Metabolism and excretion of digitoxin in man

Publisher Website
Google Scholar
Abstract
The levels of digitoxin and its metabolites in the plasma, urine, and feces of 6 subjects given a single oral dose of 1 mg 3H‐dgt have been determined using CHCl3‐extraction and thin‐layer chromatography (TLC). The peak plasma level of 4.1% of the given dose per 1 plasma occurred at 40 min after drug administration and was followed by an exponential decline with a mean half‐life (T/2) of 6.8 days. The T/2 of the eliminated radioactivity in urine and feces was 7.2 and 4.8 days, respectively. Within 192 hr, 22% of the given dose has been excreted in urine and 13% in feces. The TLC separation of the CHCl2‐soluble fraction in plasma yielded the unchanged digitoxin (dgt) and traces of digitoxigenin‐bisdigitoxoside (dgt‐bis). In urine, dgt accounted for 60% of the eliminated amount within the experimental time. Dgt‐bis and the hydroxylated products digoxin (dg) and dgt‐bis were also found in lesser anwunts. The monodigitoxoside of digitoxigenin (dgt‐mono) could be denwnstrated as a conjugative partner of glucuronic acid. In feces, the unchanged dgt and its monoderivative were the main excretion products. However, since dgt‐mono and the more polar compounds have shown an inverse relationship during the study, a bacterial cleavage following a conjugation of dgt‐mono and an enterohepatic circulation of its lipophilic nwiety are suggested. These results demonstrate the limited degradation of dgt in man and suggest that the pharmacologic effects are mediated by dgt itself.

This publication has 0 references indexed in Scilit: