Effect of administration of activated charcoal and fibre on absorption, excretion and steady state blood levels of digoxin and digitoxin. Evidence for intestinal secretion of the glycosides.

The effects of activated charcoal and fibre on absorption and stationary plasma levels of digoxin and digitoxin have been studied. The effect of fibre alone is small but an interactive effect on absorption may occur if fibre and digoxin are ingested simultaneously. Charcoal effectively decreases glycoside absorption even when administered after the glycosides. During maintenance therapy with digoxin or digitoxin, charcoal administration decreased the glycoside plasma levels by 31.2% and 18.3% respectively. It is suggested that even digoxin may have a significant biliary excretion and enterohepatic circulation or that this glycoside has a significant intestinal secretion. The therapeutic implication of this study is that charcoal may be of value, not only in the management of acute glycoside poisoning, but also in some cases of more chronic intoxication.