In the first part of this paper (A.M.A. Arch. Int. Med. 101:849 [May] 1958), an attempt was made to describe the graded toxic response to digitalis as a phenomenon which exhibits varying degrees of reversibility when antagonized by potassium salts depending on the existing level of intoxication. In the dog, at relatively low levels of K-strophanthin intoxication, potassium in the form of any of its soluble organic or inorganic salts appears capable of reversing electrocardiographic evidence of toxicity. At higher levels of intoxication, however, only the L-glutamic and α-keto glutaric acid salts still retain this antidotal property.
It is obviously impossible to delineate precisely any given level of intoxication on the basis of a fixed dose per unit weight in the experimental animal because of variations in toxicity thresholds resulting from fluctuations in total-body potassium stores as well as their distribution in extracellular and intracellular spaces. The relationship of digitalis