Strophanthus would seem to be absorbed from the alimentary tract with less rapidity and more uncertainty than digitalis (Hatcher). It is at least 50 times as poisonous to the heart muscle (Haynes, Edmunds, Houghton).

Either strophanthin of the Pharmacopoeia, or ouabain (crystalline gratus strophanthin), may be dissolved in salt solution and given by deep intramuscular injection or intravenously. When 1/65 grain (1 mg.), the maximum dose, is passed into a vein of a human being, it may show its results in slowing of the pulse in from one-half to one hour, with strengthening of the heart. Provided that digitalis has not already been given, this treatment may be employed when the symptoms of the cardiac weakness are very severe, and particularly if there is auricular fibrillation.

Strophanthin is said to be eliminated much more rapidly by the kidneys than the digitalis glucosides, so that cumulative poisoning does not occur. To test this Frankel gave submaximal doses to a cat for ninety-two days and got no symptoms of overdosage; Hatcher's work corroborates this. In poisoning, there is no striking constriction of the systemic arteries; and Dixon has shown by a perfusion experiment that while one part of the tincture of digitalis in 2500 was sufficient to constrict strongly the coronary arteries of a rabbit, a similar strength of the tincture of strophanthus had no effect. In a number of cases the appearance of diarrhea is a bar to the use of strophanthus, and this is attributed to a direct action of strophanthin on the intestinal muscles.

Two things in the action of strophanthus must be especially noted, first, its smaller power to relieve conditions due to failure of compensation, except when used intravenously; and, second, its great toxicity to the muscle of the heart.

Convallaria has no advantages over digitalis and is more toxic.

Helleborein, dose, 1/2 grain (0.03 gm.), has been found experimentally to have muscular effects similar to those of digitalis, but without its vagus effects. Its application in therapeutics has not been determined.