Cardiac glycosides, like digitalis Purpurea, are absorbed through the intestine. Their absorption is regulated by their polarity. Better absorption is increased when the glycoside is more non-polar and lipid-soluble. Digitalis is very nonpolar and therefore has a high absorption rate.

-95-100% intestinal absorption rates.

-Solutions havea higher abosrption rate than solution forms of digitalis.

-Absorption is decreased when intestinal function is decreased or with intestinal hypermortility, as in the case with the use of the drug metoclopramide.

-Anticholinergic drugs, which cause intestinal hypomotility, increase abosorption.
Patients with congestive heart failure have trouble absorbing the digitalis since their intestinal mucosa is not well perfused. Intravenous introduction of digitalis is highly effective inthis case.

From: J.E. Doherty, W. H. Perkins, W. J. Flanigan,Ann. int. med. 66:116, 1967.
Return to Main Page

Return to Pharmacology/Biochemistry Page