ISSN:
1432-1041
Keywords:
Digoxin
;
4‴-methyldigoxin
;
bis- and monodigitoxosides
;
polar conjugates
;
biliary excretion
;
faecal degradation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Medicine
Notes:
Summary The metabolites of tritiated 4‴-methyldigoxin (MD) has been studied in bile, urine and faeces from 3 patients 24 h after cholecystectomy and T-tube drainage. 5.6–15.6% of the doses were eliminated in bile and 28.5–57.8% in urine within 48 h. In bile after 6 h, approximately 5% of the excreted products were bisglycosides (B) and only traces were monoglycosides (M), whereas 55.3±4.5% were CHCl3-insoluble metabolites. At the same time urine contained 15.5±1.3% CHCl3-insoluble compounds. Anaerobic incubation of bile with a stool suspension (SS) decreased the polar fraction by 64.8±4.5% (n=6); incubation with a previously autoclaved SS decreased it only by 12.7±2.7%. Preincubation of SS with carbenicillin, cephalotin and ampicillin to depress bacterial growth largely suppressed the metabolic activity. TLC-analysis revealed that the decrease in the polar fraction corresponded to an increase of M, whilst MD, digoxin and B were almost unaltered. The results imply that B and M were formed in the liver, B was preferentially eliminated unchanged in bile and M was conjugated to CHCl3-insoluble compounds prior to excretion. The polar conjugates were split by bacterial enzymes in the colon to yield M, which could be detected in faeces.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00560378
Permalink