ISSN:
1432-1912
Keywords:
Cardioglycoside
;
Labelled Compound
;
Drug Metabolism
;
Pharmacokinetics
;
Absorption
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary β-Methyl-digoxin was much more resistant to enzymatic degradation than digoxin, β-acetyl-digoxin and digitoxin. Only in the bile was an appreciable percentage of the radioactivity attributable to a hydrophilic metabolite. The distribution volume of β-methyl-digoxin increased with time, but was independent of the dose and of the mode of administration. The blood levels during i. v. infusion and after i. d. injection can be used for calculating the speed of absorption during the first 20 min only. The correlations between blood levels and pharmacodynamic activity were investigated by varying the dose injected intraduodenally or the speed of i. v. infusion. Although the effective doses were constant, the blood levels expected at the onset of arrhythmias decreased with decreasing speed of administration. Signs of acute tolerance were observed when the experiment lasted for more than 30 min. In the heart, the equilibrium between blood and tissue levels of radioactivity was reached sooner than in the rest of the body. Whereas maximal blood levels were observed about 30 min after oral administration in man, they continued to rise for at least 60 min after i.d. injection in guineapigs. This confirms earlier observations that β-methyl-digoxin is absorbed more rapidly in man than in guinea-pigs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00498793
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