of cotyledoside following intravenous administration to sheep
C J Both1, T Rundberget, G E Swan
1Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa. cbotha@op.up.ac.za
Abstract:
Cotyledoside, a bufadienolide cardiac glycoside, was administered intravenously to sheep in 2 studies. In experiment 1, sheep (n = 4) received 0.0135 mg/kg daily on 5 consecutive days and in the 2nd experiment, sheep (n = 4) received 0.027 mg/kg as a single dose. Jugular blood was collected at different time intervals and kinetic parameters were determined. The data fitted a 1-compartmental model. In both experiments a short half-life (t1/2) and mean residence time (MRT), a relative small volume of distribution (Vd(ss)) and rapid clearance were calculated. In the 1st experiment, t1/2 and MRT increased significantly (P < 0.007) from Day (D) 0 to D4. It is suggested that the rapid decline in plasma cotyledoside concentrations in sheep denotes rapid distribution of cotyledoside to the tissues or extracellular spaces and possible accumulation at the biophase.
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